The visible, near-infrared and short wave infrared channels of the EarthCARE multi-spectral imager

Doornink, J.; de Goeij, B.T.G.; Marinescu, O.; Meijer, E.; Vink, H.J.P.; van Werkhoven, W.P.; van 't Hof, C.A.; TNO Industrie en Techniek

doi:10.1117/12.2309153

The visible, near-infrared and short wave infrared channels of the EarthCARE multi-spectral imager

Title

The visible, near-infrared and short wave infrared channels of the EarthCARE multi-spectral imager

Author

Doornink, J.
de Goeij, B.T.G.
Marinescu, O.
Meijer, E.
Vink, H.J.P.
van Werkhoven, W.P.
van 't Hof, C.A.
TNO Industrie en Techniek

Contributor

Armandillo, E. (editor)
Cugny, B. (editor)
Karafolas, N. (editor)

Publication year

2010

Abstract

The EarthCARE satellite mission objective is the observation of clouds and aerosols from low Earth orbit. The payload will include active remote sensing instruments being the W-band Cloud Profiling Radar (CPR) and the ATLID LIDAR. These are supported by the passive instruments Broadband Radiometer (BBR) and the Multispectral Imager (MSI) providing the radiometric and spatial context of the ground scene being probed. The MSI will form Earth images over a swath width of 150 km; it will image the Earth atmosphere in 7 spectral bands. The MSI instrument consists of two parts: the Visible, Near infrared and Short wave infrared (VNS) unit, and the Thermal InfraRed (TIR) unit. Subject of this paper is the VNS unit. In the VNS optical unit, the ground scene is imaged in four spectral bands onto four linear detectors via separate optical channels. Driving requirements for the VNS instrument performance are the spectral sensitivity including out-of-band rejection, the MTF, co-registration and the inter-channel radiometric accuracy. The radiometric accuracy performance of the VNS is supported by in-orbit calibration, in which direct solar radiation is fed into the instrument via a set of quasi volume diffusers. The compact optical concept with challenging stability requirements together with the strict thermal constraints have led to a sophisticated opto-mechanical design. This paper, being the second of a sequence of two on the Multispectral Imager describes the VNS instrument concept chosen to fulfil the performance requirements within the resource and accommodation constraints.

Subject

Space & Scientific Instrumentation
Industrial Innovation
Earth atmosphere
Infrared devices
Infrared radiation
Optical radar
Radiometry
Remote sensing
Solar radiation
Spectroscopy
Cloud profiling radar
Direct solar radiation
In-orbit calibrations
Instrument performance
Opto-mechanical design
Performance requirements
Remote sensing instruments
Stability requirements