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High degree gravitational sensitivity from Mars orbiters for the GMM-1 gravity modelOrbital sensitivity of the gravity field for high degree terms (greater than 30) is analyzed on satellites employed in a Goddard Mars Model GMM-1, complete in spherical harmonics through degree and order 50. The model is obtained from S-band Doppler data on Mariner 9 (M9), Viking Orbiter 1 (VO1), and Viking Orbiter 2 (VO2) spacecraft, which were tracked by the NASA Deep Space Network on seven different highly eccentric orbits. The main sensitivity of the high degree terms is obtained from the VO1 and VO2 low orbits (300 km periapsis altitude), where significant spectral sensitivity is seen for all degrees out through degree 50. The velocity perturbations show a dominant effect at periapsis and significant effects out beyond the semi-latus rectum covering over 180 degrees of the orbital groundtrack for the low altitude orbits. Because of the wideband of periapsis motion covering nearly 180 degrees in w and +39 degrees in latitude coverage, the VO1 300 km periapsis altitude orbit with inclination of 39 degrees gave the dominant sensitivity in the GMM-1 solution for the high degree terms. Although the VO2 low periapsis orbit has a smaller band of periapsis mapping coverage, it strongly complements the VO1 orbit sensitivity for the GMM-1 solution with Doppler tracking coverage over a different inclination of 80 degrees.
Document ID
19940030486
Document Type
Technical Memorandum (TM)
Authors
Lerch, F. J. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Smith, D. E. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Chan, J. C. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Patel, G. B. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Chinn, D. S. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
September 6, 2013
Publication Date
May 1, 1994
Subject Category
GEOPHYSICS
Report/Patent Number
NASA-TM-104604
NAS 1.15:104604
REPT-94B00083
Funding Number(s)
PROJECT: RTOP 926-00-00
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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