TY - GEN

T1 - Simulation of precise orbit determination of COSMIC from onboard GPS zero-difference phase data with kinematic method

AU - Guo, Jinyun

AU - Hwang, Chein-way

AU - Tseng, Zipang

AU - Chang, Xiaotao

PY - 2007/12/1

Y1 - 2007/12/1

N2 - COSMIC is a constellation mission to study the climate, ionosphere and geodesy. The main geodetic mission of COSMIC is to determine the global gravity field model and its temporal variations, which need the precise geometric orbit of COSMIC. GPS observations onboard COSMIC are simulated using the GPS precise final orbit and high-rate clock of CODE, the designed orbit of COSMIC and the GPS antennae for precise orbit determination (POD). The precise geometric orbits of COSMIC are determined with the kinematic method from the space-borne simulated observations to test the POD capability of GPS antennae. There are two POD GPS antennae onboard COSMIC, named as POD +X and -X. The orbit from POD -X antenna has the approximately same precision as that from POD +X antenna, and the errors of both are greater than the given random error while simulating GPS data. The main reason is that the designed positions of POD antennae are not good. There are the different angels between the boresight vector and zenith direction of two antennae. Another reason is that POD +X antenna is in the flying direction and POD -X antenna is in the inverse direction. In order to get the high precision of POD, a virtual antenna is constructed from POD +X and -X, whose center is the center of mass of COSMIC. Observations from POD +X and -X then are reduced to the virtual antenna. Comparing with the referenced orbit and the kinematic orbit from the virtual antenna, the precision of orbit is consistent to the given random error when simulating GPS data, up to centimeter level.

AB - COSMIC is a constellation mission to study the climate, ionosphere and geodesy. The main geodetic mission of COSMIC is to determine the global gravity field model and its temporal variations, which need the precise geometric orbit of COSMIC. GPS observations onboard COSMIC are simulated using the GPS precise final orbit and high-rate clock of CODE, the designed orbit of COSMIC and the GPS antennae for precise orbit determination (POD). The precise geometric orbits of COSMIC are determined with the kinematic method from the space-borne simulated observations to test the POD capability of GPS antennae. There are two POD GPS antennae onboard COSMIC, named as POD +X and -X. The orbit from POD -X antenna has the approximately same precision as that from POD +X antenna, and the errors of both are greater than the given random error while simulating GPS data. The main reason is that the designed positions of POD antennae are not good. There are the different angels between the boresight vector and zenith direction of two antennae. Another reason is that POD +X antenna is in the flying direction and POD -X antenna is in the inverse direction. In order to get the high precision of POD, a virtual antenna is constructed from POD +X and -X, whose center is the center of mass of COSMIC. Observations from POD +X and -X then are reduced to the virtual antenna. Comparing with the referenced orbit and the kinematic orbit from the virtual antenna, the precision of orbit is consistent to the given random error when simulating GPS data, up to centimeter level.

KW - COSMIC

KW - GPS zero-difference phase data

KW - Precise kinematic orbit determination

KW - Virtual antenna

UR - http://www.scopus.com/inward/record.url?scp=42949138259&partnerID=8YFLogxK

U2 - 10.1117/12.773977

DO - 10.1117/12.773977

M3 - Conference contribution

AN - SCOPUS:42949138259

SN - 9780819469601

T3 - Proceedings of SPIE - The International Society for Optical Engineering

BT - Second International Conference on Space Information Technology

Y2 - 10 November 2007 through 11 November 2007

ER -