Geodetic constraints from multi-beam laser altimeter crossovers
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The round-trip travel time measurements made by spacecraft laser altimeters are primarily used to construct topographic maps of the target body. The accuracy of the calculated bounce point locations of the laser pulses depends on the quality of the spacecraft trajectory reconstruction. The trajectory constraints from Doppler and range radio tracking data can be supplemented by altimetric “crossovers”, to greatly improve the reconstruction of the spacecraft trajectory. Crossovers have been used successfully in the past (e.g., Mars Orbiter Laser Altimeter on Mars Global Surveyor), but only with single-beam altimeters. The same algorithms can be used with a multi-beam laser altimeter, but we present a method using the unique cross-track topographic information present in the multi-beam data. Those crossovers are especially adapted to shallow (small angle) intersections, as the overlapping area is large, reducing the inherent ambiguities of single-beam data in that situation. We call those “swath crossovers”. They prove particularly useful in the case of polar-orbiting spacecraft over slowly rotating bodies, because all the non-polar crossovers have small intersection angles. To demonstrate this method, we perform a simplified simulation based on the Lunar Reconnaissance Orbiter (LRO) and its five-beam Lunar Orbiter Laser Altimeter. We show that swath crossovers over one lunar month can independently, from geometry alone, recover the imposed orbital perturbations with great accuracy (5 m horizontal, < 1 m vertical, about one order of magnitude smaller than the imposed perturbations). We also present new types of constraints that can be derived from the swath crossovers, and designed to be used in a precision orbit determination setup. In future work, we will use such multi-beam altimetric constraints with data from LRO.
KeywordsLaser altimeter Crossover Orbit determination Moon Multi-beam
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- Chin G, Brylow S, Foote M, Garvin J, Kasper J, Keller J, Litvak M, Mitrofanov I, Paige D, Raney K, Robinson M, Sanin A, Smith D, Spence H, Spudis P, Stern SA, Zuber M (2007) Lunar reconnaissance orbiter overview: the instrument suite and mission. Space Sci Rev. doi: 10.1007/s11214-007-9153-y
- Ivanov BA, Neukum G, Bottke WF, Hartmann WK (2002) The comparison of size-frequency distributions of impact craters and asteroids and the planetary cratering rate. In: Bottke WF, Cellino A, Paolicchi P, Binzel R, Arizona U (eds) Asteroids III, pp 89–101Google Scholar
- Namiki N, Iwata T, Matsumoto K, Hanada H, Noda H, Goossens S, Ogawa M, Kawano N, Asari K, Tsuruta S, Ishihara Y, Liu Q, Kikuchi F, Ishikawa T, Sasaki S, Aoshima C, Kurosawa K, Sugita S, Takano T (2009) Farside gravity field of the moon from four-way Doppler measurements of SELENE (Kaguya). Science 323(5916): 900–905. doi: 10.1126/science.1168029 CrossRefGoogle Scholar
- Pavlis DE, Poulose SG, McCarthy JJ (2006) GEODYN operations manuals, contractor report. SGT Inc Greenbelt, MarylandGoogle Scholar
- Smith DE, Zuber MT, Frey HV, Garvin JB, Head JW, Muhleman DO, Pettengill GH, Phillips RJ, Solomon SC, Zwally HJ, Banerdt WB, Duxbury TC, Golombek MP, Lemoine FG, Neumann GA, Rowlands DD, Aharonson O, Ford PG, Ivanov AB, Johnson CL, McGovern PJ, Abshire JB, Afzal RS, Sun X (2001) Mars Orbiter Laser Altimeter: experiment summary after the first year of global mapping of Mars. J Geophys Res 106(E10): 23689–23722CrossRefGoogle Scholar
- Smith DE, Zuber MT, Jackson GB, Cavanaugh JF, Neumann GA, Riris H, Sun X, Zellar RS, Coltharp C, Connelly J, Katz RB, Kleyner I, Liiva P, Matuszeski A, Mazarico E, McGarry JF, Novo-Gradac A-M, Ott MN, Peters C, Ramos-Izquierdo LA, Ramsey L, Rowlands DD, Schmidt S, Scott III VS, Shaw GB, Smith JC, Swinski J-P, Torrence MH, Unger G, Yu AW, Zagwodzki TW (2009) The Lunar Orbiter Laser Altimeter investigation on the Lunar Reconnaissance Orbiter mission. Space Sci Rev. doi: 10.1007/s11214-009-9512-y
- Zuber MT, Smith DE, Zellar RS, Neumann GA, Sun X, Katz RB, Kleyner I, Matuszeski A, McGarry JF, Ott MN, Ramos-Izquierdo LA, Rowlands DD, Torrence MH, Zagwodzki TW (2009) The Lunar Reconnaissance Orbiter laser ranging investigation. Space Sci Rev. doi: 10.1007/s11214-009-9511-z