The Development of LAPAN-A3 Satellite Off-Nadir Imaging Mission

It is crucial for Indonesia as an agricultural country to have its own satellite image to be utilized in Indonesia’s resources monitoring. LAPAN-A3 satellite data has been studied for earth observation and can be utilized for monitoring paddy fields, built-up areas, forests, rivers, fishponds, shrubs, sea, agricultural lands, and bare soils. But, as a sun-synchronous satellite, LAPAN-A3 has demerit of little revisit time for one specific area. Therefore, off-nadir imaging becomes one essential trait of the satellite to increase target monitoring from 17 times to 71 times in a year. This paper aims to organize the development process of off-nadir strategy in acquiring target image in Indonesia. With two kinds of off-nadir maneuver, inertial pointing maneuver and wheel speed maneuver, LAPAN-A3 satellite can conduct off-nadir imaging up to 34.5˚ roll angle maneuver. Furthermore, wheel speed maneuver with roll angle and roll rate approach presents the improvement in time efficiency of the maneuver, from 1 hour and 35 minutes executing time in inertial pointing to 25 minutes in wheel speed maneuver, making it become promising candidate for time-constraint off-nadir imaging. Keywords—earth observation, satellite maneuver, off-nadir imaging