Advanced Land Observing Satellite-4 “DAICHI-4” (ALOS-4) SPAISE3 Antenna Deployment

The Japan Aerospace Exploration Agency (JAXA) confirmed that the deployment of the SPAISE3^*1 antenna was successfully performed by receiving telemetry from the Advanced Land Observing Satellite-4 “DAICHI-4” (ALOS-4).
The following is an image after the deployment of the SPAISE3 antenna of DAICHI-4 received at the JAXA Mingenew station in Australia at 2:07 on July 3, 2024 (JST).
SPAISE3 was developed by JAXA and NEC Corporation.

* 1: SPAISE3 (Space-based Automatic Identification System Experiment3) is an instrument that receives
Automatic Identification System (AIS) signals transmitted from vessels. The AIS signal contains
information such as vessel type and position and is transmitted from almost all vessels over 300 tons,
helping to prevent maritime accidents.
Satellites can receive AIS signals over a wide area. However, there are challenges, because in areas
with a high density of ships, the radio waves overlap and cannot be received. This problem is addressed
by demonstrating countermeasure technology in SPAISE3.
DAICHI-4’s radar observation can monitor even vessels which do not transmit AIS signals. By combining information received from both the radar and SPAISE3, it is expected to be useful in
understanding the oceanic situation around Japan.

Please refer to the link below about satellite mounted AIS.
MDA：Maritime Domain Awareness by satellite
https://earth.jaxa.jp/en/application/mda/index.html

<Movie of DAICHI-4 SPAISE3 Antenna Deployment>
▶ DAICHI-4 (ALOS-4) CG movie
https://www.youtube.com/watch?v=lzMONfjs-Ew

Upcoming announcement (JAXA press release) schedule (JST) *Please note that posting times are subject to change depending on operational conditions. 9:30 July 3, 2024 – Completion of Critical Operations Phase, Advanced Land Observing Satellite-4 “DAICHI-4” (ALOS-4)

<Conceptual Diagram of Before SPAISE3 Antenna Deployment>

<Conceptual Diagram of After Deployment of SPAISE3 Antenna Captured by the Deployment Confirmation Monitor Camera>

★ Mitsubishi Electric Corporation is in charge of design and manufacturing as the prime contractor and is supporting the initial operations conducted by JAXA.

【Related Site】
Mitsubishi Electric Corporation Space Systems Website:
https://www.mitsubishielectric.com/bu/space/index.html

NEC Corporation:
https://www.necam.com/

JAXA DAICHI-4 (ALOS-4) Project Page:
https://global.jaxa.jp/projects/sat/alos4/