EnMAP – An Advanced Optical Payload for Earth Observation

The potential of imaging spectroscopy to provide more and better information about the Earth system than traditional multispectral instruments is currently not counterbalanced by an equivalent availability of space-borne spectroscopy data. The Environmental Mapping and Analysis Program (EnMAP), a German hyperspectral mission scheduled for launch in 2013, is intended to cover this gap. The primary goal of EnMAP is to offer accurate, diagnostic information on the state and evolution of terrestrial ecosystems on a timely and frequent basis, and to allow for a detailed analysis of surface parameters with regard to the characterisation of vegetation canopies, rock/soil targets and coastal waters on a global scale. EnMAP is designed to record bio-physical, bio-chemical and geo-chemical variables to increase our understanding of biospheric/geospheric processes and to ensure the sustainability of our resources. EnMAP will sample areas of 30 x 30 km with a ground sampling distance (GSD) of 30 m, measuring in the 420-2450 nm range by means of two separate spectrometers covering the visible to near-infrared (VNIR) and short-wave infrared (SWIR) spectral regions. The mean spectral sampling distance and resolution is of 6.5 nm at the VNIR, and of 10 nm at the SWIR. Accurate radiometric and spectral responses are guaranteed by a required signal-to-noise ratio (SNR) of about 500:1 in the VNIR and about 150:1 in the SWIR, a radiometric calibration accuracy better than 5% and a spectral calibration uncertainty of 0.5 in the VNIR and 1 nm in the SWIR. An off-nadir pointing capability of up to 30° enables a target revisit time of 4 days. Recent scientific activities have been focused on the development of a forward scene simulator to support hardware developments and the consolidation of the mission concept.