[M-SD35] Future Missions of Satellite Earth Observation

[MSD35-P03] Technical Demonstration of the Next-Generation Precipitation Radar - Application to a Scanning Doppler Radar -

*Nobuhiro Takahashi¹, Daisuke Joudoi², Kenji Nakamura³, Tomoo Ushio⁴, Kousuke Yamamoto², Moeka Yamaji², Takuji Kubota², kanae Haze², Hidekazu Masuda², Kaya Kanemaru⁵ (1.Institute for Space-Earth Environmental Research, Nagoya University, 2.Japan Aerospace Exploration Agency, 3.Dokkyo University, 4.Osaka University, 5.National Institute of Information and Communications Technology)

Keywords:Earth Observation Satellite, Doppler radar, geostationary satellite

This proposal is a continuation of the previous call for proposals, and aims to demonstrate the technology for future precipitation radar observations from geostationary orbit. To date, we have investigated deployable planar antennas as a basic technology, and have produced a prototype of the antenna deployment mechanism and confirmed its performance in ground tests. Furthermore, the launch of the DEployable LIGHtweight planar antenna Technology demonstration (DELIGHT) mission, which aims to demonstrate the antenna deployment mechanism in orbit, is planned for JFY2025 using the HTV-X No. 1. For measuring Doppler velocity in the nadir direction, EarthCARE/CPR has been launched in 2024, and development of PMM/KuDPR has also begun. KuDPR will introduce DPCA (displaced phase center antenna) technology, which uses two antennas in the direction of flight, to reduce the Doppler velocity error associated with the satellite's high-speed movement. As a result, in the future, it is expected that technology will be developed to acquire Doppler velocity not only in the nadir direction but also in the horizontal direction, and in this proposal, we will also investigate horizontal Doppler velocity measurement as an application of the deployable antenna that we have been considering. We will also investigate ways to reduce costs.
As mentioned above, the launch of DELIGHT is planned for 2025, and we can expect to see evaluations mainly related to antenna deployment technology. In addition, for the scanning Doppler radar, issues such as manufacturing technology and energy distribution have been pointed out regarding the use of waveguide slot antennas of different lengths that were considered last year, so we will reconsider this and also consider a two-dimensional phased array system using a deployable antenna.