Log in

Relevant bibliographies by topics / Sun elevation / Journal articles

To see the other types of publications on this topic, follow the link: Sun elevation.

Journal articles on the topic 'Sun elevation'

Author: Grafiati

Published: 28 June 2021

Last updated: 25 July 2025

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

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Sun elevation.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

WEYRAUCH, KARL F., and PATRICIA E. BOIKO. "Solar Intensity and Sun Protection." Pediatrics 85, no. 4 (1990): 626–27. http://dx.doi.org/10.1542/peds.85.4.626b.

Full text

Abstract:

To the Editor.— Weinstock et al1 observed "a significant association of melanoma with latitude of residence during the teenage years," thereby implying a direct relationship between solar radiation intensity and increasing tropical latitude. However, for specific locations, this relationship may not be true. For example, average daily solar radiation in Spokane, WA (latitude 47 degrees, 40 minutes, elevation 2400 feet), was 1314 BTU during July, compared to 862 BTU in Charleston, SC (latitude 32 degrees, 53 minutes, elevation sea level).2

APA, Harvard, Vancouver, ISO, and other styles

2

Bidschadler, R. A., and P. L. Vornberger. "Detailed elevation map of Ice Stream C, Antarctica, using satellite imagery and airborne radar." Annals of Glaciology 20 (1994): 327–35. http://dx.doi.org/10.3189/1994aog20-1-327-335.

Full text

Abstract:

Surface elevations collected by airborne radar arc interpolated between flight lines using Landsat I'M image data to produce a detailed digital elevation model of a part of Ice Stream C, West Antarctica. The photodinometric method developed is general and allows the derivation of surface elevation along any line parallel to the solar illumination from a single known elevation on that line. Accuracies of the derived elevations are improved with additional elevation control that permits an empirical determination of parameters in the photoclinometric equation accounting for albedo and atmospheri

APA, Harvard, Vancouver, ISO, and other styles

3

Bidschadler, R. A., and P. L. Vornberger. "Detailed elevation map of Ice Stream C, Antarctica, using satellite imagery and airborne radar." Annals of Glaciology 20 (1994): 327–35. http://dx.doi.org/10.1017/s0260305500016645.

Full text

Abstract:

Surface elevations collected by airborne radar arc interpolated between flight lines using Landsat I'M image data to produce a detailed digital elevation model of a part of Ice Stream C, West Antarctica. The photodinometric method developed is general and allows the derivation of surface elevation along any line parallel to the solar illumination from a single known elevation on that line. Accuracies of the derived elevations are improved with additional elevation control that permits an empirical determination of parameters in the photoclinometric equation accounting for albedo and atmospheri

APA, Harvard, Vancouver, ISO, and other styles

4

Chen, Y. T., B. H. Lim, and C. S. Lim. "General Sun Tracking Formula for Heliostats With Arbitrarily Oriented Axes." Journal of Solar Energy Engineering 128, no. 2 (2005): 245–50. http://dx.doi.org/10.1115/1.2189868.

Full text

Abstract:

The most general form of solar tracking formulae of an arbitrarily oriented heliostat toward an arbitrarily located target on the Earth is presented. With this complete solution, the used azimuth-elevation, spinning-elevation tracking formula, etc., are the special cases of it. Therefore, more application may be sought out for many individual cases in solar engineering. The new form of tracking solution could bring changes in the geometry and structure of the design of heliostat to meet various requirements.

APA, Harvard, Vancouver, ISO, and other styles

5

Chong, K. K., and M. H. Tan. "Comparison Study of Two Different Sun-Tracking Methods in Optical Efficiency of Heliostat Field." International Journal of Photoenergy 2012 (2012): 1–10. http://dx.doi.org/10.1155/2012/908364.

Full text

Abstract:

There are two sun-tracking methods widely used for the heliostat, which are conventional Azimuth-Elevation and revolutionary Spinning-Elevation methods. Following the previous study to compare the range of motion, a comparison study in optical efficiency of heliostat field for the two methods is further explored in this paper. A special algorithm using ray-tracing technique has also been developed to simulate the optical efficiency of heliostat field for both sun-tracking methods in different latitudes. With the new algorithm, comprehensive analysis to compare the optical efficiency of individ

APA, Harvard, Vancouver, ISO, and other styles

6

Reimann, Jens, and Martin Hagen. "Antenna Pattern Measurements of Weather Radars Using the Sun and a Point Source." Journal of Atmospheric and Oceanic Technology 33, no. 5 (2016): 891–98. http://dx.doi.org/10.1175/jtech-d-15-0185.1.

Full text

Abstract:

AbstractThe sun is known to be a good target for weather radar calibration. In this paper high-resolution raster scans of the sun at high elevations will be used to derive the antenna pattern of weather radar, without being affected by beam propagation effects and reflections close to the earth’s surface. It is shown that this pattern matches well to pattern measurements using a point source. Hence, a good estimation of the real antenna pattern can be derived using the sun.Furthermore, formulas to extract undistorted antenna patterns from the sun, even at high-elevation angles, are derived. Th

APA, Harvard, Vancouver, ISO, and other styles

7

Amiri, Mandana, Kevin Bandura, Anja Boskovic, et al. "Using the Sun to Measure the Primary Beam Response of the Canadian Hydrogen Intensity Mapping Experiment." Astrophysical Journal 932, no. 2 (2022): 100. http://dx.doi.org/10.3847/1538-4357/ac6b9f.

Full text

Abstract:

Abstract We present a beam pattern measurement of the Canadian Hydrogen Intensity Mapping Experiment (CHIME) made using the Sun as a calibration source. As CHIME is a pure drift-scan instrument, we rely on the seasonal north–south motion of the Sun to probe the beam at different elevations. This semiannual range in elevation, combined with the radio brightness of the Sun, enables a beam measurement that spans ∼7200 square degrees on the sky without the need to move the telescope. We take advantage of observations made near solar minimum to minimize the impact of solar variability, which is obs

APA, Harvard, Vancouver, ISO, and other styles

8

González-Camarillo, Héctor, Carlos A. Pérez-Rábago, Ramiro Calleja-Valdez, et al. "Closed-Loop Solar Tracking Control Strategy to Correct Drift in a CPV System Using Image Processing." Processes 13, no. 4 (2025): 944. https://doi.org/10.3390/pr13040944.

Full text

Abstract:

Tracking the apparent movement of the sun with high precision is crucial in dual-axis tracking systems for solar concentration applications. It is important to develop control strategies to reduce losses by solar radiation displacement (drift) on the receiver and improve the solar concentration system. In concentrated photovoltaics, a high-precision tracking control is required to keep the concentration point. This paper compares open-loop and closed-loop solar tracking control strategies to solve drift problems and correct azimuth and elevation angles in a non-image reflective FRESNEL solar c

APA, Harvard, Vancouver, ISO, and other styles

9

Liu, Chao, and Jing Hui. "Research on Physical MPPT of Photovoltaic Array System Based on Image Processing." Applied Mechanics and Materials 321-324 (June 2013): 1138–44. http://dx.doi.org/10.4028/www.scientific.net/amm.321-324.1138.

Full text

Abstract:

Based on analyzing the development and the performance feature of existing solar tracker, we propose a solar Maximum Power Point Tracking (MPPT) strategy which combines photoelectric sensor and image processing. Firstly, photoelectric tracking mode positions the sun in the field of view of the image sensor. Then, the position of the sun image is captured by the image sensor. After that, we can find the coordinates of the sun spot in the field of view through image binarization processing. According to the number of steps of stepper motor rotation which is calculated by the deviation of coordin

APA, Harvard, Vancouver, ISO, and other styles

10

Huuskonen, Asko, and Iwan Holleman. "Determining Weather Radar Antenna Pointing Using Signals Detected from the Sun at Low Antenna Elevations." Journal of Atmospheric and Oceanic Technology 24, no. 3 (2007): 476–83. http://dx.doi.org/10.1175/jtech1978.1.

Full text

Abstract:

Abstract A method to determine the elevation and azimuth biases of the radar antenna using solar signals observed by a scanning radar is presented. Data recorded at low elevation angles where the atmospheric refraction has a significant effect on the propagation of the radio wave are used, and a method to take the effect of the refraction into account in the analysis is presented. A set of equations is given by which the refraction of the radio waves as a function of the relative humidity can easily be calculated. Also, a simplified model for the calculation of the atmospheric attenuation is p

APA, Harvard, Vancouver, ISO, and other styles

11

Peart, David R., Matthew B. Jones, and Peter A. Palmiotto. "Winter injury to red spruce at Mount Moosilauke, New Hampshire." Canadian Journal of Forest Research 21, no. 9 (1991): 1380–89. http://dx.doi.org/10.1139/x91-195.

Full text

Abstract:

We report the severity and detailed spatial patterns of winter injury to red spruce (Picearubens Sarg.) in the winter of 1988–1989 and assess support for the desiccation and freezing hypotheses. Foliar injury was quantified at three elevations (840, 990, and 1140 m) and on east- and west-facing slopes in the spruce-fir zone at Mount Moosilauke, New Hampshire. Overall, 29% of current-year foliage on red spruce trees was killed by winter injury. Injury increased with elevation. There was a weak tendency for winter injury to be higher on the sun-exposed south sides of crowns, but substantial inju

APA, Harvard, Vancouver, ISO, and other styles

12

Abdel-Hadi, Yasser Abdel-Fattah, and Amir Hussein Hassan. "The Effect of Sun Elevation on the Twilight Stages in Malaysia." International Journal of Astronomy and Astrophysics 12, no. 01 (2022): 7–29. http://dx.doi.org/10.4236/ijaa.2022.121002.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Száz, Dénes, Alexandra Farkas, András Barta, Balázs Kretzer, Ádám Egri, and Gábor Horváth. "North error estimation based on solar elevation errors in the third step of sky-polarimetric Viking navigation." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 472, no. 2191 (2016): 20160171. http://dx.doi.org/10.1098/rspa.2016.0171.

Full text

Abstract:

The theory of sky-polarimetric Viking navigation has been widely accepted for decades without any information about the accuracy of this method. Previously, we have measured the accuracy of the first and second steps of this navigation method in psychophysical laboratory and planetarium experiments. Now, we have tested the accuracy of the third step in a planetarium experiment, assuming that the first and second steps are errorless. Using the fists of their outstretched arms, 10 test persons had to estimate the elevation angles (measured in numbers of fists and fingers) of black dots (represen

APA, Harvard, Vancouver, ISO, and other styles

14

Salim, Daniel Henrique Carneiro, Gabriela Rabelo Andrade, Alexandre Flávio Assunção, Pedro Henrique de Menezes Cosme, Gabriel Pereira, and Camila C. Amorim. "Assessing the Impact of Environmental Conditions on Reflectance Values in Inland Waters Using Multispectral UAS Imagery." Limnological Review 24, no. 4 (2024): 466–90. http://dx.doi.org/10.3390/limnolrev24040027.

Full text

Abstract:

This study investigates the impact of environmental conditions on reflectance values obtained from multispectral Unmanned Aerial System (UAS) imagery in inland waters, focusing on sun glint, cloud glint, wind-generated waves, and cloud shading projections. Conducted in two reservoirs with differing water qualities, UAS platforms equipped with MicaSense Altum and DJI Phantom 4 Multispectral sensors were used to collect multispectral images. The results show that sun glint significantly increases reflectance variability as solar elevation rises, particularly beyond 54°, compromising data quality

APA, Harvard, Vancouver, ISO, and other styles

15

Damanhuri, Adi, Maskufa, and Chairul Hadi. "Determining Subuh Prayer Time Using GNU Octave To Find Polynomial Roots." Azimuth: Journal of Islamic Astronomy 3, no. 1 (2022): 16–26. https://doi.org/10.15642/azimuth.v3i1.1055.

Full text

Abstract:

The standard used for the dawn prayer time schedule by the Indonesian government is the sun elevation angle 20°. That standard has been corrected a lot because it has not been assumed too late. Early research at dawn is mostly done using simple photometry tools, namely SQM, the processing of SQM output data varies, one of which is by polynomials, by reducing its function to the second derivative, and the first derivative root is substituted into the second derivative, so the turning point solution is represented by ?2y/?2t <0. The GNU Octave application helps to find the root of the first d

APA, Harvard, Vancouver, ISO, and other styles

16

Wang, Jiang, Yongchao Zhang, Yin Zhang, Yulin Huang, Jianyu Yang, and Yuming Du. "Performance in Solar Orientation Determination for Regular Pyramid Sun Sensors." Sensors 19, no. 6 (2019): 1424. http://dx.doi.org/10.3390/s19061424.

Full text

Abstract:

Non-planar sun sensors can determine solar orientation by existing photodiodes or by reusing solar panels, without increasing the size and mass of spacecraft. However, a limiting factor for the improvement of the accuracy of orientation lies in the lack of a detailed performance assessment on interference suppression. In this paper, a new method that determines solar orientation in the frequency domain is developed for regular pyramid sun sensors, which are formed by regular pyramid arrays. Furthermore, two formulations are established to evaluate the errors of the solar azimuth and elevation

APA, Harvard, Vancouver, ISO, and other styles

17

Lazarus, Brynne E., Paul G. Schaberg, Gary J. Hawley, and Donald H. DeHayes. "Landscape-scale spatial patterns of winter injury to red spruce foliage in a year of heavy region-wide injury." Canadian Journal of Forest Research 36, no. 1 (2006): 142–52. http://dx.doi.org/10.1139/x05-236.

Full text

Abstract:

Red spruce (Picea rubens Sarg.) winter injury is caused by freezing damage that results in the abscission of the most recent foliar age-class. Injury was widespread and severe in the northeastern United States in 2003 and was assessed at multiple elevations at 23 sites in Vermont and adjacent states. This paper presents a spatial analysis of these injury assessments. Relationships between winter injury on dominant and codominant spruce trees and elevation, latitude, longitude, slope, and aspect were investigated with least squares regression and geographically weighted regression. Results of t

APA, Harvard, Vancouver, ISO, and other styles

18

Száz, Dénes, Alexandra Farkas, András Barta, et al. "Accuracy of the hypothetical sky-polarimetric Viking navigation versus sky conditions: revealing solar elevations and cloudinesses favourable for this navigation method." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 473, no. 2205 (2017): 20170358. http://dx.doi.org/10.1098/rspa.2017.0358.

Full text

Abstract:

According to Thorkild Ramskou's theory proposed in 1967, under overcast and foggy skies, Viking seafarers might have used skylight polarization analysed with special crystals called sunstones to determine the position of the invisible Sun. After finding the occluded Sun with sunstones, its elevation angle had to be measured and its shadow had to be projected onto the horizontal surface of a sun compass. According to Ramskou's theory, these sunstones might have been birefringent calcite or dichroic cordierite or tourmaline crystals working as polarizers. It has frequently been claimed that this

APA, Harvard, Vancouver, ISO, and other styles

19

Martha, Tapas R., Norman Kerle, Cees J. van Westen, Victor Jetten, and K. Vinod Kumar. "Effect of Sun Elevation Angle on DSMs Derived from Cartosat-1 Data." Photogrammetric Engineering & Remote Sensing 76, no. 4 (2010): 429–38. http://dx.doi.org/10.14358/pers.76.4.429.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Igoe, D. P., and A. V. Parisi. "Solar current output as a function of sun elevation: students as toolmakers." Physics Education 50, no. 6 (2015): 657–61. http://dx.doi.org/10.1088/0031-9120/50/6/657.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Horton, S., M. Schirmer, and B. Jamieson. "Meteorological, elevation, and slope effects on surface hoar formation." Cryosphere Discussions 9, no. 2 (2015): 1857–85. http://dx.doi.org/10.5194/tcd-9-1857-2015.

Full text

Abstract:

Abstract. Failure in layers of buried surface hoar crystals (frost) can cause hazardous snow slab avalanches. Surface hoar crystals form on the snow surface and are sensitive to micro-meteorological conditions. In this study, the role of meteorological and terrain factors were investigated for three surface hoar layers in the Columbia Mountains of Canada. The distribution of crystals was observed over different elevations and aspects during 20 days of field observations. The same layers were modelled on a 2.5 km horizontal grid by forcing the snow cover model SNOWPACK with forecast weather dat

APA, Harvard, Vancouver, ISO, and other styles

22

KOROTKOV, A. L., M. P. ENGLISH, G. S. TUCKER, E. PASCALE, and N. GANDILO. "A PINHOLE SUN SENSOR FOR BALLOON-BORNE EXPERIMENT ATTITUDE DETERMINATION." Journal of Astronomical Instrumentation 02, no. 01 (2013): 1350005. http://dx.doi.org/10.1142/s2251171713500050.

Full text

Abstract:

We report on the design, calibration and in-flight performance of a sun sensor, which is used to determine the attitude of a balloon-borne telescope. The device uses a position-sensitive detector (PSD) in a pinhole camera. By determining the position of the image of the Sun on the PSD, the orientation of the sun sensor and the boresight of the telescope relative to the Sun can be determined. The pinhole sun sensor (PSS) was first flown in the December 2010 flight of the Balloon-borne Large Aperture Submillimeter Telescope with Polarization (BLAST-Pol). In flight the PSS achieved an accuracy (c

APA, Harvard, Vancouver, ISO, and other styles

23

Zhen, Cheng Gang, and Guo Jie Lu. "Research on Embedded Sun-Tracking Control System Based on GPS." Advanced Materials Research 512-515 (May 2012): 267–70. http://dx.doi.org/10.4028/www.scientific.net/amr.512-515.267.

Full text

Abstract:

To improve the efficiency of the power generation，the scheme of the solar tracking system is designed by analyzing the technical characteristics of the GPS positioning system. The microcontroller is chosen as the core which has realized the initiative sun-tracking to improve the efficiency of the power generation. The solar elevation angle and azimuth are calculated by extracting the GPS real-time datas. The position of the solar panels can be obtained through the angle sensor. Finally, adjust the orientation of the panels by the driving stepping motor to track the sun.

APA, Harvard, Vancouver, ISO, and other styles

24

Alexandru, C. "Modelling and simulation of a single-motor bi-axial sun tracking mechanism." IOP Conference Series: Materials Science and Engineering 1256, no. 1 (2022): 012021. http://dx.doi.org/10.1088/1757-899x/1256/1/012021.

Full text

Abstract:

Abstract This work deals with the modelling and simulation in a virtual environment of an innovative bi-axial solar tracker, with two degrees of freedom (DOF), at which the both movements (diurnal and elevation/altitudinal) are driven by a single motor (which is a linear actuator). The tracking mechanism is used for increasing the energetic efficiency of a photovoltaic (PV) platform. The proposed solution allows to reduce the cost of the PV system by minimizing the number of motors, but still preserving the tracking accuracy of the platform. The tracking system in study is one of azimuthal typ

APA, Harvard, Vancouver, ISO, and other styles

25

Li, Hong Yan, and Zhe Liu. "Design of a New GPS-Based Automatic Sun Tracking Control System." Advanced Materials Research 546-547 (July 2012): 987–91. http://dx.doi.org/10.4028/www.scientific.net/amr.546-547.987.

Full text

Abstract:

A key issue of the solar system is how to determine real-time position of the sun. This paper describes a new solar lighting system. The system uses a new GPS-based solar tracking control module. A Global Positioning System (GPS) is used to acquire latitude, longitude and the current time of the observation point. Single Chip Microcomputer Atmega168 is used to calculate the elevation angle and azimuth of the sun at this time, and to control the stepper motor rotating pan-tilt.. Using the angular position detector as a calibration device, the control system achieves accurate tracking of the sun

APA, Harvard, Vancouver, ISO, and other styles

26

Alwan, Ahmed, Ahmed Hameed, and Nuha Hamad. "Analyzing of UV Index with the Time Variation for Baghdad." Iraqi Journal of Industrial Research 8, no. 1 (2021): 50–54. http://dx.doi.org/10.53523/ijoirvol8i1id32.

Full text

Abstract:

In order to better realize the effects of UV index (UVI) reaching the earth surface, measurements of effective UVI were carried out during the period of one year over Baghdad; (Lat.33.32- Long.44.45), which receives highly amounts of annual solar radiation. A daily data analysis of UVI is found to reach the highest value during summer reaching the value of 11, and a minimum in winter with the value of 1. A relation between UV index and the solar zenith angle was also, it is found that the UVI is highly dependent on the sun elevation where the atmospheric optical path becomes shorter as sun ele

APA, Harvard, Vancouver, ISO, and other styles

27

Ionov, Pavel I., and Andrew K. Mollner. "Aerosol Optical Thickness Measurement with Elevation-Scanning Lidar." Journal of Atmospheric and Oceanic Technology 32, no. 7 (2015): 1364–71. http://dx.doi.org/10.1175/jtech-d-14-00183.1.

Full text

Abstract:

AbstractHigh-accuracy measurement of aerosol optical thickness (AOT) τa with an elevation-scanning lidar is demonstrated and the results are compared with a collocated Cimel 318 sun photometer. Linear regression of the time-coincident data from a 2-week measurement campaign with the two instruments is found to be τalidar = (1.00 ± 0.17)τaphot + (0.025 ± 0.019) (1σ). The method proved to have sufficient accuracy to measure AOTs of 0.1–0.2 commonly seen in relatively clear atmosphere. The measurement is absolute and thus does not depend on any external calibration standards.

APA, Harvard, Vancouver, ISO, and other styles

28

Weihs, Philipp, Sarah Helletzgruber, Sofie Kranewitter, et al. "UV Exposure during Cycling as a Function of Solar Elevation and Orientation." Atmosphere 15, no. 2 (2024): 215. http://dx.doi.org/10.3390/atmos15020215.

Full text

Abstract:

Although cycling is the most prevalent means of locomotion in the world, little research has been done in evaluating the ultraviolet (UV) radiation exposure of cyclists. In this study, a volunteer using a men’s bike was equipped with 10 miniature UV-meters at different body sites. Besides erythemally effective irradiance, the ratio of personal UV exposure to ambient UV radiation was determined for solar elevations up to 65°, taking into account different orientations with respect to the sun. This method provides a universal model that allows for the calculation of UV exposure whenever ambient

APA, Harvard, Vancouver, ISO, and other styles

29

Horton, S., M. Schirmer, and B. Jamieson. "Meteorological, elevation, and slope effects on surface hoar formation." Cryosphere 9, no. 4 (2015): 1523–33. http://dx.doi.org/10.5194/tc-9-1523-2015.

Full text

Abstract:

Abstract. Failure in layers of buried surface hoar crystals (frost) can cause hazardous snow slab avalanches. Surface hoar crystals form on the snow surface and are sensitive to micro-meteorological conditions. In this study, the role of meteorological and terrain factors was investigated for three layers of surface hoar in the Columbia Mountains of Canada. The distribution of crystals over different elevations and aspects was observed on 20 days of field observations during a period of high pressure. The same layers were modelled over simplified terrain on a 2.5 km horizontal grid by forcing

APA, Harvard, Vancouver, ISO, and other styles

30

Howard, Rosie, and Roland Stull. "Forecasting Sun versus Shade in Complex Terrain for the 2010 Winter Olympic and Paralympic Games." Bulletin of the American Meteorological Society 92, no. 10 (2011): 1303–9. http://dx.doi.org/10.1175/2011bams-d-11-00017.1.

Full text

Abstract:

During the 2010 Vancouver Winter Olympic and Paralympic Games in Canada, there were 10 mostly sunny days at the outdoor Olympic venues. The warmth and sunshine, possibly a result of El Niño conditions at the time, significantly reduced snow cover at one venue and weakened the snowpack at the other two venues, much to the chagrin of the event organizers. Solar radiation affects ski racing via its effect on snow-surface friction, abrasion, and mechanical strength. Ski technicians and athletes compensate via the choice of ski and wax. For these reasons, sun-versus-shade forecasts were produced fo

APA, Harvard, Vancouver, ISO, and other styles

31

Porter, John N., Antony Clarke, Jeffrey S. Reid, et al. "Handheld Sun Photometer Measurements from Light Aircraft*." Journal of Atmospheric and Oceanic Technology 24, no. 9 (2007): 1588–97. http://dx.doi.org/10.1175/jtech2087.1.

Full text

Abstract:

Abstract Handheld sun photometers are typically used to make aerosol optical depth measurements while on the ground. Various investigators, in unrelated efforts, have used handheld sun photometers to make aerosol optical depth measurements from light aircraft, but the strengths and weakness of this approach have not been characterized until now. While the ease and relatively low cost of an aircraft manual sun photometer are attractive, determining if the sun photometer was correctly pointed at the sun for each measurement is the biggest challenge. This problem can be partially addressed by col

APA, Harvard, Vancouver, ISO, and other styles

32

Tomanová, Helena, and Lucie Pokorná. "The effect of sun elevation, cloudiness, and altitude on the ultraviolet index in Czechia." Geografie 126, no. 2 (2021): 221–42. http://dx.doi.org/10.37040/geografie.2021.001.

Full text

Abstract:

Ultraviolet (UV) radiation has recently become an important topic in relation to the loss of stratospheric ozone. High doses of UV radiation have a negative effect on many organisms. This paper focuses on the UV index (UVI), which expresses the risk of UV radiation on human health. The aim of the paper is to describe the definition of UVI, and its measurement, and to summarize geographical parameters and meteorological conditions affecting the values of UVI. The effect of sun elevation, cloudiness, and altitude is demonstrated using observed data from the Hradec Králové, Košetice and Labská bo

APA, Harvard, Vancouver, ISO, and other styles

33

Brabec, Marek, Alexandru Dumitrescu, Marius Paulescu, and Viorel Badescu. "A new perspective on the sunshine duration variability." Theoretical and Applied Climatology 139, no. 3-4 (2019): 1219–30. https://doi.org/10.5281/zenodo.13365615.

Full text

Abstract:

The sunshine duration data is analysed here from a new perspective, different from the traditional ones. The study is focused on pairs of periods of shining sun (called clear periods) followed by periods with the sun covered by clouds (called dark periods). Their statistical and sequential properties are illustrated by using results obtained from satellite observations and ground measurements at Timisoara (Romania). Solar irradiance time series measured at ground are converted into a database consisting of pairs of clear/dark periods. These pairs are associated with three cloud classes derived

APA, Harvard, Vancouver, ISO, and other styles

34

Aoyama, Hiroyuki, and Yuichi Nakajo. "D114 A Panel Type Solar Cooker for the Areas with Low Sun Elevation." Proceedings of the National Symposium on Power and Energy Systems 2008.13 (2008): 175–78. http://dx.doi.org/10.1299/jsmepes.2008.13.175.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Chen, Y. T., A. Kribus, B. H. Lim, et al. "Comparison of Two Sun Tracking Methods in the Application of a Heliostat Field." Journal of Solar Energy Engineering 126, no. 1 (2004): 638–44. http://dx.doi.org/10.1115/1.1634583.

Full text

Abstract:

The basic mathematics and structure of heliostat have remained unchanged for many decades. Following the challenge first made by Ries et al., the non-imaging focusing heliostat recently proposed by Chen et al. provides an alternative in the field of concentrated solar energy. This paper investigates the performance of a heliostat field composed of the newly proposed heliostats. In contrast to the dynamic curvature adjustment proposed in our previous work for a solar furnace, a fixed asymmetric curvature is used here with the spinning-elevation tracking method. This restriction is intended to e

APA, Harvard, Vancouver, ISO, and other styles

36

Gui, Mingzhen, Hua Yang, Dangjun Zhao, Mingzhe Dai, and Chengxi Zhang. "Analysis and Compensation of Sun Direction Error on Solar Disk Velocity Difference." Mathematics 11, no. 17 (2023): 3716. http://dx.doi.org/10.3390/math11173716.

Full text

Abstract:

Solar disk velocity difference is an emerging celestial navigation measurement acquired through four spectrometers positioned on the four corners of the quadrangular pyramid. The alignment of the pyramid’s axis with the direction from the sun to the spacecraft is crucial. However, the sun sensor measurement error inevitably leads to the sun direction error, which both significantly affect navigation accuracy. To address this issue, this article proposes an augmented state sun direction/solar disk velocity difference integrated navigation method. By analyzing the impact of the sun direction err

APA, Harvard, Vancouver, ISO, and other styles

37

Horváth, Gábor, Péter Takács, Balázs Kretzer, et al. "Celestial polarization patterns sufficient for Viking navigation with the naked eye: detectability of Haidinger's brushes on the sky versus meteorological conditions." Royal Society Open Science 4, no. 2 (2017): 160688. http://dx.doi.org/10.1098/rsos.160688.

Full text

Abstract:

If a human looks at the clear blue sky from which light with high enough degree of polarization d originates, an 8-shaped bowtie-like figure, the yellow Haidinger's brush can be perceived, the long axis of which points towards the sun. A band of high d arcs across the sky at 90° from the sun. A person can pick two points on that band, observe the yellow brushes and triangulate the position of the sun based on the orientation of the two observed brushes. This method has been suggested to have been used on the open sea by Viking navigators to determine the position of the invisible sun occluded

APA, Harvard, Vancouver, ISO, and other styles

38

CÉSPEDES, LAURA N., and NICHOLAS J. BAYLY. "Over-winter ecology and relative density of Canada Warbler Cardellina canadensis in Colombia: the basis for defining conservation priorities for a sharply declining long-distance migrant." Bird Conservation International 29, no. 2 (2018): 232–48. http://dx.doi.org/10.1017/s0959270918000229.

Full text

Abstract:

SummaryThe Canada Warbler Cardellina canadensis is a steeply declining Neotropical migratory bird and > 50% of its non-breeding range is within the Colombian Andes. Despite being an abundant migrant in Andean forests, the species’ elevational distribution and non-breeding ecology have yet to be studied, thereby precluding the design of effective conservation actions. During four non-breeding periods (2012–2016), we surveyed Colombia’s three Andean ranges, carrying out passive 5-minute point counts between 700 and 3,150 m asl in five habitats (mature forest, secondary growth, forest edges/ri

APA, Harvard, Vancouver, ISO, and other styles

39

Altube, Patricia, Joan Bech, Oriol Argemí, Tomeu Rigo, and Nicolau Pineda. "Intercomparison and Potential Synergies of Three Methods for Weather Radar Antenna Pointing Assessment." Journal of Atmospheric and Oceanic Technology 33, no. 2 (2016): 331–43. http://dx.doi.org/10.1175/jtech-d-15-0075.1.

Full text

Abstract:

AbstractThree methods for estimation of the weather radar antenna azimuth and elevation pointing offsets are compared. Two of the methods reviewed use the known location of the sun as a reference. The first of these methods is based on an offline scan of the sun disk. The second method detects and characterizes solar interferences in operative scans. The third method consists of correlating measured ground clutter echoes with echoes simulated using a high-resolution digital elevation model. The main objectives are to review the characteristics in each case, studying their performance in actual

APA, Harvard, Vancouver, ISO, and other styles

40

Lu, Qi Rong, Lei Wang, Qi Lin Tang, and Yu Jian Yang. "The New Method of Solar Power Generation Using Spin Angle and Elevation Angle Program Control with LabVIEW." Advanced Materials Research 756-759 (September 2013): 650–54. http://dx.doi.org/10.4028/www.scientific.net/amr.756-759.650.

Full text

Abstract:

In order to reduce the power consumption of traditional tracking control, this article according to the tracking theory of spin new angle of elevation design of high precision two-axis solar tracking controller based on LabVIEW programming. The main method of control mode to calculate the position of the sun, using the S1337-1010BQ sensor to track the sun angle deviation automatic proofreading. According to the light intensity automatically adjust the reset program, can maximize the more light. After the test, a new tracking method tracking error is reduced, the photovoltaic efficiency is furt

APA, Harvard, Vancouver, ISO, and other styles

41

Bramstedt, K., S. Noël, H. Bovensmann, M. Gottwald, and J. P. Burrows. "Precise pointing knowledge for SCIAMACHY solar occultation measurements." Atmospheric Measurement Techniques 5, no. 11 (2012): 2867–80. http://dx.doi.org/10.5194/amt-5-2867-2012.

Full text

Abstract:

Abstract. We present a method to precisely determine the viewing direction for solar occultation instruments from scans over the solar disk. Basic idea is the fit of the maximum intensity during the scan, which corresponds to the center of the solar disk in the scanning direction. We apply this method to the solar occultation measurements of the satellite instrument SCIAMACHY, which scans the Sun in elevation direction. The achieved mean precision is 0.46 mdeg, which corresponds to an tangent height error of about 26 m for individual occultation sequences. The deviation of the derived elevatio

APA, Harvard, Vancouver, ISO, and other styles

42

Chiang, Camilo, Jorunn E. Olsen, David Basler, Daniel Bånkestad, and Günter Hoch. "Latitude and Weather Influences on Sun Light Quality and the Relationship to Tree Growth." Forests 10, no. 8 (2019): 610. http://dx.doi.org/10.3390/f10080610.

Full text

Abstract:

Natural changes in photoperiod, light quantity, and quality play a key role in plant signaling, enabling daily and seasonal adjustment of growth and development. Growing concern about the global climate crisis together with scattered reports about the interactive effects of temperature and light parameters on plants necessitates more detailed information about these effects. Furthermore, the actual light emitting diode (LED) lighting technology allows mimicking of light climate scenarios more similar to natural conditions, but to fully exploit this in plant cultivation, easy-to-apply knowledge

APA, Harvard, Vancouver, ISO, and other styles

43

Song, Guoyang, Defa Han, Yingge Li, Zhaoming He, and Dongxing Du. "Enhancement of solar panel power generation performance with a passive sun tracking system." Thermal Science and Engineering 7, no. 1 (2024): 7906. http://dx.doi.org/10.24294/tse.v7i1.7906.

Full text

Abstract:

In this paper, a solar tracking device that can continuously track the sun by adjusting the direction and angle of the solar panel in real time is designed and fabricated to improve the power generation efficiency of the solar cell panel. The mechanical parts as well as the automatic control part of the passive sun-tracking system are described, and the efficiency enhancement with the sun-tracking solar panel is characterized in comparison with the fixed panel system. The test results show that in the spring season in Qingdao city of eastern China, the sun-tracking system can improve the solar

APA, Harvard, Vancouver, ISO, and other styles

44

Toledano, Carlos, Ramiro González, David Fuertes, et al. "Assessment of Sun photometer Langley calibration at the high-elevation sites Mauna Loa and Izaña." Atmospheric Chemistry and Physics 18, no. 19 (2018): 14555–67. http://dx.doi.org/10.5194/acp-18-14555-2018.

Full text

Abstract:

Abstract. The aim of this paper is to analyze the suitability of the high-mountain stations Mauna Loa and Izaña for Langley plot calibration of Sun photometers. Thus the aerosol optical depth (AOD) characteristics and seasonality, as well as the cloudiness, have been investigated in order to provide a robust estimation of the calibration uncertainty as well as the number of days that are suitable for Langley calibrations. The data used for the investigations belong to the AERONET and GAW-PFR networks, which maintain reference Sun photometers at these stations with long measurement records: 22

APA, Harvard, Vancouver, ISO, and other styles

45

Tognon, G., S. Ferrari, L. Penasa, et al. "Spectrophotometric variegation of the layering in comet 67P/Churyumov-Gerasimenko as seen by OSIRIS." Astronomy & Astrophysics 630 (September 20, 2019): A16. http://dx.doi.org/10.1051/0004-6361/201834884.

Full text

Abstract:

Context. Between August 2014 and September 2016, the ESA space mission Rosetta escorted comet 67P/Churyumov-Gerasimenko (67P) during its perihelion passage. The onboard OSIRIS Narrow Angle Camera (NAC) acquired high-resolution multispectral images of the cometary surface. These datasets allowed a characterization of the spectrophotometric variegation of the layering of the large lobe, correlated with the layer structural elevation. Aims. We perform a spectrophotometric characterization of the outcropping stratification of the small lobe of 67P as a function of its structural elevation, and con

APA, Harvard, Vancouver, ISO, and other styles

46

Apaolaza-Pagoaga, Xabier, Atul A. Sagade, Celestino Rodrigues Ruivo, and Antonio Carrillo-Andrés. "Performance of solar funnel cookers using intermediate temperature test load under low sun elevation." Solar Energy 225 (September 2021): 978–1000. http://dx.doi.org/10.1016/j.solener.2021.08.006.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Montesano, Paul M., Christopher Neigh, Guoqing Sun, Laura Duncanson, Jamon Van Den Hoek, and K. Jon Ranson. "The use of sun elevation angle for stereogrammetric boreal forest height in open canopies." Remote Sensing of Environment 196 (July 2017): 76–88. http://dx.doi.org/10.1016/j.rse.2017.04.024.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Zhan, Yinhu, Shaojie Chen, and Donghan He. "High-Precision Heading Determination Based on the Sun for Mars Rover." Advances in Astronomy 2018 (August 1, 2018): 1–14. http://dx.doi.org/10.1155/2018/1493954.

Full text

Abstract:

Since the American Mars Exploration Rover Opportunity landed on Mars in 2004, it has travelled more than 40 km, and heading-determination technology based on its sun sensor has played an important role in safe driving of the rover. A high-precision heading-determination method will always play a significant role in the rover’s autonomous navigation system, and the precision of the measured heading strongly affects the navigation results. In order to improve the heading precision to the 1-arcminute level, this paper puts forward a novel calibration algorithm for solving the comparable distortio

APA, Harvard, Vancouver, ISO, and other styles

49

Bramstedt, K., S. Noël, H. Bovensmann, M. Gottwald, and J. P. Burrows. "Precise pointing knowledge for SCIAMACHY solar occultation measurements." Atmospheric Measurement Techniques Discussions 5, no. 3 (2012): 3797–835. http://dx.doi.org/10.5194/amtd-5-3797-2012.

Full text

Abstract:

Abstract. We present a method to precisely determine the viewing direction for solar occultation instruments from scans over the solar disk . Basic idea is the fit of the maximum intensity during the scan, which corresponds to the center of the solar disk in the scanning direction. We apply this method to the solar occultation measurements of the satellite instrument SCIAMACHY, which scans the sun in elevation direction. The achieved precision is in most case below 0.6 mdeg, which corresponds to an tangent height error of about 34 m for individual occultation sequences. The deviation of the de

APA, Harvard, Vancouver, ISO, and other styles

50

Mamodiya, Udit, and Neeraj Tiwari. "Investigation for Performance Comparison of Solar Tracking System with Static Solar System." ECS Transactions 107, no. 1 (2022): 8551–59. http://dx.doi.org/10.1149/10701.8551ecst.

Full text

Abstract:

Around the world, sun oriented force has become the third greatest wellspring of vitality after hydro and twist, in this manner, grabbing a worldwide eye. This investigation draws a correlation between the presentation of Solar Tracker and Static Solar System or a nearby planetary group with fixed pivot to evaluate the sunlight based force. By utilizing different sun points, for example, peak, sunlight based elevation, and solar altitude, sun powered irradiance was determined during a day either shady or radiant, while the aggregate vitality created during the entire month was additionally est

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!