The space segment, in charge of developing and launching the technically challenging EnMAP satellite, is led by OHB System AG. It covers the following mission aspects:
- Building the satellite bus
- Developing and manufacturing the payload: a sophisticated hyperspectral instrument
- Integrating and testing the entire satellite
- Procuring a flight opportunity, including launch support and preparation, and the launch itself.
The hyperspectral imager is a push-broom type consisting of two prism imaging spectrometers: one for the VNIR and one for the SWIR range. They share a common three-mirror anastigmat telescope with a field splitter placed in the telescope focal plane. In order to achieve a high signal-to-noise ratio, detectors and front-end electronics are being developed with low noise and high quantum efficiency characteristics. The SWIR detector is actively cooled to 150 K using a pulse tube cooler. The VNIR detector is thermally controlled to ±0.1 K by means of thermoelectric cooling.
Orbit and Communication
The sensors cover a swath width of 30 km with a ground sampling distance of 30 m × 30 m. The along-track dimension is given by the satellite movement. Data length up to 5000 km can be collected per day and downlinked via X-band with 320 Mbits/s in 31 minutes/day. The chosen Sun-synchronous orbit combined with a ±30° off-nadir pointing feature allows each point on Earth to be revisited within 4 days. For more information see the EnMAP-KML
Platform and Launcher
The instrument is accommodated on top of the platform accounting for the demanding stability and thermal requirements of the high-resolution optical remote sensing system. The platform comprises highly accurate attitude control and a high rate data processing chain. The satellite dimensions are compatible with the fairing of the Falcon 9 launcher by Space X, which is able to lift the satellite into the required orbit.