PDS: The Planetary Atmospheres Node
Electron density profiles from Viking Orbiter 1 on orbits 289 (black), 523 (grey), and 755 (red) (left) and on orbits 490 (black), 508 (grey), and 523 (red) (right). The vertical blue line indicates zero.
Introduction
Viking Orbiters 1 and 2 conducted radio occultations at Mars from 1976 to 1978 (Lindal et al., 1979; Kliore, 1992). Viking Orbiter 2 ceased operations in July 1978. Although Viking Orbiter 1 continued operations until August 1980, no further radio occultation measurements were collected.
These Viking data products were derived from Mars ionospheric electron density profiles retrieved by Paul Withers from Tamara Breus (Breus et al., 1998a,b). Detailed comparison with existing published profiles was utilized to verify the restoration.
These data have not been supplanted by later missions. Compared to the Mars Global Surveyor data, these data have better sensitivity, higher vertical extent, greater global coverage and larger solar zenith angle coverage.
References
Lindal, G. F., et al., (1979), Viking radio occultation measurements of the atmosphere and topography of Mars - Data acquired during 1 Martian year of tracking,J. Geophys. Res.,84, 8443–8456, doi:10.1029/JB084iB14p08443.
Kliore, A. J. (1992), Radio occultation observations of the ionospheres of Mars and Venus,inVenus and Mars: Atmospheres, ionospheres, and solar wind interactions, GeophysicalMonograph Series, vol. 66, pp. 265–276, American Geophysical Union, Washington, DC.
Breus, T. K., et al.(1998a), Conditions in the Martian ionosphere/atmosphere from a comparison of a thermospheric model with radio occultation data, Planet. Space Sci., 46, 367–376, doi: 10.1016/S0032-0633(97)00168-2.
Breus, T. K., et al. (1998b), Application of Viking radio occultation data to the future studies of the Martian ionosphere, Adv. Space Res., 22, 463–470, doi:10.1016/S0273-1177(98)00087-8.
Summary of Data
The data consists of 73 profiles ranging in latitude from -68° to 74° including equatorial values. Longitudinally the data span the planet. Solar Zenith Angles range from 49° to 95°.
User's Guide
Accessing the data
Each data file is specified by a unique identifier (urn). Utilizing these identifiers and the index (CSV) allows retrieval of data at the file level.
Downloading the data
Citing Datasets for Publications
P. Withers (2020), Viking Orbiters 1 and 2 Radio Occultation Electron Density, NASA Planetary Data System, https://doi.org/10.17189/1518930.
Viking Orbiters 1 and 2 conducted radio occultations at Mars from 1976 to 1978 (Lindal et al., 1979; Kliore, 1992). Viking Orbiter 2 ceased operations in July 1978. Although Viking Orbiter 1 continued operations until August 1980, no further radio occultation measurements were collected.
These Viking data products were derived from Mars ionospheric electron density profiles retrieved by Paul Withers from Tamara Breus (Breus et al., 1998a,b). Detailed comparison with existing published profiles was utilized to verify the restoration.
These data have not been supplanted by later missions. Compared to the Mars Global Surveyor data, these data have better sensitivity, higher vertical extent, greater global coverage and larger solar zenith angle coverage.
References
Lindal, G. F., et al., (1979), Viking radio occultation measurements of the atmosphere and topography of Mars - Data acquired during 1 Martian year of tracking,J. Geophys. Res.,84, 8443–8456, doi:10.1029/JB084iB14p08443.
Kliore, A. J. (1992), Radio occultation observations of the ionospheres of Mars and Venus,inVenus and Mars: Atmospheres, ionospheres, and solar wind interactions, GeophysicalMonograph Series, vol. 66, pp. 265–276, American Geophysical Union, Washington, DC.
Breus, T. K., et al.(1998a), Conditions in the Martian ionosphere/atmosphere from a comparison of a thermospheric model with radio occultation data, Planet. Space Sci., 46, 367–376, doi: 10.1016/S0032-0633(97)00168-2.
Breus, T. K., et al. (1998b), Application of Viking radio occultation data to the future studies of the Martian ionosphere, Adv. Space Res., 22, 463–470, doi:10.1016/S0273-1177(98)00087-8.
Summary of Data
The data consists of 73 profiles ranging in latitude from -68° to 74° including equatorial values. Longitudinally the data span the planet. Solar Zenith Angles range from 49° to 95°.
User's Guide
Accessing the data
Each data file is specified by a unique identifier (urn). Utilizing these identifiers and the index (CSV) allows retrieval of data at the file level.
Downloading the data
Citing Datasets for Publications
P. Withers (2020), Viking Orbiters 1 and 2 Radio Occultation Electron Density, NASA Planetary Data System, https://doi.org/10.17189/1518930.
