The Cassini VIMS archive of Titan: From browse products to global infrared color maps

S. Le Mouélic, T. Cornet, S. Rodriguez, C. Sotin, B. Seignovert, J. W. Barnes, Robert H. Brown, K. H. Baines, B. J. Buratti, R. N. Clark, P. D. Nicholson, J. Lasue, V. Pasek, J. M. Soderblom

Research output: Contribution to journalArticle

Abstract

We have analyzed the complete Visual and Infrared Mapping Spectrometer (VIMS) data archive of Titan. Our objective is to build global surface cartographic products, by combining all the data gathered during the 127 targeted flybys of Titan into synthetic global maps interpolated on a grid at 32 pixels per degree (∼1.4 km/pixel at the equator), in seven infrared spectral atmospheric windows. Multispectral summary images have been computed for each single VIMS cube in order to rapidly identify their scientific content and assess their quality. These summary images are made available to the community on a public website (vims.univ-nantes.fr). The global mapping work faced several challenges due to the strong absorbing and scattering effects of the atmosphere coupled to the changing observing conditions linked to the orbital tour of the Cassini mission. We determined a surface photometric function which accounts for variations in incidence, emergence and phase angles, and which is able to mitigate brightness variations linked to the viewing geometry of the flybys. The atmospheric contribution has been reduced using the subtraction of the methane absorption band wings, considered as proxies for atmospheric haze scattering. We present a new global three color composite map of band ratios (red: 1.59/1.27 µm; green: 2.03/1.27 µm; blue: 1.27/1.08 µm), which has also been empirically corrected from an airmass (the solar photon path length through the atmosphere) dependence. This map provides a detailed global color view of Titan's surface partially corrected from the atmosphere and gives a global insight of the spectral variability, with the equatorial dunes fields appearing in brownish tones, and several occurrences of bluish tones localized in areas such as Sinlap, Menvra and Selk craters. This kind of spectral map can serve as a basis for further regional studies and comparisons with radiative transfer outputs, such as surface albedos, and other additional data sets acquired by the Cassini Radar (RADAR) and Imaging Science Subsystem (ISS) instruments.

LanguageEnglish (US)
Pages121-132
Number of pages12
JournalIcarus
Volume319
DOIs
StatePublished - Feb 1 2019

Fingerprint

Titan
spectrometer
spectrometers
color
products
atmospheres
atmosphere
pixel
pixels
Cassini mission
scattering
atmospheric windows
dunes
dune field
websites
haze
multispectral image
equators
albedo
craters

Keywords

  • Image processing
  • Infrared observations
  • Titan
  • Titan surface

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Le Mouélic, S., Cornet, T., Rodriguez, S., Sotin, C., Seignovert, B., Barnes, J. W., ... Soderblom, J. M. (2019). The Cassini VIMS archive of Titan: From browse products to global infrared color maps. Icarus, 319, 121-132. https://doi.org/10.1016/j.icarus.2018.09.017

The Cassini VIMS archive of Titan : From browse products to global infrared color maps. / Le Mouélic, S.; Cornet, T.; Rodriguez, S.; Sotin, C.; Seignovert, B.; Barnes, J. W.; Brown, Robert H.; Baines, K. H.; Buratti, B. J.; Clark, R. N.; Nicholson, P. D.; Lasue, J.; Pasek, V.; Soderblom, J. M.

In: Icarus, Vol. 319, 01.02.2019, p. 121-132.

Research output: Contribution to journalArticle

Le Mouélic, S, Cornet, T, Rodriguez, S, Sotin, C, Seignovert, B, Barnes, JW, Brown, RH, Baines, KH, Buratti, BJ, Clark, RN, Nicholson, PD, Lasue, J, Pasek, V & Soderblom, JM 2019, 'The Cassini VIMS archive of Titan: From browse products to global infrared color maps' Icarus, vol. 319, pp. 121-132. https://doi.org/10.1016/j.icarus.2018.09.017
Le Mouélic S, Cornet T, Rodriguez S, Sotin C, Seignovert B, Barnes JW et al. The Cassini VIMS archive of Titan: From browse products to global infrared color maps. Icarus. 2019 Feb 1;319:121-132. https://doi.org/10.1016/j.icarus.2018.09.017
Le Mouélic, S. ; Cornet, T. ; Rodriguez, S. ; Sotin, C. ; Seignovert, B. ; Barnes, J. W. ; Brown, Robert H. ; Baines, K. H. ; Buratti, B. J. ; Clark, R. N. ; Nicholson, P. D. ; Lasue, J. ; Pasek, V. ; Soderblom, J. M. / The Cassini VIMS archive of Titan : From browse products to global infrared color maps. In: Icarus. 2019 ; Vol. 319. pp. 121-132.
@article{ce21b602dfa64bcbbeaee87644b82260,
title = "The Cassini VIMS archive of Titan: From browse products to global infrared color maps",
abstract = "We have analyzed the complete Visual and Infrared Mapping Spectrometer (VIMS) data archive of Titan. Our objective is to build global surface cartographic products, by combining all the data gathered during the 127 targeted flybys of Titan into synthetic global maps interpolated on a grid at 32 pixels per degree (∼1.4 km/pixel at the equator), in seven infrared spectral atmospheric windows. Multispectral summary images have been computed for each single VIMS cube in order to rapidly identify their scientific content and assess their quality. These summary images are made available to the community on a public website (vims.univ-nantes.fr). The global mapping work faced several challenges due to the strong absorbing and scattering effects of the atmosphere coupled to the changing observing conditions linked to the orbital tour of the Cassini mission. We determined a surface photometric function which accounts for variations in incidence, emergence and phase angles, and which is able to mitigate brightness variations linked to the viewing geometry of the flybys. The atmospheric contribution has been reduced using the subtraction of the methane absorption band wings, considered as proxies for atmospheric haze scattering. We present a new global three color composite map of band ratios (red: 1.59/1.27 µm; green: 2.03/1.27 µm; blue: 1.27/1.08 µm), which has also been empirically corrected from an airmass (the solar photon path length through the atmosphere) dependence. This map provides a detailed global color view of Titan's surface partially corrected from the atmosphere and gives a global insight of the spectral variability, with the equatorial dunes fields appearing in brownish tones, and several occurrences of bluish tones localized in areas such as Sinlap, Menvra and Selk craters. This kind of spectral map can serve as a basis for further regional studies and comparisons with radiative transfer outputs, such as surface albedos, and other additional data sets acquired by the Cassini Radar (RADAR) and Imaging Science Subsystem (ISS) instruments.",
keywords = "Image processing, Infrared observations, Titan, Titan surface",
author = "{Le Mou{\'e}lic}, S. and T. Cornet and S. Rodriguez and C. Sotin and B. Seignovert and Barnes, {J. W.} and Brown, {Robert H.} and Baines, {K. H.} and Buratti, {B. J.} and Clark, {R. N.} and Nicholson, {P. D.} and J. Lasue and V. Pasek and Soderblom, {J. M.}",
year = "2019",
month = "2",
day = "1",
doi = "10.1016/j.icarus.2018.09.017",
language = "English (US)",
volume = "319",
pages = "121--132",
journal = "Icarus",
issn = "0019-1035",
publisher = "Academic Press Inc.",

}

TY - JOUR

T1 - The Cassini VIMS archive of Titan

T2 - Icarus

AU - Le Mouélic, S.

AU - Cornet, T.

AU - Rodriguez, S.

AU - Sotin, C.

AU - Seignovert, B.

AU - Barnes, J. W.

AU - Brown, Robert H.

AU - Baines, K. H.

AU - Buratti, B. J.

AU - Clark, R. N.

AU - Nicholson, P. D.

AU - Lasue, J.

AU - Pasek, V.

AU - Soderblom, J. M.

PY - 2019/2/1

Y1 - 2019/2/1

N2 - We have analyzed the complete Visual and Infrared Mapping Spectrometer (VIMS) data archive of Titan. Our objective is to build global surface cartographic products, by combining all the data gathered during the 127 targeted flybys of Titan into synthetic global maps interpolated on a grid at 32 pixels per degree (∼1.4 km/pixel at the equator), in seven infrared spectral atmospheric windows. Multispectral summary images have been computed for each single VIMS cube in order to rapidly identify their scientific content and assess their quality. These summary images are made available to the community on a public website (vims.univ-nantes.fr). The global mapping work faced several challenges due to the strong absorbing and scattering effects of the atmosphere coupled to the changing observing conditions linked to the orbital tour of the Cassini mission. We determined a surface photometric function which accounts for variations in incidence, emergence and phase angles, and which is able to mitigate brightness variations linked to the viewing geometry of the flybys. The atmospheric contribution has been reduced using the subtraction of the methane absorption band wings, considered as proxies for atmospheric haze scattering. We present a new global three color composite map of band ratios (red: 1.59/1.27 µm; green: 2.03/1.27 µm; blue: 1.27/1.08 µm), which has also been empirically corrected from an airmass (the solar photon path length through the atmosphere) dependence. This map provides a detailed global color view of Titan's surface partially corrected from the atmosphere and gives a global insight of the spectral variability, with the equatorial dunes fields appearing in brownish tones, and several occurrences of bluish tones localized in areas such as Sinlap, Menvra and Selk craters. This kind of spectral map can serve as a basis for further regional studies and comparisons with radiative transfer outputs, such as surface albedos, and other additional data sets acquired by the Cassini Radar (RADAR) and Imaging Science Subsystem (ISS) instruments.

AB - We have analyzed the complete Visual and Infrared Mapping Spectrometer (VIMS) data archive of Titan. Our objective is to build global surface cartographic products, by combining all the data gathered during the 127 targeted flybys of Titan into synthetic global maps interpolated on a grid at 32 pixels per degree (∼1.4 km/pixel at the equator), in seven infrared spectral atmospheric windows. Multispectral summary images have been computed for each single VIMS cube in order to rapidly identify their scientific content and assess their quality. These summary images are made available to the community on a public website (vims.univ-nantes.fr). The global mapping work faced several challenges due to the strong absorbing and scattering effects of the atmosphere coupled to the changing observing conditions linked to the orbital tour of the Cassini mission. We determined a surface photometric function which accounts for variations in incidence, emergence and phase angles, and which is able to mitigate brightness variations linked to the viewing geometry of the flybys. The atmospheric contribution has been reduced using the subtraction of the methane absorption band wings, considered as proxies for atmospheric haze scattering. We present a new global three color composite map of band ratios (red: 1.59/1.27 µm; green: 2.03/1.27 µm; blue: 1.27/1.08 µm), which has also been empirically corrected from an airmass (the solar photon path length through the atmosphere) dependence. This map provides a detailed global color view of Titan's surface partially corrected from the atmosphere and gives a global insight of the spectral variability, with the equatorial dunes fields appearing in brownish tones, and several occurrences of bluish tones localized in areas such as Sinlap, Menvra and Selk craters. This kind of spectral map can serve as a basis for further regional studies and comparisons with radiative transfer outputs, such as surface albedos, and other additional data sets acquired by the Cassini Radar (RADAR) and Imaging Science Subsystem (ISS) instruments.

KW - Image processing

KW - Infrared observations

KW - Titan

KW - Titan surface

UR - http://www.scopus.com/inward/record.url?scp=85053809000&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85053809000&partnerID=8YFLogxK

U2 - 10.1016/j.icarus.2018.09.017

DO - 10.1016/j.icarus.2018.09.017

M3 - Article

VL - 319

SP - 121

EP - 132

JO - Icarus

JF - Icarus

SN - 0019-1035

ER -