The MODIS satellites operated by NASA started operation in 1999 with the launch of the Terra satellite and was followed by the launch of the Aqua satellite in 2002. The sensors are equipped with 36 bands in different wavelenghts and with different spatial resolutions (250, 500 and 1000 m). The two MODIS satellites each delivers one image per day of any location around the globe. This high temporal resolution makes it very attractive for monitoring programs. GRAS has a long time experience with applications of the MODIS sensors for marine monitoring, landcover and vegetation mapping, snow and ice cover mapping and several other applications.
The MERIS sensor onboard ENVISAT is operated by ESA and was launched in 2002. Like the MODIS satellites the MERIS provides data in different bands and with varying spatial resolution (300 and 1000 m). The ENVISAT is provided with 15 programmable bands in the visual and nearinfrared spectrum, which makes it very useful in marine monitoring applications. GRAS is using MERIS data in several marine monitoring programs around the globe, e.g. monitoring of suspended sediment, clorophyl-a etc. After loosing contact with the satellite on 8 April 2012, ESA formally announced the end of ENVISAT's mission on 9 may 2012.
||Meteosat Second Generation|
The Meteosat Second Generation (MSG) satellites are geostationary satellites delivering data in 12 channels with a spatial resolution of 3 km of the disc of the globe every 15th minute. This extremely high temporal resoultion data is primarily designed for meteological observations of the atmosphere, but other applications can be based on MSG data. GRAS has for instance experience with mapping the potential solar energy available in Western Africa.
The Suomi NPP satellite system was launched october 2011 and is intended to extend and improve upon the series of measurements initiated by the AVHRR and MODIS systems. The main system on Suomi NPP is the VIIRS radiometer that collects spectral information in 22 bands, with spatial resolutions varying between 375 and 750 m. The VIIRS system is cross disiplinary and is useful for varying subjects, such as marine monitoring and vegetational studies.