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Journal articles on the topic 'Retrieval'

Author: Grafiati

Published: 4 June 2021

Last updated: 25 July 2025

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1

Renno, Anas, Faisal Khateeb, Viviane Kazan, et al. "A single center experience with retrievable IVC filters." Vascular 23, no. 4 (2014): 350–57. http://dx.doi.org/10.1177/1708538114546713.

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Objective To evaluate retrievable IVC filters in our institution and assess their retrieval following a well-structured follow up program. Design Retrospective cohort study. Materials The medical records of patients implanted with retrievable IVC filters were reviewed. Methods All retrievable filter insertions between July 2007 and August 2011 at our institution were reviewed. Data was analyzed for age, gender, indication, complications, retrieval rate, and brand of filter inserted. Statistical analysis was done using SPSS software v19. Chi-square was used to compare discrete data and t-test f

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2

Rubin, Ohad, and Jonathan Berant. "Retrieval-Pretrained Transformer: Long-range Language Modeling with Self-retrieval." Transactions of the Association for Computational Linguistics 12 (2024): 1197–213. http://dx.doi.org/10.1162/tacl_a_00693.

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Abstract Retrieval-augmented language models (LMs) have received much attention recently. However, typically the retriever is not trained jointly as a native component of the LM, but added post-hoc to an already-pretrained LM, which limits the ability of the LM and the retriever to adapt to one another. In this work, we propose the Retrieval-Pretrained Transformer (RPT), an architecture and training procedure for jointly training a retrieval-augmented LM from scratch and applying it to the task of modeling long texts. Given a recently generated text chunk in a long document, the LM computes qu

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3

Jalali, Ali, Shannon Hicks-Jalali, Robert J. Sica, Alexander Haefele, and Thomas von Clarmann. "A practical information-centered technique to remove a priori information from lidar optimal-estimation-method retrievals." Atmospheric Measurement Techniques 12, no. 7 (2019): 3943–61. http://dx.doi.org/10.5194/amt-12-3943-2019.

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Abstract. Lidar retrievals of atmospheric temperature and water vapor mixing ratio profiles using the optimal estimation method (OEM) typically use a retrieval grid with a number of points larger than the number of pieces of independent information obtainable from the measurements. Consequently, retrieved geophysical quantities contain some information from their respective a priori values or profiles, which can affect the results in the higher altitudes of the temperature and water vapor profiles due to decreasing signal-to-noise ratios. The extent of this influence can be estimated using the

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4

Ramesh, K., A. P. Kesarkar, J. Bhate, M. Venkat Ratnam, and A. Jayaraman. "Adaptive neuro fuzzy inference system for profiling of the atmosphere." Atmospheric Measurement Techniques Discussions 7, no. 3 (2014): 2715–36. http://dx.doi.org/10.5194/amtd-7-2715-2014.

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Abstract. Retrieval of accurate profiles of temperature and water vapor is important for the study of atmospheric convection. However, it is challenging because of the uncertainties associated with direct measurement of atmospheric parameters during convection events using radiosonde and retrieval of remote-sensed observations from satellites. Recent developments in computational techniques motivated the use of adaptive techniques in the retrieval algorithms. In this work, we have used the Adaptive Neuro Fuzzy Inference System (ANFIS) to retrieve profiles of temperature and humidity over tropi

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Zhou, Minqiang, Bavo Langerock, Mahesh Kumar Sha, et al. "Retrieval of atmospheric CH<sub>4</sub> vertical information from ground-based FTS near-infrared spectra." Atmospheric Measurement Techniques 12, no. 11 (2019): 6125–41. http://dx.doi.org/10.5194/amt-12-6125-2019.

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Abstract. The Total Carbon Column Observing Network (TCCON) column-averaged dry air mole fraction of CH4 (XCH4) measurements have been widely used to validate satellite observations and to estimate model simulations. The GGG2014 code is the standard TCCON retrieval software used in performing a profile scaling retrieval. In order to obtain several vertical pieces of information in addition to the total column, in this study, the SFIT4 retrieval code is applied to retrieve the CH4 mole fraction vertical profile from the Fourier transform spectrometer (FTS) spectrum at six sites (Ny-Ålesund, Sod

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Lipponen, Antti, Tero Mielonen, Mikko R. A. Pitkänen, et al. "Bayesian aerosol retrieval algorithm for MODIS AOD retrieval over land." Atmospheric Measurement Techniques 11, no. 3 (2018): 1529–47. http://dx.doi.org/10.5194/amt-11-1529-2018.

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Abstract. We have developed a Bayesian aerosol retrieval (BAR) algorithm for the retrieval of aerosol optical depth (AOD) over land from the Moderate Resolution Imaging Spectroradiometer (MODIS). In the BAR algorithm, we simultaneously retrieve all dark land pixels in a granule, utilize spatial correlation models for the unknown aerosol parameters, use a statistical prior model for the surface reflectance, and take into account the uncertainties due to fixed aerosol models. The retrieved parameters are total AOD at 0.55 µm, fine-mode fraction (FMF), and surface reflectances at four different w

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7

Orscheschek, Franziska, Tilo Strobach, Torsten Schubert, and Timothy Rickard. "Two retrievals from a single cue: A bottleneck persists across episodic and semantic memory." Quarterly Journal of Experimental Psychology 72, no. 5 (2018): 1005–28. http://dx.doi.org/10.1177/1747021818776818.

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There is evidence in the literature that two retrievals from long-term memory cannot occur in parallel. To date, however, that work has explored only the case of two retrievals from newly acquired episodic memory. These studies demonstrated a retrieval bottleneck even after dual-retrieval practice. That retrieval bottleneck may be a global property of long-term memory retrieval, or it may apply only to the case of two retrievals from episodic memory. In the current experiments, we explored whether that apparent dual-retrieval bottleneck applies to the case of one retrieval from episodic memory

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8

Long, Xinwei, Zhiyuan Ma, Ermo Hua, Kaiyan Zhang, Biqing Qi, and Bowen Zhou. "Retrieval-Augmented Visual Question Answering via Built-in Autoregressive Search Engines." Proceedings of the AAAI Conference on Artificial Intelligence 39, no. 23 (2025): 24723–31. https://doi.org/10.1609/aaai.v39i23.34653.

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Retrieval-augmented generation (RAG) has emerged to address the knowledge-intensive visual question answering (VQA) task. Current methods mainly employ separate retrieval and generation modules to acquire external knowledge and generate answers, respectively. We propose ReAuSE, an alternative to the previous RAG model for the knowledge-based VQA task, which seamlessly integrates knowledge retriever into the generative multi-modal large language model, serving as a built-in search engine. Specifically, our model functions both as a generative retriever and an accurate answer generator. It not o

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9

Torabian, Saba, Zhe Chen, Beth A. Ober, and Gregory K. Shenaut. "Analogical Retrieval of Folktales: A Cross-Cultural Approach." Journal of Cognition and Culture 17, no. 3-4 (2017): 281–305. http://dx.doi.org/10.1163/15685373-12340008.

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Abstract This cross-cultural study addressed how individuals retrieve and transfer naturally learned information (i.e., folktales) from long-term memory by analogy with a previously unencountered story, concept, or problem. American and Iranian participants read target stories constructed to be analogous to folktales either familiar or unfamiliar to their culture, all having high structural familiarity and either high or low surface similarity to the source folktales. Participants reported whether targets (analogues) reminded them of any specific folktale they had learned in the past; positive

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Garrett, T. J., and C. Zhao. "Ground-based remote sensing of thin clouds in the Arctic." Atmospheric Measurement Techniques Discussions 5, no. 6 (2012): 8653–99. http://dx.doi.org/10.5194/amtd-5-8653-2012.

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Abstract. This paper describes a method for using interferometer measurements of downwelling thermal radiation to retrieve the properties of single-layer clouds. Cloud phase is determined from ratios of thermal emission in three "micro-windows" where absorption by water vapor is particularly small. Cloud microphysical and optical properties are retrieved from thermal emission in two micro-windows, constrained by the transmission through clouds of stratospheric ozone emission. Assuming a cloud does not approximate a blackbody, the estimated 95% confidence retrieval errors in effective radius, v

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Negi, H. S., and A. Kokhanovsky. "Retrieval of snow grain size and albedo of Western Himalayan snow cover using satellite data." Cryosphere Discussions 5, no. 1 (2011): 605–53. http://dx.doi.org/10.5194/tcd-5-605-2011.

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Abstract. In the present study we describe the retrievals of snow grain size and spectral albedo (plane and spherical albedo) for Western Himalayan snow cover using Hyperion sensor data. The asymptotic radiative transfer (ART) theory was explored for the snow retrievals. To make the methodology operational only five spectral bands (440, 500, 1050, 1240 and 1650 nm) of Hyperion were used for snow parameters retrieval. The bi-spectral method (440 nm in the visible and 1050/1240 nm in the NIR region) was used to retrieve snow grain size. Spectral albedos were retrieved using satellite reflectance

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Negi, H. S., and A. Kokhanovsky. "Retrieval of snow grain size and albedo of western Himalayan snow cover using satellite data." Cryosphere 5, no. 4 (2011): 831–47. http://dx.doi.org/10.5194/tc-5-831-2011.

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Abstract. In the present study we describe the retrievals of snow grain size and spectral albedo (plane and spherical albedo) for western Himalayan snow cover using Hyperion sensor data. The asymptotic radiative transfer (ART) theory was explored for the snow retrievals. To make the methodology operational only five spectral bands (440, 500, 1050, 1240 and 1650 nm) of Hyperion were used for snow parameters retrieval. The bi-spectral method (440 nm in the visible and 1050/1240 nm in the NIR region) was used to retrieve snow grain size. Spectral albedos were retrieved using satellite reflectance

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Wang, Ji, Jared R. Kolecki, Jean-Baptiste Ruffio, et al. "Retrieving the C and O Abundances of HR 7672 AB: A Solar-type Primary Star with a Benchmark Brown Dwarf." Astronomical Journal 163, no. 4 (2022): 189. http://dx.doi.org/10.3847/1538-3881/ac56e2.

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Abstract A benchmark brown dwarf (BD) is a BD whose properties (e.g., mass and chemical composition) are precisely and independently measured. Benchmark BDs are valuable in testing theoretical evolutionary tracks, spectral synthesis, and atmospheric retrievals for substellar objects. Here, we report results of atmospheric retrieval on a synthetic spectrum and a benchmark BD, HR 7672 B, with petitRADTRANS. First, we test the retrieval framework on a synthetic PHOENIX BT-Settl spectrum with a solar composition. We show that the retrieved C and O abundances are consistent with solar values, but t

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Adhikari, Loknath, Feiqin Xie, and Jennifer S. Haase. "Application of the full spectrum inversion algorithm to simulated airborne GPS radio occultation signals." Atmospheric Measurement Techniques 9, no. 10 (2016): 5077–87. http://dx.doi.org/10.5194/amt-9-5077-2016.

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Abstract. With a GPS receiver on board an airplane, the airborne radio occultation (ARO) technique provides dense lower-tropospheric soundings over target regions. Large variations in water vapor in the troposphere cause strong signal multipath, which could lead to systematic errors in RO retrievals with the geometric optics (GO) method. The spaceborne GPS RO community has successfully developed the full-spectrum inversion (FSI) technique to solve the multipath problem. This paper is the first to adapt the FSI technique to retrieve atmospheric properties (bending and refractivity) from ARO sig

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Di Noia, A., O. P. Hasekamp, G. van Harten, et al. "Use of neural networks in ground-based aerosol retrievals from multi-angle spectropolarimetric observations." Atmospheric Measurement Techniques 8, no. 1 (2015): 281–99. http://dx.doi.org/10.5194/amt-8-281-2015.

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Abstract. In this paper, the use of a neural network algorithm for the retrieval of the aerosol properties from ground-based spectropolarimetric measurements is discussed. The neural network is able to retrieve the aerosol properties with an accuracy that is almost comparable to that of an iterative retrieval. By using the outcome of the neural network as first guess in the iterative retrieval scheme, the accuracy of the retrieved fine- and coarse-mode optical thickness is further improved, while for the other parameters the improvement is small or absent. The resulting scheme (neural network

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Tokumi, Yuta, Junki Hakamata, and Masataka Tokumaru. "Development of a Nutritional Management System for a Healthy Eating Habits Support System." Journal of Advanced Computational Intelligence and Intelligent Informatics 17, no. 2 (2013): 324–34. http://dx.doi.org/10.20965/jaciii.2013.p0324.

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In this study, we propose a Nutritional Management System (NMS) that optimizes nutritional balance using a tabu search. Contemporary recipe retrieval systems generally retrieve a recipe either by using a keyword or by recommending a popular recipe. However, these recipe retrieval systems yield the same retrieval results for different users, and thus, the results do not necessarily reflect an individual user’s tastes. In addition, the search results delivered by many recipe retrieval systems do not always describe the nutritional details of the recipes. Therefore, we developed a Healthy Eating

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Frankenberg, C., O. Hasekamp, C. O'Dell, S. Sanghavi, A. Butz, and J. Worden. "Aerosol information content analysis of multi-angle high spectral resolution measurements and its benefit for high accuracy greenhouse gas retrievals." Atmospheric Measurement Techniques Discussions 5, no. 2 (2012): 2857–85. http://dx.doi.org/10.5194/amtd-5-2857-2012.

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Abstract. New generations of space-borne spectrometers for the retrieval of atmospheric abundances of greenhouse gases require unprecedented accuracies as atmospheric variability of long-lived gases is very low. These instruments, such as GOSAT and OCO-2, typically use a high spectral resolution oxygen channel (O2 A-band) in addition to CO2 and CH4 channels to discriminate changes in the photon path-length distribution from actual trace gas amount changes. Inaccurate knowledge of the photon path-length distribution, determined by scatterers in the atmosphere, is the prime source of systematic

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Frankenberg, C., O. Hasekamp, C. O'Dell, S. Sanghavi, A. Butz, and J. Worden. "Aerosol information content analysis of multi-angle high spectral resolution measurements and its benefit for high accuracy greenhouse gas retrievals." Atmospheric Measurement Techniques 5, no. 7 (2012): 1809–21. http://dx.doi.org/10.5194/amt-5-1809-2012.

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Abstract. New generations of space-borne spectrometers for the retrieval of atmospheric abundances of greenhouse gases require unprecedented accuracies as atmospheric variability of long-lived gases is very low. These instruments, such as GOSAT and OCO-2, typically use a high spectral resolution oxygen channel (O2 A-band) in addition to CO2 and CH4 channels to discriminate changes in the photon path-length distribution from actual trace gas amount changes. Inaccurate knowledge of the photon path-length distribution, determined by scatterers in the atmosphere, is the prime source of systematic

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Friedrich, Martina Michaela, Claudia Rivera, Wolfgang Stremme, et al. "NO<sub>2</sub> vertical profiles and column densities from MAX-DOAS measurements in Mexico City." Atmospheric Measurement Techniques 12, no. 4 (2019): 2545–65. http://dx.doi.org/10.5194/amt-12-2545-2019.

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Abstract. We present a new numerical code, Mexican MAX-DOAS Fit (MMF), developed to retrieve profiles of different trace gases from the network of MAX-DOAS instruments operated in Mexico City. MMF uses differential slant column densities (dSCDs) retrieved with the QDOAS (Danckaert et al., 2013) software. The retrieval is comprised of two steps, an aerosol retrieval and a trace gas retrieval that uses the retrieved aerosol profile in the forward model for the trace gas. For forward model simulations, VLIDORT is used (e.g., Spurr et al., 2001; Spurr, 2006, 2013). Both steps use constrained least

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Grzegorski, M., M. Wenig, U. Platt, P. Stammes, N. Fournier, and T. Wagner. "The Heidelberg iterative cloud retrieval utilities (HICRU) and its application to GOME data." Atmospheric Chemistry and Physics Discussions 6, no. 2 (2006): 1637–78. http://dx.doi.org/10.5194/acpd-6-1637-2006.

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Abstract. Information about clouds, in particular the accurate identification of cloud free pixels, is crucial for the retrieval of tropospheric vertical column densities from space. The Heidelberg Iterative Cloud Retrieval Utilities (HICRU) retrieve effective cloud fraction using spectra of two instruments designed for trace gas retrievals from space: The Global Ozone Monitoring Experiment (GOME) on the European Remote Sensing Satellite (ERS-2) and the SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) on ENVISAT. HICRU applies the widely used threshold method t

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Grzegorski, M., M. Wenig, U. Platt, P. Stammes, N. Fournier, and T. Wagner. "The Heidelberg iterative cloud retrieval utilities (HICRU) and its application to GOME data." Atmospheric Chemistry and Physics 6, no. 12 (2006): 4461–76. http://dx.doi.org/10.5194/acp-6-4461-2006.

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Abstract. Information about clouds, in particular the accurate identification of cloud free pixels, is crucial for the retrieval of tropospheric vertical column densities from space. The Heidelberg Iterative Cloud Retrieval Utilities (HICRU) retrieve effective cloud fraction using spectra of two instruments designed for trace gas retrievals from space: The Global Ozone Monitoring Experiment (GOME) on the European Remote Sensing Satellite (ERS-2) and the SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) on ENVISAT. HICRU applies the widely used threshold method t

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Jeong, U., J. Kim, C. Ahn, et al. "An online aerosol retrieval algorithm using OMI near-UV observations based on the optimal estimation method." Atmospheric Chemistry and Physics Discussions 15, no. 12 (2015): 16615–54. http://dx.doi.org/10.5194/acpd-15-16615-2015.

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Abstract. An online version of the OMI (Ozone Monitoring Instrument) near-ultraviolet (UV) aerosol retrieval algorithm was developed to retrieve aerosol optical thickness (AOT) and single scattering albedo (SSA) based on the optimal estimation (OE) method. Instead of using the traditional look-up tables for radiative transfer calculations, it performs online radiative transfer calculations with the Vector Linearized Discrete Ordinate Radiative Transfer (VLIDORT) model to eliminate interpolation errors and improve stability. The OE-based algorithm has the merit of providing useful estimates of

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Nadel, Lynn, Jenna Campbell, and Lee Ryan. "Autobiographical Memory Retrieval and Hippocampal Activation as a Function of Repetition and the Passage of Time." Neural Plasticity 2007 (2007): 1–14. http://dx.doi.org/10.1155/2007/90472.

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Multiple trace theory (MTT) predicts that hippocampal memory traces expand and strengthen as a function of repeated memory retrievals. We tested this hypothesis utilizing fMRI, comparing the effect of memory retrieval versus the mere passage of time on hippocampal activation. While undergoing fMRI scanning, participants retrieved remote autobiographical memories that had been previously retrieved either one month earlier, two days earlier, or multiple times during the preceding month. Behavioral analyses revealed that the number and consistency of memory details retrieved increased with multip

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Garrett, T. J., and C. Zhao. "Ground-based remote sensing of thin clouds in the Arctic." Atmospheric Measurement Techniques 6, no. 5 (2013): 1227–43. http://dx.doi.org/10.5194/amt-6-1227-2013.

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Abstract. This paper describes a method for using interferometer measurements of downwelling thermal radiation to retrieve the properties of single-layer clouds. Cloud phase is determined from ratios of thermal emission in three "micro-windows" at 862.5 cm−1, 935.8 cm−1, and 988.4 cm−1 where absorption by water vapour is particularly small. Cloud microphysical and optical properties are retrieved from thermal emission in the first two of these micro-windows, constrained by the transmission through clouds of primarily stratospheric ozone emission at 1040 cm−1. Assuming a cloud does not approxim

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Stein, Thorwald H. M., Julien Delanoë, and Robin J. Hogan. "A Comparison among Four Different Retrieval Methods for Ice-Cloud Properties Using Data from CloudSat, CALIPSO, and MODIS." Journal of Applied Meteorology and Climatology 50, no. 9 (2011): 1952–69. http://dx.doi.org/10.1175/2011jamc2646.1.

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AbstractThe A-Train constellation of satellites provides a new capability to measure vertical cloud profiles that leads to more detailed information on ice-cloud microphysical properties than has been possible up to now. A variational radar–lidar ice-cloud retrieval algorithm (VarCloud) takes advantage of the complementary nature of the CloudSat radar and Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) lidar to provide a seamless retrieval of ice water content, effective radius, and extinction coefficient from the thinnest cirrus (seen only by the lidar) to the thi

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Ramesh, K., A. P. Kesarkar, J. Bhate, M. Venkat Ratnam, and A. Jayaraman. "Adaptive neuro-fuzzy inference system for temperature and humidity profile retrieval from microwave radiometer observations." Atmospheric Measurement Techniques 8, no. 1 (2015): 369–84. http://dx.doi.org/10.5194/amt-8-369-2015.

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Abstract. The retrieval of accurate profiles of temperature and water vapour is important for the study of atmospheric convection. Recent development in computational techniques motivated us to use adaptive techniques in the retrieval algorithms. In this work, we have used an adaptive neuro-fuzzy inference system (ANFIS) to retrieve profiles of temperature and humidity up to 10 km over the tropical station Gadanki (13.5° N, 79.2° E), India. ANFIS is trained by using observations of temperature and humidity measurements by co-located Meisei GPS radiosonde (henceforth referred to as radiosonde)

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Matrosov, Sergey Y. "Attenuation-Based Estimates of Rainfall Rates Aloft with Vertically Pointing Ka-Band Radars." Journal of Atmospheric and Oceanic Technology 22, no. 1 (2005): 43–54. http://dx.doi.org/10.1175/jtech-1677.1.

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Abstract An approach is suggested to retrieve low-resolution rainfall rate profiles and layer-averaged rainfall rates, Ra, from radar reflectivity measurements made by vertically pointing Ka-band radars. This approach is based on the effects of attenuation of radar signals in rain and takes advantage of the nearly linear relation between specific attenuation and rainfall rate at Ka-band frequencies. The variability of this relation due to temperature, details of raindrop size distributions, and the nature of rain (convective versus stratiform) is rather small (∼10%) and contributes little to e

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Loveridge, Jesse, Aviad Levis, Larry Di Girolamo, et al. "Retrieving 3D distributions of atmospheric particles using Atmospheric Tomography with 3D Radiative Transfer – Part 2: Local optimization." Atmospheric Measurement Techniques 16, no. 16 (2023): 3931–57. http://dx.doi.org/10.5194/amt-16-3931-2023.

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Abstract. Our global understanding of clouds and aerosols relies on the remote sensing of their optical, microphysical, and macrophysical properties using, in part, scattered solar radiation. Current retrievals assume clouds and aerosols form plane-parallel, homogeneous layers and utilize 1D radiative transfer (RT) models. These assumptions limit the detail that can be retrieved about the 3D variability in the cloud and aerosol fields and induce biases in the retrieved properties for highly heterogeneous structures such as cumulus clouds and smoke plumes. In Part 1 of this two-part study, we v

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van Diedenhoven, B., O. P. Hasekamp, and I. Aben. "Surface pressure retrieval from SCIAMACHY measurements in the O<sub>2</sub>A Band: validation of the measurements and sensitivity on aerosols." Atmospheric Chemistry and Physics Discussions 5, no. 2 (2005): 1469–99. http://dx.doi.org/10.5194/acpd-5-1469-2005.

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Abstract. We perform surface pressure retrievals from cloud-free Oxygen A band measurements of SCIAMACHY. These retrievals can be well validated because surface pressure is a quantity that is, in general, accurately known from meteorological models. Therefore, surface 5 pressure retrievals and their validation provide important insight into the quality of the instrument calibration. Furthermore, they can provide insight into retrievals which are affected by similar radiation transport processes, for example the retrieval of total columns of H2O, CO, CO2 and CH4. In our retrieval aerosols are n

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Lin, J. T., R. V. Martin, K. F. Boersma, et al. "Retrieving tropospheric nitrogen dioxide from the Ozone Monitoring Instrument: effects of aerosols, surface reflectance anisotropy, and vertical profile of nitrogen dioxide." Atmospheric Chemistry and Physics 14, no. 3 (2014): 1441–61. http://dx.doi.org/10.5194/acp-14-1441-2014.

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Abstract. Retrievals of tropospheric nitrogen dioxide (NO2) from the Ozone Monitoring Instrument (OMI) are subject to errors in the treatments of aerosols, surface reflectance anisotropy, and vertical profile of NO2. Here we quantify the influences over China via an improved retrieval process. We explicitly account for aerosol optical effects (simulated by nested GEOS-Chem at 0.667° long. × 0.5° lat. and constrained by aerosol measurements), surface reflectance anisotropy, and high-resolution vertical profiles of NO2 (simulated by GEOS-Chem). Prior to the NO2 retrieval, we derive the cloud inf

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van Diedenhoven, B., O. P. Hasekamp, and I. Aben. "Surface pressure retrieval from SCIAMACHY measurements in the O<sub>2</sub> A Band: validation of the measurements and sensitivity on aerosols." Atmospheric Chemistry and Physics 5, no. 8 (2005): 2109–20. http://dx.doi.org/10.5194/acp-5-2109-2005.

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Abstract. We perform surface pressure retrievals from cloud-free Oxygen A band measurements of SCIAMACHY. These retrievals can be well validated because surface pressure is a quantity that is, in general, accurately known from meteorological models. Therefore, surface pressure retrievals and their validation provide important insight into the quality of the instrument calibration. Furthermore, they can provide insight into retrievals which are affected by similar radiation transport processes, for example the retrieval of total columns of H2O, CO, CO2 and CH4. In our retrieval aerosols are neg

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Lin, J. T., R. V. Martin, K. F. Boersma, et al. "Retrieving tropospheric nitrogen dioxide over China from the Ozone Monitoring Instrument: effects of aerosols, surface reflectance anisotropy and vertical profile of nitrogen dioxide." Atmospheric Chemistry and Physics Discussions 13, no. 8 (2013): 21203–57. http://dx.doi.org/10.5194/acpd-13-21203-2013.

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Abstract. Retrievals of tropospheric nitrogen dioxide (NO2) from the Ozone Monitoring Instrument (OMI) are subject to errors in the treatments of aerosols, surface reflectance anisotropy, and vertical profile of NO2. Here we quantify the influences over China via an improved retrieval process. We explicitly account for aerosol optical effects (simulated by nested GEOS-Chem at 0.667° lon × 0.5° lat and constrained by aerosol measurements), surface reflectance anisotropy, and high-resolution vertical profiles of NO2 (simulated by GEOS-Chem). Prior to the NO2 retrieval, we derive the cloud inform

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Kwon, Eun-Han, B. J. Sohn, William L. Smith, and Jun Li. "Validating IASI Temperature and Moisture Sounding Retrievals over East Asia Using Radiosonde Observations." Journal of Atmospheric and Oceanic Technology 29, no. 9 (2012): 1250–62. http://dx.doi.org/10.1175/jtech-d-11-00078.1.

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Abstract Temperature and moisture profiles retrieved from Infrared Atmospheric Sounding Interferometer (IASI) data are evaluated using collocated radiosonde data from September 2008 to August 2009 over East Asia. The level-2 products used in this study were provided by the National Oceanic and Atmospheric Administration/National Environmental Satellite, Data, and Information Service. By using radiosonde observations as a reference, the bias and root-mean-square error (RMSE) of the temperature and water vapor profiles are obtained to examine the performance of the IASI retrievals depending on s

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Strong, K., B. M. Joseph, R. Dosanjh, et al. "Retrieval of vertical concentration profiles from OSIRIS UVvisible limb spectra." Canadian Journal of Physics 80, no. 4 (2002): 409–34. http://dx.doi.org/10.1139/p01-153.

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The OSIRIS instrument, launched on the Odin satellite in February 2001, includes an optical spectrograph that will record UVvisible spectra of sunlight scattered from the limb over a range of tangent heights. These spectra will be used to retrieve vertical profiles of ozone, NO2, OClO, BrO, NO3, O2, and aerosols, for the investigation of both stratospheric and mesospheric processes, particularly those related to ozone chemistry. In this work, the retrieval of vertical profiles of trace-gas concentrations from OSIRIS limb-radiance spectra is described. A forward model has been developed to sim

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Li, Dingdong, Yonghua Wu, Barry Gross, and Fred Moshary. "Capabilities of an Automatic Lidar Ceilometer to Retrieve Aerosol Characteristics within the Planetary Boundary Layer." Remote Sensing 13, no. 18 (2021): 3626. http://dx.doi.org/10.3390/rs13183626.

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Continuous observation and quantitative retrieval of aerosol backscatter coefficients are important in the study of air quality and climate in metropolitan areas such as New York City. Ceilometers are ideal for this application, but aerosol backscatter coefficient retrievals from ceilometers are challenging and require proper calibration. In this study, we calibrate the ceilometer (Lufft CHM15k, 1064 nm) system constant with the molecular backscatter coefficient and evaluate the calibrated profiles with other independent methods, including the water-phase cloud method and comparison with the N

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Zheng, Jianyu, Zhibo Zhang, Hongbin Yu, et al. "Thermal infrared dust optical depth and coarse-mode effective diameter over oceans retrieved from collocated MODIS and CALIOP observations." Atmospheric Chemistry and Physics 23, no. 14 (2023): 8271–304. http://dx.doi.org/10.5194/acp-23-8271-2023.

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Abstract. In this study, we developed a novel algorithm based on the collocated Moderate Resolution Imaging Spectroradiometer (MODIS) thermal infrared (TIR) observations and dust vertical profiles from the Cloud–Aerosol Lidar with Orthogonal Polarization (CALIOP) to simultaneously retrieve dust aerosol optical depth at 10 µm (DAOD10 µm) and the coarse-mode dust effective diameter (Deff) over global oceans. The accuracy of the Deff retrieval is assessed by comparing the dust lognormal volume particle size distribution (PSD) corresponding to retrieved Deff with the in situ-measured dust PSDs fro

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Shi, Chong, Makiko Hashimoto, and Teruyuki Nakajima. "Remote sensing of aerosol properties from multi-wavelength and multi-pixel information over the ocean." Atmospheric Chemistry and Physics 19, no. 4 (2019): 2461–75. http://dx.doi.org/10.5194/acp-19-2461-2019.

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Abstract. In this study, we investigate the feasibility of a multi-pixel scheme in the inversion of aerosol optical properties for multispectral satellite instruments over the ocean. Different from the traditional satellite aerosol retrievals conducted pixel by pixel, we derive the aerosol optical thickness (AOT) of multiple pixels simultaneously by adding a smoothness constraint on the spatial variation of aerosols and oceanic substances, which helps the satellite retrieval, with higher consistency from pixel to pixel. Simulations are performed for two representative oceanic circumstances, op

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Cha, Ting-Yu, and Michael M. Bell. "Comparison of single-Doppler and multiple-Doppler wind retrievals in Hurricane Matthew (2016)." Atmospheric Measurement Techniques 14, no. 5 (2021): 3523–39. http://dx.doi.org/10.5194/amt-14-3523-2021.

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Abstract. Hurricane Matthew (2016) was observed by the ground-based polarimetric Next Generation Weather Radar (NEXRAD) in Miami (KAMX) and the National Oceanic and Atmospheric Administration WP-3D (NOAA P-3) airborne tail Doppler radar near the coast of the southeastern United States for several hours, providing a novel opportunity to evaluate and compare single- and multiple-Doppler wind retrieval techniques for tropical cyclone flows. The generalized velocity track display (GVTD) technique can retrieve a subset of the wind field from a single ground-based Doppler radar under the assumption

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Lu, Shijun, Ruru Deng, Yeheng Liang, Longhai Xiong, Xianjun Ai, and Yan Qin. "Remote Sensing Retrieval of Total Phosphorus in the Pearl River Channels Based on the GF-1 Remote Sensing Data." Remote Sensing 12, no. 9 (2020): 1420. http://dx.doi.org/10.3390/rs12091420.

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Total phosphorus (TP) concentration is one of the indicators for surface water quality evaluation. In this study, an indirect algorithm was proposed to retrieve TP concentration. This algorithm retrieves the TP concentration in urban waters based on Gaofen-1 (GF-1) remote sensing data. The algorithm uses the correlation between remote-sensing reflectance, optically significant constituents of water (chlorophyll, suspended sediment, and organic matter (excluding algae)), and TP to establish a retrieval model. First, the concentrations of optically active components are retrieved using a semi-an

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Dubovik, O., M. Herman, A. Holdak, et al. "Statistically optimized inversion algorithm for enhanced retrieval of aerosol properties from spectral multi-angle polarimetric satellite observations." Atmospheric Measurement Techniques Discussions 3, no. 6 (2010): 4967–5077. http://dx.doi.org/10.5194/amtd-3-4967-2010.

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Abstract. The proposed development is an attempt to enhance aerosol retrieval by emphasizing statistical optimization in inversion of advanced satellite observations. This optimization concept improves retrieval accuracy relying on the knowledge of measurement error distribution. Efficient application of such optimization requires pronounced data redundancy (excess of the measurements number over number of unknowns) that is not common in satellite observations. The POLDER imager on board of the PARASOL micro-satellite registers spectral polarimetric characteristics of the reflected atmospheric

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Dubovik, O., M. Herman, A. Holdak, et al. "Statistically optimized inversion algorithm for enhanced retrieval of aerosol properties from spectral multi-angle polarimetric satellite observations." Atmospheric Measurement Techniques 4, no. 5 (2011): 975–1018. http://dx.doi.org/10.5194/amt-4-975-2011.

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Abstract. The proposed development is an attempt to enhance aerosol retrieval by emphasizing statistical optimization in inversion of advanced satellite observations. This optimization concept improves retrieval accuracy relying on the knowledge of measurement error distribution. Efficient application of such optimization requires pronounced data redundancy (excess of the measurements number over number of unknowns) that is not common in satellite observations. The POLDER imager on board the PARASOL micro-satellite registers spectral polarimetric characteristics of the reflected atmospheric ra

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Holz, Robert E., Steve Ackerman, Paolo Antonelli, et al. "An Improvement to the High-Spectral-Resolution CO2-Slicing Cloud-Top Altitude Retrieval." Journal of Atmospheric and Oceanic Technology 23, no. 5 (2006): 653–70. http://dx.doi.org/10.1175/jtech1877.1.

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Abstract An improvement to high-spectral-resolution infrared cloud-top altitude retrievals is compared to existing retrieval methods and cloud lidar measurements. The new method, CO2 sorting, determines optimal channel pairs to which the CO2 slicing retrieval will be applied. The new retrieval is applied to aircraft Scanning High-Resolution Interferometer Sounder (S-HIS) measurements. The results are compared to existing passive retrieval methods and coincident Cloud Physics Lidar (CPL) measurements. It is demonstrated that when CO2 sorting is used to select channel pairs for CO2 slicing there

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Löhnert, Ulrich, D. D. Turner, and S. Crewell. "Ground-Based Temperature and Humidity Profiling Using Spectral Infrared and Microwave Observations. Part I: Simulated Retrieval Performance in Clear-Sky Conditions." Journal of Applied Meteorology and Climatology 48, no. 5 (2009): 1017–32. http://dx.doi.org/10.1175/2008jamc2060.1.

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Abstract Two independent ground-based passive remote sensing methods are used to retrieve lower-tropospheric temperature and humidity profiles in clear-sky cases. A simulation study for two distinctly different climatic zones is performed to evaluate the accuracies of a standard microwave profiler [humidity and temperature profiler (HATPRO)] and an infrared spectrometer [Atmospheric Emitted Radiance Interferometer (AERI)] by applying a unified optimal estimation scheme to each instrument. Different measurement modes for each instrument are also evaluated in which the retrieval uses different s

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Torres, Benjamin, and David Fuertes. "Characterization of aerosol size properties from measurements of spectral optical depth: a global validation of the GRASP-AOD code using long-term AERONET data." Atmospheric Measurement Techniques 14, no. 6 (2021): 4471–506. http://dx.doi.org/10.5194/amt-14-4471-2021.

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Abstract. A validation study is conducted regarding aerosol optical size property retrievals from measurements of the direct sun beam only (without the aid of diffuse radiation). The study focuses on using real data to test the new GRASP-AOD application, which uses only spectral optical depth measurements to retrieve the total column aerosol size distributions, assumed to be bimodal lognormal. In addition, a set of secondary integral parameters of aerosol size distribution and optical properties are provided: effective radius, total volume concentration and fine-mode fraction of aerosol optica

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Roche, Sébastien, Kimberly Strong, Debra Wunch, et al. "Retrieval of atmospheric CO<sub>2</sub> vertical profiles from ground-based near-infrared spectra." Atmospheric Measurement Techniques 14, no. 4 (2021): 3087–118. http://dx.doi.org/10.5194/amt-14-3087-2021.

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Abstract. We evaluate vertical profile retrievals of CO2 from 0.02 cm−1 resolution ground-based near-infrared solar absorption spectra with the GFIT2 algorithm, using improved spectroscopic line lists and line shapes. With these improvements, CO2 profiles were obtained from sequential retrievals in five spectral windows with different vertical sensitivities using synthetic and real spectra. A sensitivity study using synthetic spectra shows that the leading source of uncertainty in the retrieved CO2 profiles is the error in the a priori temperature profile, even with 3-hourly reanalysis a prior

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Herrera, Milagros E., Oleg Dubovik, Benjamin Torres, et al. "Estimates of remote sensing retrieval errors by the GRASP algorithm: application to ground-based observations, concept and validation." Atmospheric Measurement Techniques 15, no. 20 (2022): 6075–126. http://dx.doi.org/10.5194/amt-15-6075-2022.

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Abstract. Understanding the uncertainties in the retrieval of aerosol and surface properties is very important for an adequate characterization of the processes that occur in the atmosphere. However, the reliable characterization of the error budget of the retrieval products is a very challenging aspect that currently remains not fully resolved in most remote sensing approaches. The level of uncertainties for the majority of the remote sensing products relies mostly on post-processing validations and intercomparisons with other data, while the dynamic errors are rarely provided. Therefore, imp

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LEE, SUH-YIN, and MAN-KWAN SHAN. "ACCESS METHODS OF IMAGE DATABASE." International Journal of Pattern Recognition and Artificial Intelligence 04, no. 01 (1990): 27–44. http://dx.doi.org/10.1142/s0218001490000034.

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The perception of spatial relationships among objects in a picture is one of the important selection criteria to discriminate and retrieve images in an image database system. The data structure called 2-D string, proposed by Chang et al., is adopted to represent the symbolic pictures. When there are a large number of images in the image database and each image contains many objects, the processing time for image retrievals is tremendous. It is essential to develop efficient access methods for these retrievals. In this paper, the efficient methods for retrieval by objects, retrieval by pairwise

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Benavent-Oltra, Jose A., Roberto Román, María J. Granados-Muñoz, et al. "Comparative assessment of GRASP algorithm for a dust event over Granada (Spain) during ChArMEx-ADRIMED 2013 campaign." Atmospheric Measurement Techniques 10, no. 11 (2017): 4439–57. http://dx.doi.org/10.5194/amt-10-4439-2017.

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Abstract. In this study, vertical profiles and column-integrated aerosol properties retrieved by the GRASP (Generalized Retrieval of Atmosphere and Surface Properties) algorithm are evaluated with in situ airborne measurements made during the ChArMEx-ADRIMED field campaign in summer 2013. In the framework of this campaign, two different flights took place over Granada (Spain) during a desert dust episode on 16 and 17 June. The GRASP algorithm, which combines lidar and sun–sky photometer data measured at Granada, was used to retrieve aerosol properties. Two sun-photometer datasets are used: one

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Leinonen, Jussi, Matthew D. Lebsock, Simone Tanelli, et al. "Retrieval of snowflake microphysical properties from multifrequency radar observations." Atmospheric Measurement Techniques 11, no. 10 (2018): 5471–88. http://dx.doi.org/10.5194/amt-11-5471-2018.

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Abstract. We have developed an algorithm that retrieves the size, number concentration and density of falling snow from multifrequency radar observations. This work builds on previous studies that have indicated that three-frequency radars can provide information on snow density, potentially improving the accuracy of snow parameter estimates. The algorithm is based on a Bayesian framework, using lookup tables mapping the measurement space to the state space, which allows fast and robust retrieval. In the forward model, we calculate the radar reflectivities using recently published snow scatter

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Karthikeyan, Lanka, Ming Pan, Dasika Nagesh Kumar, and Eric F. Wood. "Effect of Structural Uncertainty in Passive Microwave Soil Moisture Retrieval Algorithm." Sensors 20, no. 4 (2020): 1225. http://dx.doi.org/10.3390/s20041225.

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Passive microwave sensors use a radiative transfer model (RTM) to retrieve soil moisture (SM) using brightness temperatures (TB) at low microwave frequencies. Vegetation optical depth (VOD) is a key input to the RTM. Retrieval algorithms can analytically invert the RTM using dual-polarized TB measurements to retrieve the VOD and SM concurrently. Algorithms in this regard typically use the τ-ω types of models, which consist of two third-order polynomial equations and, thus, can have multiple solutions. Through this work, we find that uncertainty occurs due to the structural indeterminacy that i

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