Journal articles: 'Radar geology'

1

Budiono, Kris, and Godwin Latuputty. "SUBSURFACE GEOLOGICAL CONDITION OF SEVERAL LAND COASTAL ZONE IN INDONESIA BASED ON THE GSSI GROUND PROBING RADAR (GPR) RECORD INTERPRETATION." BULLETIN OF THE MARINE GEOLOGY 23, no. 1 (February 15, 2016): 9. http://dx.doi.org/10.32693/bomg.23.1.2008.6.

Full text

Abstract:

The GSSI Ground Penetrating radar have been used to profile the shallow depth of subsurface geology of several area of Land Coastal zone in Indonesia Analysis of a large data base of GPR profile from natural subsurface geological condition along the land coast line have allowed identification of reflection configuration that characterize this type of sub surface geological environment. In many contamination problem, the geological information of coastal area is sparse and drill-core description only gives a limited picture of the geometry of inhomogeneties. The Ground-Probing Radar (GPR) method is a promising tool for resolving changes of physical properties in subsurface geological condition at the scale of natural inhomogeneties arising from changing lithology composition. The objective of present work are to examine whether and to what extent the characteristic lithofacies of subsurface lithology can be recognised as mapable reflection pattern on ground probing radar (GPR) reflection profiles in order to gain information about the subsurface geometry of subsurface geology in coastal area. Key word: Subsurface geology, coastal zone, Ground Probing Radar Ground probing radar produksi GSSI telah dipergunakan untuk membuat penampang geologi bawah permukaan dangkal di beberapa kawasan pantai Indonesia. Analisa data dasar penampang GPR dari geologi bawah permukaan di kawasan pantai dapat memperlihatkan konfigurasi reflector yang mencerminkan jenis lingkungan geologi bawah permukaan. Dalam masalah kontaminasi, informasi geologi di daerah pantai yang dihasilkan dari pemboran inti hanya dapat memperlihatkan gambaran yang sederhana tentang geometri ketidakseragaman. Metoda ground probing radar merupakan alat bantu yang menjanjikan untuk menanggulangi masalah sifat fisik kondisi geologi bawah permukaan pada skala ketidak seragaman yang sebenarnya dari perubahan komposisi litologi. Tujuan utama dari penelitian ini adalah untuk menguji sampai sejauh mana karakteristik litofasies dari litologi bawah permukaan dapat dilihat sebagai pola refleksi yang dapat dipetakan dalam penampang GPR dengan maksud untuk mendapatkan informasi geometri geologi bawah permukaan di daerah pantai. Kata kunci: Geologi bawah permukaan, zona pantai, â€œGround probing radarâ€

APA, Harvard, Vancouver, ISO, and other styles

2

Budiono, Kris, and Yogi Noviadi. "INVESTIGATION OF GROUND PENETRATING RADAR FOR DETECTION OF ROAD SUBSIDENCE NORTHCOAST OF JAKARTA, INDONESIA." BULLETIN OF THE MARINE GEOLOGY 27, no. 2 (February 15, 2016): 87. http://dx.doi.org/10.32693/bomg.27.2.2012.48.

Full text

Abstract:

A survey of Ground Penetrating Radar (GPR) was conducted in the coastal zone of northern part of Jakarta, Indonesia. The purpose of this survey was to provide the subsurface of coastal Quaternary sedimentary features and stratigraphy disturbances associated with induce post road subsidence 2009. The possibility of subsurface lithology disturbance shown by the GPR record. This record resulted from GPR methods using SIR system 20 GSSI, 270 MHz and 400 MHz and MLF 3200 transducer. The method is a promising tool for resolving changes of physical properties in subsurface lithology condition at the natural scale due to composition changes of physical properties.The reflection data resulted that GPR can distinguish between image the basic geometry forms such as lithology , structure geology , soil and subsurface utilities condition Keywords: Quaternary geology, Jakarta subsidence northern road 2009, Ground Penetrating Radar Penyelidikan â€œGround Penerating Radarâ€ (GPR) telah dilaksanakan di kawasan pantai utara Jakarta Utara, Indonesia. Tujuan dari penyelidikan GPR ini adalah untuk melihat kondisi sedimen Kuarter bawah permukaan dan gangguan stratigrafi sehubungan dengan penurunan jalan raya pada tahun 2009. Kemungkinan gangguan terhadap litologi bawah permukaan terlihat pada rekaman GPR. Hasil rekaman metoda GPR mempergunakan model SIR 20 GSSI, transduser 270MHz, 400 MHz dan MLF 3200.Metoda GPR merupakan alat bantu yang cukup menjanjikan untuk melihat perubahan sifat fisik litologi bawah permukaan pada skala sebenarnya yang disebabkan oleh perubahan komposisi sifat fisiknya. Hasil refleksi data GPR dapat membedakan bentuk dasar geometri seperti litologi, struktur geologi, kondisi utilitas bawah permukaan. Kata kunci : Geologi Kuarter, Penurunan jalan utara Jakarta 2009, Ground Penetrating Radar

APA, Harvard, Vancouver, ISO, and other styles

3

Singhroy, Vernon H. "Radar geology: Techniques and results." Episodes 15, no. 1 (March 1, 1992): 15–20. http://dx.doi.org/10.18814/epiiugs/1992/v15i1/004.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Singhroy, V., R. Slaney, P. Lowman, J. Harris, and W. Moon. "RADARSAT and Radar Geology in Canada." Canadian Journal of Remote Sensing 19, no. 4 (November 1993): 338–51. http://dx.doi.org/10.1080/07038992.1993.10874569.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Ernst, Jacques R., Alan G. Green, Hansruedi Maurer, and Klaus Holliger. "Application of a new 2D time-domain full-waveform inversion scheme to crosshole radar data." GEOPHYSICS 72, no. 5 (September 2007): J53—J64. http://dx.doi.org/10.1190/1.2761848.

Full text

Abstract:

Crosshole radar tomography is a useful tool in diverse investigations in geology, hydrogeology, and engineering. Conventional tomograms provided by standard ray-based techniques have limited resolution, primarily because only a fraction of the information contained in the radar data (i.e., the first-arrival times and maximum first-cycle amplitudes) is included in the inversion. To increase the resolution of radar tomograms, we have developed a versatile full-waveform inversion scheme that is based on a finite-difference time-domain solution of Maxwell’s equations. This scheme largely accounts for the 3D nature of radar-wave propagation and includes an efficient method for extracting the source wavelet from the radar data. After demonstrating the potential of the new scheme on two realistic synthetic data sets, we apply it to two crosshole field data sets acquired in very different geologic/hydrogeologic environments. These are the first applications of full-waveform tomography to observed crosshole radar data. The resolution of all full-waveform tomograms is shown to be markedly superior to that of the associated ray tomograms. Small subsurface features a fraction of the dominant radar wavelength and boundaries between distinct geological/hydrological units are sharply imaged in the full-waveform tomograms.

APA, Harvard, Vancouver, ISO, and other styles

6

Zhu, Chun Jie, Fei Liu, and Jun Dong. "Structure Detection and Evaluation of the Highway Tunnel." Advanced Materials Research 1020 (October 2014): 405–10. http://dx.doi.org/10.4028/www.scientific.net/amr.1020.405.

Full text

Abstract:

Combined with a highway tunnel testing and assessment, through the discussing of technical problems existed in tunnel’s quality detecting by the using of geology radar, using gist of geology radar in tunnel’s quality detecting is grasped, the key technologies of survey line layout, acquisition parameters setting and on-site test in the process of geological radar application are concluded. Relying on the field test data, lining thickness and dense degree of the left and right of spandrel and arch crown being in the safe use of phase are more deeply researched. The studies show that geological radar detection technology for tunnel nondestructive testing and evaluation is a kind of effective method, correlation detection technique and analysis method has some reference value to the similar tunnel structure.

APA, Harvard, Vancouver, ISO, and other styles

7

Xiao, Qiao Lin, and Fen Lü. "Application Research of Geological Radar in Volcanic Lava in the Geological Survey." Applied Mechanics and Materials 226-228 (November 2012): 2093–97. http://dx.doi.org/10.4028/www.scientific.net/amm.226-228.2093.

Full text

Abstract:

Aiming at the Hainan volcanic lava the geological characteristics, the application of geological radar detection technology in the geological environment of signal respond, combined with the added drilling data is compared, established the goal of geological radar image characteristics of geology, summarized the poor geological conditions in the area of geological radar signal response law. Field test shows that the radar reflected wave group of wave characteristic in volcanic lava can distinguish different geological layer reflection wave group, and via studying their relationship and change trend, to achieve the purpose of geological interpretation, and determine the adverse lava geology development stages , for design and construction to provide the reliable foundation material, effective use of survey for the design and construction of the guidance function.

APA, Harvard, Vancouver, ISO, and other styles

8

Krajewski, Witold F., Anton Kruger, Satpreet Singh, Bong-Chul Seo, and James A. Smith. "Hydro-NEXRAD-2: real-time access to customized radar-rainfall for hydrologic applications." Journal of Hydroinformatics 15, no. 2 (December 6, 2012): 580–90. http://dx.doi.org/10.2166/hydro.2012.227.

Full text

Abstract:

Hydro-NEXRAD-2 (HNX2) is a prototype system that allows hydrologic users real-time access to NEXRAD radar data in support of a wide range of research. The system processes basic radar data (Level II) and delivers radar-rainfall products based on the user's custom selection of features such as spatial domain, rainfall product space and time resolution, and rainfall estimation algorithms. HNX2 collects real-time, unprocessed data from multiple NEXRAD radars as they become available, processes them through a user-configurable pipeline of data-processing modules, and publishes the processed data-products at regular intervals. Modules in the data-processing pipeline encapsulate algorithms such as non-meteorological echo detection, radar range correction, radar-reflectivity-rain rate (Z-R) conversion, echo advection correction, mosaicking of products from multiple radars, and grid projections and transformations. This paper describes the challenges involved in HNX2's development and implementation, which include real-time error-handling, time-synchronization of data from multiple asynchronous sources, generation of multiple-radar metadata products, and distribution of products to a user base with diverse needs and constraints. HNX2 publishes products through automation and allows multiple users access to published products. Currently, HNX2 is serving near real-time rain-rate maps for Iowa in the USA using data from seven radars covering the state. Hydrologic models operated by The University of Iowa's Iowa Flood Center use these products.

APA, Harvard, Vancouver, ISO, and other styles

9

Vivekanandan, J., W. C. Lee, E. Loew, J. L. Salazar, V. Grubišić, J. Moore, and P. Tsai. "The next generation airborne polarimetric Doppler weather radar." Geoscientific Instrumentation, Methods and Data Systems 3, no. 2 (July 21, 2014): 111–26. http://dx.doi.org/10.5194/gi-3-111-2014.

Full text

Abstract:

Abstract. Results from airborne field deployments emphasized the need to obtain concurrently high temporal and spatial resolution measurements of 3-D winds and microphysics. A phased array radar on an airborne platform using dual-polarization antenna has the potential for retrieving high-resolution, collocated 3-D winds and microphysical measurements. Recently, ground-based phased array radar (PAR) has demonstrated the high time-resolution estimation of accurate Doppler velocity and reflectivity of precipitation and clouds when compared to mechanically scanning radar. PAR uses the electronic scanning (e-scan) to rapidly collect radar measurements. Since an airborne radar has a limited amount of time to collect measurements over a specified sample volume, the e-scan will significantly enhance temporal and spatial resolution of airborne radar observations. At present, airborne weather radars use mechanical scans, and they are not designed for collecting dual-polarization measurements to remotely estimate microphysics. This paper presents a possible configuration of a novel airborne phased array radar (APAR) to be installed on an aircraft for retrieving improved dynamical and microphysical scientific products. The proposed APAR would replace the aging, X-band Electra Doppler radar (ELDORA). The ELDORA X-band radar's penetration into precipitation is limited by attenuation. Since attenuation at C-band is lower than at X-band, the design specification of a C-band airborne phased array radar (APAR) and its measurement accuracies are presented. Preliminary design specifications suggest the proposed APAR will meet or exceed ELDORA's current sensitivity, spatial resolution and Doppler measurement accuracies of ELDORA and it will also acquire dual-polarization measurements.

APA, Harvard, Vancouver, ISO, and other styles

10

Witten, Alan, and John Lane. "Offset vertical radar profiling." Leading Edge 22, no. 11 (November 2003): 1070–76. http://dx.doi.org/10.1190/1.1634910.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Shrestha, N. K., T. Goormans, and P. Willems. "Evaluating the accuracy of C- and X-band weather radars and their application for stream flow simulation." Journal of Hydroinformatics 15, no. 4 (June 13, 2012): 1121–36. http://dx.doi.org/10.2166/hydro.2012.120.

Full text

Abstract:

This paper investigates the accuracy of rainfall estimates from C- and X-band weather radars and their application for stream flow simulation. Different adjustment procedures are applied to raw radar estimates using gauge readings from a network of 12 raingauges. The stream flow is simulated for the 48.17 km2 Molenbeek/Parkbeek catchment located in the Flemish region of Belgium based on a lumped conceptual model. Results showed that raw radar estimates can be greatly improved using adjustment procedures. The gauge-radar residuals however, remain large even after adjustments. The adjusted X-band radar estimates are observed to be better estimates than corresponding C-band estimates. Their application for stream flow simulation showed that raingauges and radars can simulate spatially more uniform winter storms with almost the same accuracy, whereas differences are more evident on summer events.

APA, Harvard, Vancouver, ISO, and other styles

12

Liang, D., T. Balz, Z. Y. Wang, L. H. Wei, and M. S. Liao. "Web-based interactive visualization of PS-InSAR point clouds for education and training." ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences II-6 (April 14, 2014): 7–12. http://dx.doi.org/10.5194/isprsannals-ii-6-7-2014.

Full text

Abstract:

In radar remote sensing education and training, only few people have a good knowledge of radar remote sensing and geology, which would be necessary fully analyse the surface motions estimated by persistent scatterer interferometry. Using scientific visualization, data can be presented in an intuitive way for surface motion analysis of non-radar experts. In this paper, we introduce a web-based interactive visualization of PS-InSAR point clouds for education and training.

APA, Harvard, Vancouver, ISO, and other styles

13

Zuo, Xuzhou, Chunguang Ma, Jianping Xiao, and Qing Zhao. "Application of Borehole Radar Data Processing Based on Empirical Mode Decomposition." Journal of Environmental and Engineering Geophysics 24, no. 3 (September 2019): 409–18. http://dx.doi.org/10.2113/jeeg24.3.409.

Full text

Abstract:

Borehole Radar (BHR) uses ultra-wideband electromagnetic (EM) waves to image discontinuities in formations. It has been a major bottleneck to extend BHR applications to obtain a clear and high-resolution radar profile in a complex and noisy environment, which increases ambiguity in the geology interpretation. To avoid this increased ambiguity in the geology interpretation, we proposed a scheme based on the empirical mode decomposition (EMD) and complex signal analysis theory to process the BHR data with low signal to noise ratio (SNR). The scheme includes four steps. First, the original radar profile is pre-processed to avoid mode confusion and noise interference to the radar echo. Next, the EMD method is used to process a single-channel radar dataset and to analyze the frequency components of the radar signal. Various intrinsic modes of the pre-processing radar profile are also obtained by using EMD. Finally, we reconstruct the intrinsic mode profile, which contains information about the formation, calculate the complex signals of the reconstructed radar profile using the Hilbert transform, extract the three instantaneous attributes (instantaneous amplitude, instantaneous phase, and instantaneous frequency), and draw the separate instantaneous attributes profiles. This processing scheme provides both the conventional time-distance profile also in addition to the three instantaneous attributes. The additional attributes reduce ambiguity when evaluating the original radar profile and avoid the deviation relying solely on a conventional time-distance profile. An actual radar profile, which was obtained by a BHR system in a limestone fracture zone, is used to verify the effectiveness of instantaneous attributes for improving interpretation accuracy. The results demonstrate that the EMD method is superior in processing the BHR signal under a low SNR and has the capability to separate the high-low components of the radar echo effectively.

APA, Harvard, Vancouver, ISO, and other styles

14

Seo, Bong-Chul, Witold F. Krajewski, Anton Kruger, Piotr Domaszczynski, James A. Smith, and Matthias Steiner. "Radar-rainfall estimation algorithms of Hydro-NEXRAD." Journal of Hydroinformatics 13, no. 2 (November 6, 2010): 277–91. http://dx.doi.org/10.2166/hydro.2010.003.

Full text

Abstract:

Hydro-NEXRAD is a prototype software system that provides hydrology and water resource communities with ready access to the vast data archives of the U.S. weather radar network known as NEXRAD (Next Generation Weather Radar). This paper describes radar-rainfall estimation algorithms and their modular components used in the Hydro-NEXRAD system to generate rainfall products to be delivered to users. A variety of customized modules implemented in Hydro-NEXRAD perform radar-reflectivity data processing, produce radar-rainfall maps with user-requested space and time resolution, and combine multiple radar data for basins covered by multiple radars. System users can select rainfall estimation algorithms that range from simple (‘Quick Look’) to complex and computing-intensive (‘Hi-Fi’). The ‘Pseudo NWS PPS’ option allows close comparison with the algorithm used operationally by the US National Weather Service. The ‘Custom’ algorithm enables expert users to specify values for many of the parameters in the algorithm modules according to their experience and expectations. The Hydro-NEXRAD system, with its rainfall-estimation algorithms, can be used by both novice and expert users who need rainfall estimates as references or as input to their hydrologic modelling and forecasting applications

APA, Harvard, Vancouver, ISO, and other styles

15

Ogawa, T., S. Nozawa, M. Tsutsumi, N. F. Arnold, N. Nishitani, N. Sato, and A. S. Yukimatu. "Arctic and Antarctic polar mesosphere summer echoes observed with oblique incidence HF radars: analysis using simultaneous MF and VHF radar data." Annales Geophysicae 22, no. 12 (December 22, 2004): 4049–59. http://dx.doi.org/10.5194/angeo-22-4049-2004.

Full text

Abstract:

Abstract. Polar mesosphere summer echoes (PMSEs) have been well studied using vertical incidence VHF radars at northern high-latitudes. In this paper, two PMSE events detected with the oblique incidence SuperDARN HF radars at Hankasalmi, Finland (62.3° N) and Syowa Station, Antarctica (69.0° S), are analyzed, together with simultaneous VHF and medium-frequency (MF) radar data. Altitude resolutions of the HF radars in the mesosphere and the lower thermosphere are too poor to know exact PMSE altitudes. However, a comparison of Doppler velocity from the HF radar and neutral wind velocity from the MF radar shows that PMSEs at the HF band appeared at altitudes within 80-90km, which are consistent with those from previous vertical incidence HF-VHF radar results. The HF-VHF PMSE occurrences exhibit a semidiurnal behavior, as observed by other researchers. It is found that in one event, PMSEs occurred when westward semidiurnal winds with large amplitude at 85-88km altitudes attained a maximum. When the HF-VHF PMSEs were observed at distances beyond 180km from MF radar sites, the MF radars detected no appreciable signatures of echo enhancement. Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; thermospheric dynamics; waves and tides)

APA, Harvard, Vancouver, ISO, and other styles

16

Kirkwood, S., E. Belova, K. Satheesan, T. Narayana Rao, T. Rajendra Prasad, and S. Satheesh Kumar. "Fresnel scatter revisited – comparison of 50 MHz radar and radiosondes in the Arctic, the Tropics and Antarctica." Annales Geophysicae 28, no. 10 (October 29, 2010): 1993–2005. http://dx.doi.org/10.5194/angeo-28-1993-2010.

Full text

Abstract:

Abstract. High-resolution radiosondes and calibrated radars operating close to 50 MHz, are used to examine the relationship between the strength of radar scatter and refractive index gradient. Three radars are used, in Kiruna in Arctic Sweden, at Gadanki in southern India and at the Swedish/Finnish base Wasa/Aboa in Queen Maud Land, Antarctica. Calibration is accomplished using the daily variation of galactic noise measured at each site. Proportionality between radar scatter strength and the square of the mean gradient of potential refractive index, M2, is found in the upper troposphere and lower stratosphere at all three sites, confirming previously reported results from many VHF radars. If the radar scatter is interpreted as Fresnel scatter, the constant of proportionality between radar scatter and M2 is found to be the same, within the calibration uncertainties, for all three radars. The radiosondes show evidence of distinct layering with sharp gradients, extending over 10s of kilometers horizontally, but the scatter is found to be two orders of magnitude weaker than would be expected from true Fresnel scatter from such layers. Using radar reflectivities resolved to a few 100 ms, we show that this is due to strong temporal variability in the scattering conditions, possibly due to undulations of the scattering layers. The constancy of the radar scatter – M2 relationship between the different sites suggests an unexpected uniformity in these perturbations between very different regions of the globe.

APA, Harvard, Vancouver, ISO, and other styles

17

Mellett, James S. "Ground penetrating radar applications in engineering, environmental management, and geology." Journal of Applied Geophysics 33, no. 1-3 (January 1995): 157–66. http://dx.doi.org/10.1016/0926-9851(95)90038-1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Lane, John W., Frederick D. Day-Lewis, and Peter K. Joesten. "Monitoring engineered remediation with borehole radar." Leading Edge 26, no. 8 (August 2007): 1032–35. http://dx.doi.org/10.1190/1.2769561.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Lafleche, P. T., J. P. Todoeschuck, O. G. Jensen, and A. S. Judge. "Analysis of ground-probing radar data: predictive deconvolution." Canadian Geotechnical Journal 28, no. 1 (February 1, 1991): 134–39. http://dx.doi.org/10.1139/t91-014.

Full text

Abstract:

Recent advances in ground-probing radar instrumentation have allowed the collection of large volumes of digital data. Such data sets are amenable to modern data-processing techniques both to increase geological resolution and to enhance data presentation. The close similarity between ground-radar data and seismic data suggests that processing techniques that have been used in the seismic industry could be applied to radar data. As an example, a ground probing radar profile is deconvolved using the common prediction-error filter, which assumes a white power spectrum for the reflections, and a filter that assumes a spectrum proportional to spatial frequency. With the prediction-error filter we find three of four buried pipes which are not visible in the undeconvolved section; all four are found with the second filter. Key words: ground-penetrating radar, deconvolution, scaling geology, frozen-core dams, permafrost, containment dams, mill waste, Contwoyto Lake.

APA, Harvard, Vancouver, ISO, and other styles

20

Bakker, M. A. J., D. Maljers, and H. J. T. Weerts. "Ground-penetrating radar profiling on embanked floodplains." Netherlands Journal of Geosciences - Geologie en Mijnbouw 86, no. 1 (April 2007): 55–61. http://dx.doi.org/10.1017/s0016774600021314.

Full text

Abstract:

AbstractManagement of the Dutch embanked floodplains is of crucial interest in the light of a likely increase of extreme floods. One of the issues is a gradual decrease of floodwater accommodation space as a result of overbank deposition of mud and sand during floods. To address this issue, sediment deposits of an undisturbed embanked floodplain near Winssen along the river Waal were studied using ground-penetrating radar (GPR). A number of radar facies units were recognized. Boreholes were used to relate radar facies units to sedimentary facies and to determine radar velocity. The GPR groundwave is affected by differences in moisture and texture of the top layer and probably interferes with the first subsurface reflector. The architectural elements recognized in the GPR transects confirm earlier reported insights on human-influenced river behaviour. This is testified in the development of sand bars during flood regimes that are probably more widespread than previously established.

APA, Harvard, Vancouver, ISO, and other styles

21

Swarnalingam, N., W. K. Hocking, and P. S. Argall. "Radar efficiency and the calculation of decade-long PMSE backscatter cross-section for the Resolute Bay VHF radar." Annales Geophysicae 27, no. 4 (April 7, 2009): 1643–56. http://dx.doi.org/10.5194/angeo-27-1643-2009.

Full text

Abstract:

Abstract. The Resolute Bay VHF radar, located in Nunavut, Canada (75.0° N, 95.0° W) and operating at 51.5 MHz, has been used to investigate Polar Mesosphere Summer Echoes (PMSE) since 1997. PMSE are a unique form of strong coherent radar echoes, and their understanding has been a challenge to the scientific community since their discovery more than three decades ago. While other high latitude radars have recorded strong levels of PMSE activities, the Resolute Bay radar has observed relatively lower levels of PMSE strengths. In order to derive absolute measurements of PMSE strength at this site, a technique is developed to determine the radar efficiency using cosmic (sky) noise variations along with the help of a calibrated noise source. VHF radars are only rarely calibrated, but determination of efficiency is even less common. Here we emphasize the importance of efficiency for determination of cross-section measurements. The significant advantage of this method is that it can be directly applied to any MST radar system anywhere in the world as long as the sky noise variations are known. The radar efficiencies for two on-site radars at Resolute Bay are determined. PMSE backscatter cross-section is estimated, and decade-long PMSE strength variations at this location are investigated. It was noticed that the median of the backscatter cross-section distribution remains relatively unchanged, but over the years a great level of variability occurs in the high power tail of the distribution.

APA, Harvard, Vancouver, ISO, and other styles

22

Van Dam, R. L. "Internal structure and development of an aeolian river dune in The Netherlands, using 3-D interpretation of ground-penetrating radar data." Netherlands Journal of Geosciences - Geologie en Mijnbouw 81, no. 1 (March 2002): 27–37. http://dx.doi.org/10.1017/s0016774600020540.

Full text

Abstract:

AbstractGround-penetrating radar data from a regular grid are used to study the internal structure and development of a 9-m high aeolian river dune in the Dutch Rhine-Meuse delta. The purpose of this investigation was to image the internal sedimentary structures to better understand the development of these aeolian river dunes. Three radar facies can be recognised in the GPR sections. Radar facies 1 has a maximum thickness of 5 to 6 m and is characterised by dipping, parallel reflections with a maximum length of at least 20 m. The reflections from perpendicular sections, analysed using closed-loop correlation in 3-D-interpretation software, form eastward dipping (14° maximum) surfaces. Radar facies 2 is one continuous, sub-horizontal reflection. This high amplitude reflection is most probably caused by a thin organic horizon. Radar facies 3 has a thickness of 3 to 4 m and is made up of sets of short, predominantly eastward to north-eastward dipping reflections separated by rather continuous, sub-horizontal reflections. The eastward dipping surfaces in radar facies 1 are foresets of a dune that was deposited by prevailing westerly winds in the Younger Dryas, the last cold period in the Pleistocene. During the Early Holocene, an increasing vegetation cover stabilised the dune and formed a thin organic horizon. Subsequent resumption of dune forming processes led to the formation of radar facies 3 on top of the vegetated Pleistocene dune. Sedimentation by small dunes, partly eroding each other, led to sets of cross-stratification separated by bounding surfaces. The results suggest a small change in palaeo wind direction.

APA, Harvard, Vancouver, ISO, and other styles

23

Wang, Yu, chuang-sheng Wu, and Zongying Shu. "Application and Research of Geologic Radar in Groundwater Disease of Tunnel Engineering Inspection." E3S Web of Conferences 131 (2019): 01063. http://dx.doi.org/10.1051/e3sconf/201913101063.

Full text

Abstract:

As a kind of underground lineament building, the tunnel inevitably will pass through different hydrology geology in construction process and thus form a catchment corridor which usually occurs in most of tunnels. Pour water and waterlogging is a common geological disaster and the main disease both in the construction tunnels and operation tunnels. So it is urgent for us to carry through the research on the geological disaster of groundwater. The Inspecting and controlling measures against the ground water geological disaster are also needed. In this paper, Geologic Radar is applied to tunnel engineering quality inspection to detect some quality problems possibly caused by groundwater. In order to diagnose the disease degree of operation tunnels and to estimate tunnel’s security condition, this paper analyzes the causes of bugs existing behind the tunnel lining, expounds the theory and method of making non-destructive test on tunnel lining quality by using Geological Radar. By processing and analyzing field data, the following functions can be performed, such as detecting the thickness of concrete lining accurately, determining the distribution position and quantities of rebar and grid steel, searching existed cavity and uncompacted area behind the lining especially lining arch top. We also apply the method of morphology to the extraction of liner image feature. We get the liner boundary line and waterlogging area more intuitively by wavelet analysis, and find the anomalous point in the liner. It has been proved that Geologic Radar is a feasible method to inspect the structure of tunnel concrete lining. Adopting hole-drilling method to make verifications with detecting results of geological radar, the results of the two kinds of methods do not have big difference.

APA, Harvard, Vancouver, ISO, and other styles

24

Holt, J. M., and A. P. van Eyken. "Plasma convection at high latitudes using the EISCAT VHF and ESR incoherent scatter radars." Annales Geophysicae 18, no. 9 (September 30, 2000): 1088–96. http://dx.doi.org/10.1007/s00585-000-1088-5.

Full text

Abstract:

Abstract. The recent availability of substantial data sets taken by the EISCAT Svalbard Radar allows several important tests to be made on the determination of convection patterns from incoherent scatter radar results. During one 30-h period, the Svalbard Radar made 15 min scans combining local field aligned observations with two, low elevation positions selected to intersect the two beams of the Common Programme Four experiment being simultaneously conducted by the EISCAT VHF radar at Tromsø. The common volume results from the two radars are compared. The plasma convection velocities determined independently by the two radars are shown to agree very closely and the combined three-dimensional velocity data used to test the common assumption of negligible field-aligned flow in this regime.Key words: Ionosphere (auroral ionosphere; polar ionosphere) - Magnetospheric physics (plasma convection)

APA, Harvard, Vancouver, ISO, and other styles

25

Huang, Yun Yan, Ning Han, Hong Xiang Wang, and Zhao Ling Wang. "Ground Penetrating Radar Technology and its Application in Civil Engineering." Applied Mechanics and Materials 551 (May 2014): 389–92. http://dx.doi.org/10.4028/www.scientific.net/amm.551.389.

Full text

Abstract:

The master has more detailed and accurate geological data for the exploration work effectively guiding the design and construction of great significance. Ground Penetrating Radar is a high resolution in geological exploration technology, it can explore fault zone, fractured zone, rich with water, rock caves and other abnormal geological disasters have significant effects of exploration, through a careful analysis of radar images, and we can get more reliable information on the geology.

APA, Harvard, Vancouver, ISO, and other styles

26

Guardiola-Albert, Carolina, Carlos Rivero-Honegger, Robert Monjo, Andrés Díez-Herrero, Carlos Yagüe, Jose María Bodoque, and Francisco J. Tapiador. "Automated convective and stratiform precipitation estimation in a small mountainous catchment using X-band radar data in Central Spain." Journal of Hydroinformatics 19, no. 2 (November 29, 2016): 315–30. http://dx.doi.org/10.2166/hydro.2016.225.

Full text

Abstract:

For the purposes of weather nowcasting, flood risk monitoring and water resources assessment, it is often difficult to achieve a reliable spatio-temporal representation of rainfall due to a low rain gauge network density. However, quantitative precipitation estimation (QPE) has acquired new prospects with the introduction of weather radars, thanks to their higher spatio-temporal resolution. Although a wide number of QPE algorithms are available for using C-band radar data, only a few studies have employed X-band radar. In this study the microscale rainfall variability in a small catchment is automatically measured using short-range X-band radar variograms and classifying precipitation into convective and stratiform types with a recently published index. The aim is to apply a straightforward geostatistical algorithm, named ordinary kriging of radar errors (OKRE), to integrate X-band radar and rain gauge measurements in a mountainous catchment (15 km2) in central Spain. As expected, convective events presented higher estimation errors due to their complex spatial and temporal variability. Despite this fact, errors are sufficiently small and results are reliable rainfall estimations. The two main contributions of this work are the adaptation of the OKRE method to small spatial scales and its application automatically differentiating between convective and stratiform events.

APA, Harvard, Vancouver, ISO, and other styles

27

Spargo, Andrew J., Iain M. Reid, Andrew D. MacKinnon, and David A. Holdsworth. "Mesospheric gravity wave momentum flux estimation using hybrid Doppler interferometry." Annales Geophysicae 35, no. 3 (June 12, 2017): 733–50. http://dx.doi.org/10.5194/angeo-35-733-2017.

Full text

Abstract:

Abstract. Mesospheric gravity wave (GW) momentum flux estimates using data from multibeam Buckland Park MF radar (34.6° S, 138.5° E) experiments (conducted from July 1997 to June 1998) are presented. On transmission, five Doppler beams were symmetrically steered about the zenith (one zenith beam and four off-zenith beams in the cardinal directions). The received beams were analysed with hybrid Doppler interferometry (HDI) (Holdsworth and Reid, 1998), principally to determine the radial velocities of the effective scattering centres illuminated by the radar. The methodology of Thorsen et al. (1997), later re-introduced by Hocking (2005) and since extensively applied to meteor radar returns, was used to estimate components of Reynolds stress due to propagating GWs and/or turbulence in the radar resolution volume. Physically reasonable momentum flux estimates are derived from the Reynolds stress components, which are also verified using a simple radar model incorporating GW-induced wind perturbations. On the basis of these results, we recommend the intercomparison of momentum flux estimates between co-located meteor radars and vertical-beam interferometric MF radars. It is envisaged that such intercomparisons will assist with the clarification of recent concerns (e.g. Vincent et al., 2010) of the accuracy of the meteor radar technique.

APA, Harvard, Vancouver, ISO, and other styles

28

Ogawa, T. "Radar observations of ionospheric irregularities at Syowa Station, Antarctica: a brief overview." Annales Geophysicae 14, no. 12 (December 31, 1996): 1454–61. http://dx.doi.org/10.1007/s00585-996-1454-z.

Full text

Abstract:

Abstract. We briefly overview the radar observations that have been made for 30 years at Syowa Station, Antarctica for studying small-scale electron-density irregularities in the southern high-latitude E- and F-region ionosphere. Some observational results (i.e., long-term variations of radio aurora, Doppler spectra with narrow spectral widths and low Doppler velocities, and simultaneous observations of radar and optical auroras) from VHF radars capable of detecting 1.3- to 3-m scale irregularities are presented. A new 50-MHz radar system equipped with phased-antenna arrays began operation in February 1995 to observe two-dimensional behaviours of E-region irregularities. An HF radar experiment also began in February 1995 to explore decameter-scale E- and F-region irregularities in the auroral zone and polar cap. These two radars will contribute to a better understanding of the ionospheric irregularities and ionospheric physics at southern high latitudes.

APA, Harvard, Vancouver, ISO, and other styles

29

Lester, M., P. J. Chapman, S. W. H. Cowley, S. J. Crooks, J. A. Davies, P. Hamadyk, K. A. McWilliams, et al. "Stereo CUTLASS - A new capability for the SuperDARN HF radars." Annales Geophysicae 22, no. 2 (January 1, 2004): 459–73. http://dx.doi.org/10.5194/angeo-22-459-2004.

Full text

Abstract:

Abstract. The Super Dual Auroral Radar Network (SuperDARN), which consists of networks of HF radars surrounding the northern and southern poles, has proven to be an extremely successful experimental technique in a wide range of scientific areas. The basic design of the radars, which contributes to SuperDARN, has remained virtually unchanged since the first radar was built in the early 1980s. This paper presents the first results of a significant new development of the basic system. Termed "Stereo", this development involves the addition of a duplicate receive channel and makes use of the spare duty cycle available in the current transmitters. The Stereo system has been implemented on the two radars that form the Co-operative UK Twin Located Auroral Sounding System (CUTLASS), which are the easternmost pair of radars in the Northern Hemisphere SuperDARN chain. Instead of the standard 7 pulse sequence normally employed by the radars, two such pulse sequences are interleaved and transmitted at different frequencies separated by more than 15kHz. This development allows for the radar to run two entirely different experimental modes simultaneously. Here we describe the basic Stereo system and some of the early results. We also identify potential new experiments which could be run with Stereo to complement the existing standard SuperDARN radar. Key words. Ionosphere (ionosphere-magnetosphere interactions; ionospheric irregularities; instruments and techniques)

APA, Harvard, Vancouver, ISO, and other styles

30

Grydeland, T., F. D. Lind, P. J. Erickson, and J. M. Holt. "Software Radar signal processing." Annales Geophysicae 23, no. 1 (January 31, 2005): 109–21. http://dx.doi.org/10.5194/angeo-23-109-2005.

Full text

Abstract:

Abstract. Software infrastructure is a growing part of modern radio science systems. As part of developing a generic infrastructure for implementing Software Radar systems, we have developed a set of reusable signal processing components. These components are generic software-based implementations for use on general purpose computing systems. The components allow for the implementation of signal processing chains for radio frequency signal reception, correlation-based data processing, and cross-correlation-based interferometry. The components have been used to implement the signal processing necessary for incoherent scatter radar signal reception and processing as part of the latest version of the Millstone Hill Data Acquisition System (MIDAS-W). Several hardware realizations with varying capabilities have been created, and these have been used successfully with different radars. We discuss the signal processing components in detail, describe the software patterns in which they are used, and show example data from the Millstone Hill, EISCAT Svalbard, and SOUSY Svalbard radars.

APA, Harvard, Vancouver, ISO, and other styles

31

Lemmetyinen, Juha, Anna Kontu, Jouni Pulliainen, Juho Vehviläinen, Kimmo Rautiainen, Andreas Wiesmann, Christian Mätzler, et al. "Nordic Snow Radar Experiment." Geoscientific Instrumentation, Methods and Data Systems 5, no. 2 (September 7, 2016): 403–15. http://dx.doi.org/10.5194/gi-5-403-2016.

Full text

Abstract:

Abstract. The objective of the Nordic Snow Radar Experiment (NoSREx) campaign was to provide a continuous time series of active and passive microwave observations of snow cover at a representative location of the Arctic boreal forest area, covering a whole winter season. The activity was a part of Phase A studies for the ESA Earth Explorer 7 candidate mission CoReH2O (Cold Regions Hydrology High-resolution Observatory). The NoSREx campaign, conducted at the Finnish Meteorological Institute Arctic Research Centre (FMI-ARC) in Sodankylä, Finland, hosted a frequency scanning scatterometer operating at frequencies from X- to Ku-band. The radar observations were complemented by a microwave dual-polarization radiometer system operating from X- to W-bands. In situ measurements consisted of manual snow pit measurements at the main test site as well as extensive automated measurements on snow, ground and meteorological parameters. This study provides a summary of the obtained data, detailing measurement protocols for each microwave instrument and in situ reference data. A first analysis of the microwave signatures against snow parameters is given, also comparing observed radar backscattering and microwave emission to predictions of an active/passive forward model. All data, including the raw data observations, are available for research purposes through the European Space Agency and the Finnish Meteorological Institute. A consolidated dataset of observations, comprising the key microwave and in situ observations, is provided through the ESA campaign data portal to enable easy access to the data.

APA, Harvard, Vancouver, ISO, and other styles

32

Turner, G., R. J. Yelf, and P. J. Hatherly. "Coal mining applications of ground radar." Exploration Geophysics 20, no. 2 (1989): 165. http://dx.doi.org/10.1071/eg989165.

Full text

Abstract:

Coal due to its low conductivity and high electromagnetic contrast with surrounding rocks is an attractive medium for study by ground radar. Results of trials in Australian coal mines show that ground radar can be a useful tool for horizon control, locating old underground workings and mapping geological structure both from the surface and within mine roadways.

APA, Harvard, Vancouver, ISO, and other styles

33

Collis, P. N., and M. T. Rietveld. "Mesospheric observations with the EISCAT UHF radar during polar cap absorption events: 3. Comparison with simultaneous EISCAT VHF measurements." Annales Geophysicae 16, no. 10 (October 31, 1998): 1355–66. http://dx.doi.org/10.1007/s00585-998-1355-4.

Full text

Abstract:

Abstract. Mesospheric observations were obtained by the EISCAT UHF and VHF radars during the solar proton event of March 1990. We present the first comparison of incoherent-scatter spectral measurements from the middle mesosphere using simultaneous, co-located observations by the two radars. VHF spectra observed with a vertical antenna were found to be significantly narrower than model predictions, in agreement with earlier UHF results. For antenna pointing directions that were significantly away from the vertical, the wider VHF radar beam gave rise to broadening of the observed spectra due to vertical shears in the horizontal wind. In this configuration, UHF spectral measurements were found to be more suitable for aeronomical applications. Both radar systems provide consistent and reliable estimates of the neutral wind. Spectral results using both the multipulse and pulse-to-pulse schemes were intercompared and their suitability for application to combined mesosphere – lower thermosphere studies investigated.Key words. Mesophere · Lower thermosphere · EISCAT UHF radar · EISCAT VHF radar

APA, Harvard, Vancouver, ISO, and other styles

34

Senske, D. A. "Geology of the Venus equatorial region from Pioneer Venus radar imaging." Earth, Moon and Planets 50-51, no. 1 (1990): 305–27. http://dx.doi.org/10.1007/bf00142397.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Siggins, A. F. "Ground Penetrating Radar in Geotechnical Applications." Exploration Geophysics 21, no. 3-4 (September 1, 1990): 175–86. http://dx.doi.org/10.1071/eg990175.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Davies, J. A., M. Lester, S. E. Milan, and T. K. Yeoman. "A comparison of velocity measurements from the CUTLASS Finland radar and the EISCAT UHF system." Annales Geophysicae 17, no. 7 (July 31, 1999): 892–902. http://dx.doi.org/10.1007/s00585-999-0892-9.

Full text

Abstract:

Abstract. The CUTLASS Finland radar, which comprises an integral part of the SuperDARN system of HF coherent radars, provides near continuous observations of high-latitude plasma irregularities within a field-of-view which extends over some four million square kilometres. Within the Finland radar field-of-view lie both the EISCAT mainland and EISCAT Svalbard incoherent scatter radar facilities. Since the CUTLASS Finland radar commenced operation, in February 1995, the mainland EISCAT UHF radar has been run in common programme 1 and 2 modes for a total duration exceeding 1000 h. Simultaneous and spatially coincident returns from these two radars over this period provide the basis for a comparison of irregularity drift velocity and F-region ion velocity. Initial comparison is limited to velocities from four intervals of simultaneous radar returns; intervals are selected such that they exhibit a variety of velocity signatures including that characteristic of the convection reversal and a rapidly fluctuating velocity feature. Subsequent comparison is on a statistical basis. The velocities measured by the two systems demonstrate reasonable correspondence over the velocity regime encountered during the simultaneous occurrence of coherent and incoherent scatter; differences between the EISCAT UHF measurements of F-region ion drift and the irregularity drift velocities from the Finland radar are explained in terms of a number of contributing factors including contamination of the latter by E-region echoes, a factor which is investigated further, and the potentially deleterious effect of discrepant volume and time sampling intervals.Key words. Ionosphere (ionospheric irregularities; plasma convection)

APA, Harvard, Vancouver, ISO, and other styles

37

Engler, N., W. Singer, R. Latteck, and B. Strelnikov. "Comparison of wind measurements in the troposphere and mesosphere by VHF/MF radars and in-situ techniques." Annales Geophysicae 26, no. 12 (November 24, 2008): 3693–705. http://dx.doi.org/10.5194/angeo-26-3693-2008.

Full text

Abstract:

Abstract. Radar wind observations at frequencies between 1.98 and 53.5 MHz obtained at polar latitudes were compared to in-situ wind measurements by radiosondes at tropospheric altitudes and to winds from falling spheres at mesospheric altitudes. Comparisons are shown for several campaigns of radiosonde and falling sphere observations. The radar wind directions agree well to the radiosonde and falling sphere observations and are highly correlated. The winds estimated from radar measurements are less than the radiosonde data by about 15% for spaced antenna observations and by about 10% for the Doppler beam swinging experiment. At mesospheric altitudes the spaced antenna winds obtained from the wide-beam Andenes MF radar are underestimated in the order of 35% and winds from the narrow-beam Saura MF radar are underestimated by about 20% compared to falling sphere winds at altitudes between 70 and 80 km. Furthermore, the relation between wind measurements using narrow-beam and wide-beam antenna arrangements for the MF radars is discussed and VHF radar observations are compared to the wide-beam MF radar.

APA, Harvard, Vancouver, ISO, and other styles

38

Belova, E., S. Kirkwood, J. Ekeberg, A. Osepian, I. Häggström, H. Nilsson, and M. Rietveld. "The dynamical background of polar mesosphere winter echoes from simultaneous EISCAT and ESRAD observations." Annales Geophysicae 23, no. 4 (June 3, 2005): 1239–47. http://dx.doi.org/10.5194/angeo-23-1239-2005.

Full text

Abstract:

Abstract. On 30 October 2004 during a strong solar proton event, layers of enhanced backscatter from altitudes between 55 and 75km have been observed by both ESRAD (52MHz) and the EISCAT VHF (224MHz) radars. These echoes have earlier been termed Polar Mesosphere Winter Echoes, PMWE. After considering the morphology of the layers and their relation to observed atmospheric waves, we conclude that the radars have likely seen the same phenomenon even though the radars' scattering volumes are located about 220km apart and that the most long-lasting layer is likely associated with wind-shear in an inertio-gravity wave. An ion-chemistry model is used to determine parameters necessary to relate wind-shear induced turbulent energy dissipation rates to radar backscatter. The model is verified by comparison with electron density profiles measured by the EISCAT VHF radar. Observed radar signal strengths are found to be 2-3 orders of magnitude stronger than the maximum which can be expected from neutral turbulence alone, assuming that previously published results relating radar signal scatter to turbulence parameters, and turbulence parameters to wind shear, are correct. The possibility remains that some additional or alternative mechanism may be involved in producing PMWE, such as layers of charged dust/smoke particles or large cluster ions.

APA, Harvard, Vancouver, ISO, and other styles

39

Gaddis, Lisa R., and Peter J. Mouginis-Mark. "Mississippi River outflow patterns seen by Seasat radar." Geology 13, no. 4 (1985): 227. http://dx.doi.org/10.1130/0091-7613(1985)13<227:mropsb>2.0.co;2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Koustov, Alexander, Robert Gillies, and Peter Bankole. "Validation of Clyde River SuperDARN radar velocity measurements with the RISR-C incoherent scatter radar." Annales Geophysicae 36, no. 6 (December 14, 2018): 1657–66. http://dx.doi.org/10.5194/angeo-36-1657-2018.

Full text

Abstract:

Abstract. The study considers simultaneous plasma velocity measurements in the eastward direction carried out by the Clyde River (CLY) Super Dual Auroral Radar Network (SuperDARN) high-frequency (HF) radar and Resolute Bay (RB) incoherent scatter radar – Canada (RISR-C). The HF velocities are found to be in reasonable agreement with RISR velocities up to magnitudes of 700–800 m s−1 while, for faster flows, the HF velocity magnitudes are noticeably smaller. The eastward plasma flow component inferred from SuperDARN convection maps (constructed for the area of joint measurements with consideration of velocity data from all the radars of the network) shows the effect of smaller HF velocities more notably. We show that the differences in eastward velocities between the two instruments can be significant and prolonged for observations of strongly sheared plasma flows.

APA, Harvard, Vancouver, ISO, and other styles

41

Manson, A. H., C. E. Meek, C. M. Hall, S. Nozawa, N. J. Mitchell, D. Pancheva, W. Singer, and P. Hoffmann. "Mesopause dynamics from the scandinavian triangle of radars within the PSMOS-DATAR Project." Annales Geophysicae 22, no. 2 (January 1, 2004): 367–86. http://dx.doi.org/10.5194/angeo-22-367-2004.

Full text

Abstract:

Abstract. The "Scandinavian Triangle" is a unique trio of radars within the DATAR Project (Dynamics and Temperatures from the Arctic MLT (60–97km) region): Andenes MF radar (69°N, 16°E); Tromsø MF radar (70°N, 19°E) and Esrange "Meteor" radar (68°N, 21°E). The radar-spacings range from 125-270km, making it unique for studies of wind variability associated with small-scale waves, comparisons of large-scale waves measured over small spacings, and for comparisons of winds from different radar systems. As such it complements results from arrays having spacings of 25km and 500km that have been located near Saskatoon. Correlation analysis is used to demonstrate a speed bias (MF smaller than the Meteor) between the radar types, which varies with season and altitude. Annual climatologies for the year 2000 of mean winds, solar tides, planetary and gravity waves are presented, and show indications of significant spatial variability across the Triangle and of differences in wave characteristics from middle latitudes. Key words: Meteorology and atmospheric dynamics (middle atmosphere dynamics; waves and tides: instrument and techniques)

APA, Harvard, Vancouver, ISO, and other styles

42

Bremer, J., P. Hoffmann, A. H. Manson, C. E. Meek, R. Rüster, and W. Singer. "PMSE observations at three different frequencies in northern Europe during summer 1994." Annales Geophysicae 14, no. 12 (December 31, 1996): 1317–27. http://dx.doi.org/10.1007/s00585-996-1317-7.

Full text

Abstract:

Abstract. Simultaneous observations of polar mesosphere summer echoes (PMSE) have been carried out during summer 1994 in northern Norway using three radars on different frequencies: the ALOMAR SOUSY radar at Andenes on 53.5 MHz, the EISCAT VHF radar at Tromsø on 224 MHz and the MF radar at Tromsø on 2.78 MHz. During the common measuring period in July/August 1994, PMSE could be detected at 224 and 53.5 MHz, and there are strong hints that PMSE also occur at 2.78 MHz. Reliable correlations between hourly backscattered power values indicate that the PMSE structures have zonal extensions of more than 130 km and can be detected at very different scales (half wavelength) between 0.67 (EISCAT VHF radar) and 54 m (MF radar). Using the wind values derived by the MF radar it can be shown that the mesospheric wind field influences the structure of PMSE. The diurnal variation of PMSE is strongly connected with tidal-wind components, whereas spatial differences of PMSE can partly be explained by the mean wind field.

APA, Harvard, Vancouver, ISO, and other styles

43

Kishore, Pangaluru, Isabella Velicogna, Tyler C. Sutterley, Yara Mohajerani, Enrico Ciracì, and Gummadipudi Nagasai Madhavi. "A case study of mesospheric planetary waves observed over a three-radar network using empirical mode decomposition." Annales Geophysicae 36, no. 3 (June 21, 2018): 925–36. http://dx.doi.org/10.5194/angeo-36-925-2018.

Full text

Abstract:

Abstract. In this paper an attempt is made to study equatorial Kelvin waves using a network of three radars: Kototabang (0.204∘ S, 100.320∘ E) meteor radar, Pameungpeuk (7.646∘ S, 107.688∘ E) medium-frequency radar, and Pontianak (0.003∘ S, 109.367∘ E) medium-frequency radar. We have used the continuous data gathered from the three radars during April–May 2010. Empirical mode decomposition (EMD), Lomb–Scargle periodogram (LSP) analysis, and wavelet techniques are used to study the temporal and altitude structures of planetary waves. Here, we used a novel technique called EMD to extract the planetary waves from wind data. The planetary waves of ∼ 6.5 and ∼ 3.6 days periodicity are observed in all three radar stations with peak amplitudes of about 12 and 11 m s−1, respectively. The 3.6-day wave has an average vertical wavelength from the three radars of about 42 km. The 3.6- and 6.5-day planetary waves are particularly strong in the zonal wind component. We find that the two waves are present at the 84–94 km height region. The observed features of the 3.6- and 6.5-day waves at the three tropical-latitude stations show some correspondence with the results reported for the equatorial-latitude stations. Keywords. Electromagnetics (wave propagation) – history of geophysics (atmospheric sciences) – meteorology and atmospheric dynamics (middle atmosphere dynamics)

APA, Harvard, Vancouver, ISO, and other styles

44

Wright, D. M., J. A. Davies, T. R. Robinson, P. J. Chapman, T. K. Yeoman, E. C. Thomas, M. Lester, et al. "Space Plasma Exploration by Active Radar (SPEAR): an overview of a future radar facility." Annales Geophysicae 18, no. 9 (September 30, 2000): 1248–55. http://dx.doi.org/10.1007/s00585-000-1248-7.

Full text

Abstract:

Abstract. SPEAR is a new polar cap HF radar facility which is to be deployed on Svalbard. The principal capabilities of SPEAR will include the generation of artificial plasma irregularities, operation as an 'all-sky' HF radar, the excitation of ULF waves, and remote sounding of the magnetosphere. Operation of SPEAR in conjunction with the multitude of other instruments on Svalbard, including the EISCAT Svalbard radar, and the overlap of its extensive field-of-view with that of several of the HF radars in the SuperDARN network, will enable in-depth diagnosis of many geophysical and plasma phenomena associated with the cusp region and the substorm expansion phase. Moreover, its ability to produce artificial radar aurora will provide a means for the other instruments to undertake polar cap plasma physics experiments in a controlled manner. Another potential use of the facility is in 'field-line tagging' experiments, for coordinated ground-satellite experiments. Here the scientific objectives of SPEAR are detailed, along with the proposed technical specifications of the system.Key words: Ionosphere (active experiments) – Radio science (instruments and techniques) – Space plasma physics (instruments and techniques)

APA, Harvard, Vancouver, ISO, and other styles

45

Borecka, A., J. Herzig, and M. Durjasz-Rybacka. "Ground Penetrating Radar Investigations of Landslides: A Case Study in a Landslide in Radziszów." Studia Geotechnica et Mechanica 37, no. 3 (September 1, 2015): 11–18. http://dx.doi.org/10.1515/sgem-2015-0028.

Full text

Abstract:

Abstract The article presents the results of research of the activated landslide in Radziszów in 2010. The study focused on the evaluation of engineering geology conditions, preceded by geophysical surveys. It mainly focused on the GPR method using the IDS georadar equipped with antennas in the frequency range of 100 MHz. Antenna selection was based on archival research which showed that the depth of occurrence of clays, where the roof can be a potential slip surface, ranges between 3-10 m below the surface. GPR method applied allowed the course of the potential slip surface to be determined and the results obtained significantly correlated with the results of engineering geology tests carried out.

APA, Harvard, Vancouver, ISO, and other styles

46

Plattner, Alain M. "GPRPy: Open-source ground-penetrating radar processing and visualization software." Leading Edge 39, no. 5 (May 2020): 332–37. http://dx.doi.org/10.1190/tle39050332.1.

Full text

Abstract:

GPRPy is an open-source ground-penetrating radar software compatible with a range of ground-penetrating radar systems. Data processing and plotting can be performed by using graphical user interfaces or scripts that are generated automatically from the graphical user interfaces. This makes learning the software easy, and it enables researchers to share their scripts as part of a publication to ensure reproducible research. GPRPy enables profile data processing and visualization, velocity analysis, interpolation of 3D data cubes from profile data, and 3D interpolation for interfaces visible in multiple profiles. The software is written in Python and runs on all major operating systems.

APA, Harvard, Vancouver, ISO, and other styles

47

Senske, D. A., J. W. Head, E. R. Stofan, and D. B. Campbell. "Geology and structure of Beta Regio, Venus: Results from Arecibo Radar Imaging." Geophysical Research Letters 18, no. 6 (June 1991): 1159–62. http://dx.doi.org/10.1029/91gl01001.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Soderblom, Laurence A., Robert H. Brown, Jason M. Soderblom, Jason W. Barnes, Randolph L. Kirk, Christophe Sotin, Ralf Jaumann, et al. "The geology of Hotei Regio, Titan: Correlation of Cassini VIMS and RADAR." Icarus 204, no. 2 (December 2009): 610–18. http://dx.doi.org/10.1016/j.icarus.2009.07.033.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Ogawa, T., N. F. Arnold, S. Kirkwood, N. Nishitani, and M. Lester. "Finland HF and Esrange MST radar observations of polar mesosphere summer echoes." Annales Geophysicae 21, no. 4 (April 30, 2003): 1047–55. http://dx.doi.org/10.5194/angeo-21-1047-2003.

Full text

Abstract:

Abstract. Peculiar near range echoes observed in summer with the SuperDARN HF radar in Finland are presented. The echoes were detected at four frequencies of 9, 11, 13 and 15 MHz at slant ranges of 105–250 km for about 100 min. Interferometer measurements indicate that the echoes are returned from 80–100 km altitudes with elevation angles of 20°–60°. Echo power (< 16 dB), Doppler velocity (between –30 and + 30 ms-1) and spectral width (< 60 ms-1) fluctuate with periods of several to 20 min, perhaps due to short–period atmospheric gravity waves. When the HF radar detected the echoes, a vertical incidence MST radar, located at Esrange in Sweden (650 km north of the HF radar site), observed polar mesosphere summer echoes (PMSE) at altitudes of 80–90 km. This fact suggests that the near range HF echoes are PMSE at HF band, although both radars did not probe a common volume. With increasing radar frequency, HF echo ranges are closer to the radar site and echo power becomes weaker. Possible mechanisms to explain these features are discussed.Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; thermospheric dynamics; waves and tides; instruments and techniques)

APA, Harvard, Vancouver, ISO, and other styles

50

Qiao, Xu, Wan Jun Ji, Kai Zhu, and Feng Yang. "The Research of the Ground Penetrating Radar Wave Velocity Estimation Method Based on QR Decomposition." Applied Mechanics and Materials 522-524 (February 2014): 1197–201. http://dx.doi.org/10.4028/www.scientific.net/amm.522-524.1197.

Full text

Abstract:

Ground penetrating radar (GPR) is a kind of geophysical instruments, which has been widely applied in geology, engineering, resource, environment, military etc. The method mentioned in this paper based on QR decomposition, by solving equations to find the estimated value of the radar wave velocity. This method delivers the features of real-time, accurate, and the accuracy required is not high. It is suitable for real time estimation of GPR detection. By estimating the wave velocity, we can identify the spatial location of underground target. This method provides a convenient way for the detection of underground target.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Radar geology'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles