First light image from the Cloud Profiling Radar instrument on EarthCARE satellite. Captured east of Japan on 13th June 2024. Image credit:
JAXA/NICT/ESA
Focusing this week on the successful launch of the Japanese Advanced Land Observing Satellite-4, together with the first light image from the recently launched EarthCARE satellite.
Launch
The start of the month saw the successful launch of an Earth Observation (EO) satellite by the Japan Aerospace Exploration Agency (JAXA). The Advanced Land Observing Satellite-4 (ALOS-4), also known as DAICHI-4, was put into a sun-synchronous orbit at an altitude of approximately 628 kilometres by the Japanese H3 Rocket from the Tanegashima Space Center.
The ALOS-4 satellite carries Phased-Array L-band Synthetic Aperture Radar– 3 (PALSAR-3) instrument and has three modes:
- Stripmap mode offers a spatial resolution ranging from 3 m to 10 m, with a swath width of between 100-200 km
- ScanSAR mode will have a spatial resolution of 25 m and a swath width of 700 km
- Spotlight mode will have a spatial resolution of 3 m x 1 m and a swath width of 35 km.
The measurement data collected from the satellite will include:
- Soil moisture, vegetation monitoring, land albedo and reflectance, and landscape topography
- Ocean surface winds
- Snow and sea ice cover, edge and thickness, together with ice sheet topography
- Atmospheric winds & gravity, magnetic and geodynamic measurements
The satellite, built by Mitsubishi Electric Corporation, is expected to provide data for applications including environmental monitoring, agriculture and forestry, land surface use, disaster monitoring and civil planning. Although it is predominantly a land observation mission, it will also significantly contribute to ocean observations.
This was the third launch of the H3 rocket. Its inaugural launch in March 2023 failed due to a second-stage engine issue, which led to the loss of the ALOS-3 satellite, although there was a successful second flight earlier this year.
Light
The EarthCARE satellite has issued its first light image following its launch at the end of May, which we covered in a blog. The image was taken by the Cloud profiling radar (CPR) instrument, developed by Japan Aerospace Exploration Agency & Japan’s National Institute of Information and Communications Technology.
This exciting image, shown at the top of the blog, shows the internal structure of clouds over the ocean, east of Japan on 13th June 2024. The image has two parts, with the left-hand side showing the vertically-resolved concentration of cloud particles measured as radar reflectivity, with the denser part of the cloud in the centre where the particles are larger. On the right-hand side, the ice crystals and snowflakes are suspended in the atmosphere with little vertical motion. There is a clear boundary line in both images at around 5 kilometres, where the ice and snow, in the upper layer, melt, to form water droplets that then fall as rain.
The first images from the other three instruments onboard EarthCARE are expected in the coming weeks and months. Once all four are operational and working together, the mission should provide a holistic view of the interactions between clouds, aerosols, incoming solar radiation and outgoing thermal radiation, which will help scientists improve their climate and numerical models to better understand climate change, rising temperatures and improve predictions of future climate trends.
Conclusion
It is really exciting to see the first light image from EarthCARE, and we can’t wait to see what will be produced when all four instruments work together. Coupled with the last EO launch, this shows that the sector is a fast-moving, innovative, and exciting field to work in!
