Moon Image Acquisition for Pointing Calibration of LAPAN-A2 Satellite's High Resolution Camera

Abstract

The missions of LAPAN-A2 satellite are Earth observation using an RGB digital camera, maritime traffic monitoring, and amateur radio communications. The satellite carries a digital camera, to support the mission, with ground resolution 4 m and a swath width 7 km. It is necessary to do pointing calibration to measure misalignment between spacecraft's attitude sensors, spacecraft axis, and cameras, to make sure the accuracy of the camera pointing when capture the image. By using the inertial pointing method, that the satellite is controlled in three axis to direct the satellite camera to the Moon. Nevertheless, the field of view (FOV) of high-resolution digital cameras is very narrow, which is only 0.7° for the Moon to be fully visible in the camera frame. During image acquisition, the star sensor should be still able to see the star so the attitude information of spacecraft can be well determined. It means the time period and position for Moon acquisition is limited. By capturing multiple images, LAPAN-A2 satellite success to get the Moon images right in the center of the frame within the offset between camera and spacecraft axis are 0.1232° on the $x$ axis and −0.93° on the $y$ axis.