scholarly journals Phase-angle dependence of colour ratios and potential implications for lunar remote sensing

2020 ◽  
Vol 644 ◽  
pp. A30
Author(s):  
Yazhou Yang ◽  
Pei Ma ◽  
Le Qiao ◽  
Hao Zhang ◽  
Weidong Jin ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Particle Size ◽  
Phase Angle ◽  
Remote Sensing Data ◽  
Target Surface ◽  
Phase Dependence ◽  
Imaging Device ◽  
Angle Dependence ◽  
Solar Phase ◽  
Phase Angles

Context. The colour-ratio technique has been widely used in mapping planetary surfaces, but its solar phase-angle dependence is not well understood. Understanding the phase-angle dependence of the colour ratio would enhance our abilities in interpreting planetary remote sensing data. Aims. We aim to investigate the dependence of the colour ratio indices on mineralogy, phase angle, particle size, and the degree of simulated space weathering. Methods. We measured the multi-band (i.e. 458, 633, 750, and 905 nm) and multi-angle reflectance spectra of four typical lunar-type minerals with different particle sizes using a custom multi-angular imaging device. Results. The colour ratio does have a phase-angle dependence that is more sensitive to the mineralogy and wavelength and less sensitive to particle size distribution. Conclusions. The combined analysis of the colour ratio and its phase dependence can improve efficiency in mapping the lunar surface. With a prior knowledge of the phase behaviours of colour ratios of specific lunar-type minerals, an optimised colour ratio at certain phase angles can be found to efficiently distinguish the composition of a target surface.

scholarly journals Polarimetry of Saturnian satellite Enceladus

2015 ◽  
Vol 5 (1) ◽  
pp. 29-32 ◽  
Author(s):  
S. Zaitsev ◽  
N. Kiselev ◽  
V. Rosenbush ◽  
S. Kolesnikov ◽  
D. Shakhovskoy
Keyword(s):  
Light Scattering ◽  
Phase Angle ◽  
Linear Polarization ◽  
Spectral Band ◽  
Crimean Astrophysical Observatory ◽  
Angle Dependence ◽  
Phase Angles ◽  
Saturnian Satellite

We present results of polarimetric observations of Saturn's moon Enceladus carried out from April 14, 2010 to April 13, 2013 in WR spectral band (550-750 nm). We used 2.6-m telescope equipped with a one-channel photoelectric photometer-polarimeter (Crimean Astrophysical Observatory). The measurements were performed at phase angles ranging from 1.65° to 5.71°. The phase-angle dependence of linear polarization of Enceladus was obtained using the results of our observations. Results obtained are discussed in terms of existing models of light scattering by regolith surfaces.

scholarly journals In situ sampled snow particle sizes of the East Antarctic ice sheet and their relation to physical and remotely sensed snow surface parameters

2013 ◽  
Vol 54 (62) ◽  
pp. 166-174
Author(s):  
Susanne Ingvander ◽  
Helen E. Dahlke ◽  
Peter Jansson ◽  
Sylviane Surdyk
Keyword(s):  
Remote Sensing ◽  
Particle Size ◽  
Ice Sheet ◽  
Remote Sensing Data ◽  
Antarctic Ice Sheet ◽  
Sensing Data ◽  
Snow Particle ◽  
Particle Length ◽  
East Antarctic Ice Sheet

AbstractKnowledge of snow properties across Antarctica is important in estimating how climate could potentially influence the mass balance of the Antarctic ice sheet. However, measuring these variables has proven to be challenging because appropriate techniques have not yet been developed and extensive datasets of field estimates are lacking. The goal of this study was to estimate the relationship between field-observed snow particle-size parameters from across the East Antarctic ice sheet and a suite of spatial datasets (i.e. topography, remote-sensing data) using a principal component analysis (PCA). Five snow particle-size parameters were correlated to spatial datasets of the following five groups: (1) relief properties such as elevation and slope; (2) remote-sensing data from Moderate Resolution Imaging Spectroradiometer (MODIS) and synthetic aperture radar (SAR) sensors; (3) spatially interpolated data (i.e. 10 m maps of temperature and approximate snow accumulation in kgm−2 ä−1); (4) field-retrieved data on surface roughness; and (5) in situ elevation and distance from the coast. The results show that the relief parameter slope correlated best with the snow particle length and area (r=0.76, r=0.80). Further, the PCA indicated that the different remote-sensing parameters correlated differently with the size parameters and that the most common parameter in visual analysis, particle length (grain diameter), is not always the optimal parameter to characterize the snow particle size as, for example, area correlates better to slope and aspect than length.

Improved algorithm of aerosol particle size distribution based on remote sensing data

2019 ◽  
Vol 58 (29) ◽  
pp. 8075 ◽  
Author(s):  
Qing Yan ◽  
Huige Di ◽  
Jing Zhao ◽  
Xiaonan Wen ◽  
Yufeng Wang ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Aerosol Particle ◽  
Remote Sensing Data ◽  
Sensing Data ◽  
Aerosol Particle Size ◽  
Improved Algorithm

The Occurrence of Particle Size Distribution Bimodality in Midlatitude Cirrus as Inferred from Ground-Based Remote Sensing Data

2011 ◽  
Vol 68 (6) ◽  
pp. 1162-1177 ◽  
Author(s):  
Yang Zhao ◽  
Gerald G. Mace ◽  
Jennifer M. Comstock
Keyword(s):  
Remote Sensing ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Size Range ◽  
Remote Sensing Data ◽  
General Nature ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Sensing Data

Abstract Data collected in midlatitude cirrus clouds by instruments on jet aircraft typically show particle size distributions that have distinct distribution modes in both the 10–30-μm maximum dimension (D) size range and the 200–300-μm D size range or larger. A literal interpretation of the small D mode in these datasets suggests that total concentrations Nt in midlatitude cirrus are, on average, well in excess of 1 cm−3 whereas more conventional analyses of in situ data and cloud process model results suggest Nt values a factor of 10 less. Given this wide discrepancy, questions have been raised regarding the influence of data artifacts caused by the shattering of large crystals on aircraft and probe surfaces. This inconsistency and the general nature of the cirrus particle size distribution are examined using a ground-based remote sensing dataset. An algorithm using millimeter-wavelength radar Doppler moments and Raman lidar-derived extinction is developed to retrieve a bimodal particle size distribution and its uncertainty. This algorithm is applied to case studies as well as to 313 h of cirrus measurements collected at the Atmospheric Radiation Measurement site near Lamont, Oklahoma, in 2000. It is shown that particle size distributions in cirrus can often be described as bimodal, and that this bimodality is a function of temperature and location within cirrus layers. However, the existence of Nt > 1 cm−3 in cirrus is rare (<1% of the time) and the Nt implied by the remote sensing data tends to be on the order of 100 cm−3.

Monitoring land use change in the Lake Taupo catchment between 1975, 1990 and 2002 using satellite remote sensing data

2007 ◽  
pp. 17-22
Author(s):  
H. Lilienthal ◽  
A. Brauer ◽  
K. Betteridge ◽  
E. Schnug
Keyword(s):  
Remote Sensing ◽  
Water Quality ◽  
Land Use ◽  
Land Use Change ◽  
Satellite Remote Sensing ◽  
Remote Sensing Data ◽  
Native Vegetation ◽  
Lake Water Quality ◽  
Livestock Farming ◽  
Slow Decline

Conversion of native vegetation into farmed grassland in the Lake Taupo catchment commenced in the late 1950s. The lake's iconic value is being threatened by the slow decline in lake water quality that has become apparent since the 1970s. Keywords: satellite remote sensing, nitrate leaching, land use change, livestock farming, land management

Assessment of the national market demand for high-resolution remote sensing data

2002 ◽  
Vol 8 (1) ◽  
pp. 15-22
Author(s):  
V.N. Astapenko ◽  
◽  
Ye.I. Bushuev ◽  
V.P. Zubko ◽  
V.I. Ivanov ◽  
...  
Keyword(s):  
Remote Sensing ◽  
High Resolution ◽  
Remote Sensing Data ◽  
Market Demand ◽  
Sensing Data ◽  
National Market
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