ZY3-02 Laser Altimeter Footprint Geolocation Prediction

Area of Science:

• Geodesy
• Satellite Remote Sensing
• Optical Engineering

Background:

• The ZY3-02 satellite, launched in 2016, is China's first with a lightweight laser altimeter for surveying and mapping.
• Accurate calibration of the laser altimeter is essential for its operational use.
• Predicting laser footprint locations is a challenging first step in calibration due to the satellite's low sampling frequency and large footprint distance.

Purpose of the Study:

• To develop and validate a rigorous geometric prediction model for the ZY3-02 laser altimeter's on-orbit footprint location.
• To enhance the accuracy of laser altimeter calibration through precise geolocation prediction.
• To provide a reference for future land laser detector calibration.

Main Methods:

• An on-orbit rigorous geometric prediction model was established, referencing existing optical remote sensing satellite models.
• The model incorporates predictions of pointing angle, orbit parameters, and attitude angles.
• The model's effectiveness was verified through on-orbit geometric calibration tests of the ZY3-02 laser altimeter.

Main Results:

• Five laser footprint prediction experiments were performed using the developed model.
• The laser footprint prediction accuracy achieved was better than 150 meters on the ground.
• Test results confirmed the model's effectiveness and accuracy in predicting geolocation.

Conclusions:

• The proposed rigorous geometric prediction model accurately determines ZY3-02 laser altimeter footprint locations.
• The achieved accuracy of better than 150m supports precise on-orbit calibration.
• This method provides a valuable reference for future laser altimeter calibration missions.