SPOT HRVIR: A significant improvement of high resolution visible SPOT camera to i.r. wavelengths☆

Abstract Since March 1986, the SPOT-HRV cameras are imaging the Earth in a 10 m resolution panchromatic mode and three 20 m resolution spectral modes all in the visible and near infra-red wavelengths. The interest of medium i.r. imaging for observing vegetation has raised in the past and the implementation of a 1.6 μm band was decided by CNES for SPOT 4. New 3000 elements detector matrix had to be developed. This work is nearly completed now through a contract placed at Thomson by CNES. In parallel, the focal plane of the previous HRV cameras has been completely redesigned and the video electronics has also been significantly improved taking into account both some problems identified on SPOT 1 in orbit and the implementation of the MIR band. A significant change in integration and test is introduced by the operating temperature of the MIR detectors to be accurately controlled at 5°C and a calibration of the whole instrument in vacuum is foreseen. Following a presentation of HRV-SPOT 1 main flight results, technical and programmatical points of the SPOT 4 HRVIR situation is presented in the paper.