[M-SD39] Micro-satellite and its constellation in remote sensing

[MSD39-01] In Orbit Performance of Diwata-2

*Shielo Namuco Muta¹, Francisco Miguel Felicio², Matthew Medrano², Gay Jane Perez Perez^1,2, Alvin Retamar⁵, Joel Joseph Marciano^3,1, Tetsuro Ishida⁴, Yukihiro Takahashi⁴ (1.Philippine Space Agency, 2.Institute of Environmental Science and Meteorology, University of the Philippines Diliman, 3.EEEI, University of the Philippines Diliman, 4.Space Mission Center, Hokkaido University, 5.Advanced Science and Technology Institute, Department of Science and Technology)

Keywords:Diwata-2 , In orbit operations, microsatellite

Diwata-2 is the Philippines’ second microsatellite and has been in successful operation for more than two years. It was launched in 2018 via H-IIA rocket from Tanegashima, Japan from where it was brought to an orbital altitude of 600 km. Its sun synchronous orbit enables the satellite to have frequent revisit of 31 days at nadir. It carries five optical payloads, primarily using a Spaceborne Multispectral Imager (SMI), Enhanced Resolution Camera (ERC), and High Precision Telescope (HPT) for routine captures intended for environmental monitoring and assessment. Since its launch, the microsatellite has carried out more than 425 acquisition attempts over the Philippines, covering roughly 82.83% of the country’s land area via SMI. When monitoring weather disturbances, the satellite uses its Wide Field Camera (WFC) whose broad field of view enables the capture of the typhoon in its entirety. Enhanced Resolution Camera (ERC) is utilized simultaneously in these situations to capture storm cloud formations. Diwata-2 has also been operating emergency communications in times of disaster. Using satellite’s onboard Amateur Radio Unit (ARU), ham radio users can relay messages from anywhere within the Philippines and up to nearby countries. Diwata-2 boasts a significant improvement in its attitude control compared to its predecessor, Diwata-1, having a target pointing accuracy of 0.66 degrees. Communication to the satellite is done using the Ground Receiving Stations located in the Advanced Science and Technology Institute and Tohoku University. This paper intends to give an overview of how satellite Diwata-2 is operated as well as the lessons learned from the country’s second microsatellite. Diwata-2 is expected to continue its mission until 2023.