Ariane 5 carrying JCSAT-17 and Geo-Kompsat-2B, on 18/02/20. Image courtesy of ESA/CNE/Arianespace; Photo Optique VidĂ©o CSG – P Piron.
The latest Indian Earth Observation satellite due be launched was going to be Geo Imaging Satellite-1 (GISAT-1). The Indian Space Research Organisation (ISRO) is expecting to put the satellite into orbit on the 5th March 2020 via the Geosynchronous Satellite Launch Vehicle (GSLV-F10) from the Satish Dhawan Space Centre in Sriharikota. However, the launch was postponed for technical reasons and a revised date is still be confirmed.
Once launched, GISAT-1 will go into a geostationary orbit at approximately 36,000 km and will image the entire Indian subcontinent every 30 minutes. The satellite carries four imagers:
- Multi-spectral Visible Near-Infrared imager with six spectral bands and a 50 km spatial resolution.
- Multispectral – Long Wave Infrared imager with six spectral bands and a 1.5 km spatial resolution
- Hyperspectral Imager with 158 bands in visible and near infra-red and a 318 metres spatial resolution
- Hyperspectral Imager with 256 bands hyper-spectral short wave infra-red bands with 191 metres spatial resolution.
In addition, GISAT also carries a 700 mm telescope based on the design of Cartosat 2. GISAT-1, with an anticipated life of 7 years, is part of a pair of satellites and GISAT-2 to be launched later.
Being a geostationary satellite it’s expected to provide near-real-time imagery to support applications in agriculture, forestry, mineralogy, natural disasters, cloud properties, snow, glaciers and oceanography. Geostationary satellites are in a much higher orbit than polar-orbiting satellites, which are designed to build up a picture of the whole of the Earth over a few days. Geostationary is a subset of geosynchronous satellites – they maintain their position over a fixed location on the Earth and so are very useful when a country wants to continuously image a particular view of the Earth; images can be acquired as frequently as every 5 minutes. Most geostationary satellites are focused on collecting metrological data, with South Korea pioneering their use for marine applications.
The Korea Aerospace Research Institute’s (KARI) GEO-KOMPSAT-2B satellite was put into orbit on 19th February on board the Ariane 5 rocket from the French Guiana Space Centre.
GEO-KOMPSAT-2B has gone into a geostationary orbit above South Korea at an altitude of just under 36 000 km. It’s an ocean and environmental monitoring mission with two instruments:
- GOCI-II (Geostationary Ocean Colour Imager-Follow On) – This is a moderate resolution optical imager with 13 bands including ultra-violet, visible, near infra-red and a panchromatic band, and it has a spatial resolution of 250 m. It focuses on measuring ocean colour and aerosols.
- GEMS (Geostationary Environmental Monitoring Spectrometer) – This is a whiskbroom instrument in the ultra-violet and visible range, operating with a 5 km spatial resolution. It is focussing on measuring ozone profiles and other atmospheric pollutants.
Like GiSAT-1, GEO-KOMPSAT-2B is one-half of a pair of satellites. GEO-KOMPSAT-2A focuses on metrological monitoring and was launched on the 4th December 2018. Both satellites are expected to have a mission life of at least ten years.
Finally, three weeks ago we highlighted the potential for the UK to have access to the Galileo Public Regulated Service (PRS) as part of the Brexit trade negotiations and wondered what impact it might have on the proposed UK GNSS development the feasibility of which was due to report back this month.
Interestingly, the Financial Times reported earlier this week that the project has been put on hold. Although not apparently linked to the EU’s offer, it appears that increasing costs, concern over the viability of a global solution and a lack of clarity over user requirements are the reasons behind the delay. It will be interesting to see how this plays out over the coming weeks and months.
