Circular polarization ratio characteristics of impact craters from Mini-RF observations and implications for ice detection at the polar regions of the Moon
In an attempt to reduce the ambiguity on radar detection of water ice at the permanently shadowed regions near the lunar poles, radar echo strength and circular polarization ratio (CPR) of impact craters are analyzed using the Miniature Radio Frequency (Mini-RF) radar data from the Lunar Reconnaissa...
Published in: | Journal of Geophysical Research: Planets |
---|---|
Main Authors: | , |
Other Authors: | , , |
Format: | Journal/Newspaper |
Language: | English |
Published: |
journal of geophysical research planets
2013
|
Subjects: | |
Online Access: | https://hdl.handle.net/20.500.11897/155604 https://doi.org/10.1002/jgre.20110 |
id |
ftpekinguniv:oai:localhost:20.500.11897/155604 |
---|---|
record_format |
openpolar |
spelling |
ftpekinguniv:oai:localhost:20.500.11897/155604 2023-05-15T18:23:13+02:00 Circular polarization ratio characteristics of impact craters from Mini-RF observations and implications for ice detection at the polar regions of the Moon Fa, Wenzhe Cai, Yuzhen Fa, WZ (reprint author), Peking Univ, Inst Remote Sensing & Geog Informat Syst, 5 Yiheyuan Rd, Beijing 100871, Peoples R China. Peking Univ, Inst Remote Sensing & Geog Informat Syst, Beijing 100871, Peoples R China. Peking Univ, Inst Remote Sensing & Geog Informat Syst, 5 Yiheyuan Rd, Beijing 100871, Peoples R China. 2013 https://hdl.handle.net/20.500.11897/155604 https://doi.org/10.1002/jgre.20110 en eng journal of geophysical research planets JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS.2013,118,(8),1582-1608. 814857 2169-9097 http://hdl.handle.net/20.500.11897/155604 doi:10.1002/jgre.20110 WOS:000325007100002 SCI Moon ice deposits circular polarization ratio surface slope rocks craters LUNAR SOUTH-POLE COHERENT-BACKSCATTER 70-CM WAVELENGTH RADAR ECHOES DEPOSITS ARECIBO MERCURY SURFACE IMAGES WATER Journal 2013 ftpekinguniv https://doi.org/20.500.11897/155604 https://doi.org/10.1002/jgre.20110 2021-08-01T08:02:46Z In an attempt to reduce the ambiguity on radar detection of water ice at the permanently shadowed regions near the lunar poles, radar echo strength and circular polarization ratio (CPR) of impact craters are analyzed using the Miniature Radio Frequency (Mini-RF) radar data from the Lunar Reconnaissance Orbiter mission. Eight typical craters, among over 70 craters, are selected and classified into four categories based on their locations and CPR characteristics: polar anomalous, polar fresh, nonpolar anomalous, and nonpolar fresh. The influences on CPR caused by surface slope, rocks, and dielectric constant are analyzed quantitatively using high-resolution topography data and optical images. A two-component mixed model for CPR that consists of a normal surface and a rocky surface is developed to study the effect of rocks that are perched on lunar surface and buried in regolith. Our analyses show that inner wall of a typical bowl-shaped crater can give rise to a change of about 30 degrees in local incidence angle of radar wave, which can further result in a CPR difference of about 0.2. There is a strong correlation between Mini-RF CPR and rock abundance that is obtained from high-resolution optical images, and predictions from the two-component mixed model match well with the observed CPRs and the estimated rock abundances. Statistical results show that there is almost no apparent difference in CPR characteristics between the polar and nonpolar anomalous craters, or between the polar and nonpolar fresh craters. The enhanced CPR in the interior of anomalous craters is most probably caused by rocks that are perched on lunar surface or buried in regolith, instead of ice deposits as suggested in previous studies. Geochemistry & Geophysics SCI(E) 4 ARTICLE 8 1582-1608 118 Journal/Newspaper South pole Peking University Institutional Repository (PKU IR) South Pole Journal of Geophysical Research: Planets 118 8 1582 1608 |
institution |
Open Polar |
collection |
Peking University Institutional Repository (PKU IR) |
op_collection_id |
ftpekinguniv |
language |
English |
topic |
Moon ice deposits circular polarization ratio surface slope rocks craters LUNAR SOUTH-POLE COHERENT-BACKSCATTER 70-CM WAVELENGTH RADAR ECHOES DEPOSITS ARECIBO MERCURY SURFACE IMAGES WATER |
spellingShingle |
Moon ice deposits circular polarization ratio surface slope rocks craters LUNAR SOUTH-POLE COHERENT-BACKSCATTER 70-CM WAVELENGTH RADAR ECHOES DEPOSITS ARECIBO MERCURY SURFACE IMAGES WATER Fa, Wenzhe Cai, Yuzhen Circular polarization ratio characteristics of impact craters from Mini-RF observations and implications for ice detection at the polar regions of the Moon |
topic_facet |
Moon ice deposits circular polarization ratio surface slope rocks craters LUNAR SOUTH-POLE COHERENT-BACKSCATTER 70-CM WAVELENGTH RADAR ECHOES DEPOSITS ARECIBO MERCURY SURFACE IMAGES WATER |
description |
In an attempt to reduce the ambiguity on radar detection of water ice at the permanently shadowed regions near the lunar poles, radar echo strength and circular polarization ratio (CPR) of impact craters are analyzed using the Miniature Radio Frequency (Mini-RF) radar data from the Lunar Reconnaissance Orbiter mission. Eight typical craters, among over 70 craters, are selected and classified into four categories based on their locations and CPR characteristics: polar anomalous, polar fresh, nonpolar anomalous, and nonpolar fresh. The influences on CPR caused by surface slope, rocks, and dielectric constant are analyzed quantitatively using high-resolution topography data and optical images. A two-component mixed model for CPR that consists of a normal surface and a rocky surface is developed to study the effect of rocks that are perched on lunar surface and buried in regolith. Our analyses show that inner wall of a typical bowl-shaped crater can give rise to a change of about 30 degrees in local incidence angle of radar wave, which can further result in a CPR difference of about 0.2. There is a strong correlation between Mini-RF CPR and rock abundance that is obtained from high-resolution optical images, and predictions from the two-component mixed model match well with the observed CPRs and the estimated rock abundances. Statistical results show that there is almost no apparent difference in CPR characteristics between the polar and nonpolar anomalous craters, or between the polar and nonpolar fresh craters. The enhanced CPR in the interior of anomalous craters is most probably caused by rocks that are perched on lunar surface or buried in regolith, instead of ice deposits as suggested in previous studies. Geochemistry & Geophysics SCI(E) 4 ARTICLE 8 1582-1608 118 |
author2 |
Fa, WZ (reprint author), Peking Univ, Inst Remote Sensing & Geog Informat Syst, 5 Yiheyuan Rd, Beijing 100871, Peoples R China. Peking Univ, Inst Remote Sensing & Geog Informat Syst, Beijing 100871, Peoples R China. Peking Univ, Inst Remote Sensing & Geog Informat Syst, 5 Yiheyuan Rd, Beijing 100871, Peoples R China. |
format |
Journal/Newspaper |
author |
Fa, Wenzhe Cai, Yuzhen |
author_facet |
Fa, Wenzhe Cai, Yuzhen |
author_sort |
Fa, Wenzhe |
title |
Circular polarization ratio characteristics of impact craters from Mini-RF observations and implications for ice detection at the polar regions of the Moon |
title_short |
Circular polarization ratio characteristics of impact craters from Mini-RF observations and implications for ice detection at the polar regions of the Moon |
title_full |
Circular polarization ratio characteristics of impact craters from Mini-RF observations and implications for ice detection at the polar regions of the Moon |
title_fullStr |
Circular polarization ratio characteristics of impact craters from Mini-RF observations and implications for ice detection at the polar regions of the Moon |
title_full_unstemmed |
Circular polarization ratio characteristics of impact craters from Mini-RF observations and implications for ice detection at the polar regions of the Moon |
title_sort |
circular polarization ratio characteristics of impact craters from mini-rf observations and implications for ice detection at the polar regions of the moon |
publisher |
journal of geophysical research planets |
publishDate |
2013 |
url |
https://hdl.handle.net/20.500.11897/155604 https://doi.org/10.1002/jgre.20110 |
geographic |
South Pole |
geographic_facet |
South Pole |
genre |
South pole |
genre_facet |
South pole |
op_source |
SCI |
op_relation |
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS.2013,118,(8),1582-1608. 814857 2169-9097 http://hdl.handle.net/20.500.11897/155604 doi:10.1002/jgre.20110 WOS:000325007100002 |
op_doi |
https://doi.org/20.500.11897/155604 https://doi.org/10.1002/jgre.20110 |
container_title |
Journal of Geophysical Research: Planets |
container_volume |
118 |
container_issue |
8 |
container_start_page |
1582 |
op_container_end_page |
1608 |
_version_ |
1766202773546729472 |