Orbit Determination of Korean GEO Satellite Using Single SLR Sensor

Area of Science:

• Space Science
• Geodesy
• Satellite Technology

Background:

• Geostationary Earth Orbit (GEO) satellite orbit determination (OD) relies on ground-based radar, with expected precision under 1 km.
• Satellite Laser Ranging (SLR) is adopted as a subsidiary method for the Korea Multi-Purpose Satellite (KOMPSAT)-2B (GK-2B) to enhance OD accuracy.
• Observing GEO satellites with SLR presents challenges due to limited time, equipment, and potential sensor damage from lasers.

Purpose of the Study:

• To mitigate challenges in using SLR for GK-2B orbit determination.
• To improve the orbit precision of GK-2B using SLR data from a single domestic station.
• To assess the feasibility and accuracy of SLR-based OD for geostationary satellites.

Main Methods:

• Numerical SLR data analysis was performed using a Chinese GEO navigation satellite (Compass-G1) and a Chinese SLR station in Changchun.
• Two OD scenarios were evaluated based on varying numbers of daily SLR observations.
• Orbit determination was verified by comparing results with external precise ephemeris data from the GeoForschungsZentrum (GFZ).

Main Results:

• Orbit determination for GK-2B achieved a 3D position error of 24.01 m with 13 observations per day and 43.46 m with 9 observations per day.
• Independent verification using Compass-G1 and Changchun SLR data yielded a 3D error of 31.89 m, favorable against GFZ precise ephemeris.
• The study demonstrates that OD based on a single SLR station is applicable for estimating geostationary satellite orbits within a 100 m accuracy.

Conclusions:

• Single-station SLR tracking is a viable method for enhancing the orbit determination of geostationary satellites like GK-2B.
• SLR provides a complementary and valuable data source for improving the precision of satellite orbit determination.
• The findings support the use of SLR for precise orbit estimation, crucial for meteorological and ocean monitoring missions.