Compact Optical Payload for Daily Survey of Vegetation from Small Satellites

Recent advancement of optics fabrication, metrology and detectors are the basis for the development of a new compact instrument designed to provide daily revisit for the analysis of vegetation. The instrument has been optimized to improve multispectral imaging capabilities with respect to Spot-Vegetation, while minimizing mass and power to be accommodated on a small satellite. The new technologies used for this instrument allow shrinking the mass and reducing the power consumption of a factor 5 with respect to Spot-Vegetation. The new instrument is designed to fly on Proba-V, a small satellite developed to ensure continuation of the Spot-Vegetation products. The paper gives an overview of the payload, presents its performance and explains which innovations allow a very compact design. In particular, the paper presents the technology used for the fabrication of mirrors, the approach used for their alignment, and the tests results obtained so far on the first prototype of the telescope. A section of the paper describes the InGaAs detector developed for the SWIR channel, a long linear array able to operate uncooled. The paper concludes with a description of the mission, of the payload accommodation on the small satellite, and of the data produced.