(11 February 2013) The French Spot satellites have been charting the world’s vegetation since 1998.
This important task soon falls to ESA’s Proba-V, which, despite being only a little larger than a washing machine, will provide sharp views of Earth’s plant life every two days.
Keeping a close check on the health of vegetation is not only essential for monitoring environmental change, but also for numerous practical applications – importantly, those related to agriculture and food security.
Over the past 10 years, more than 8000 registered users around the world have relied on data from the Vegetation instruments on Spot-4 and Spot-5.
Since the sensor on Spot-4 stopped supplying data last year and Spot-5 is expected to come to an end in the middle of 2014, the upcoming Proba-V mission has been designed to continue the supply of this much-needed imagery.
Furthermore, after the loss of Envisat and its MERIS camera, Proba-V will help to bridge the gap until the launch of the Sentinel-3 mission, which carries the Ocean Land Colour Instrument to follow on the 10-year time series of MERIS data.
Proba-V will fly a reduced-mass version of the Vegetation instrument currently on board the Spot satellites to provide a daily overview of global vegetation growth. The Proba satellites are part of ESA’s In‑orbit Technology Demonstration Programme: missions dedicated to flying innovative technologies. (courtesy: ESA-P.Carril)
The V in Proba-V also stands for Vegetation, but the design is somewhat different to Spot’s – it is much smaller. The whole satellite is less than one cubic metre, with the sensor being a cleverly miniaturised version of Spot-5’s full-size camera.
The old saying ‘good things come in small packages’ is certainly apt for Proba-V. This small satellite carries a very wide-angle telescope with a 2250 km field of view, about double the width that MERIS offered. It will also deliver a spatial resolution three times sharper than the Spot Vegetation sensor.
This width of view means that Proba-V will provide global coverage every two days, with latitudes 35–75°N and 35–56°S covered daily. It operates in four spectral bands: blue, red, near-infrared and mid-infrared, which are ideal for environmental and agricultural monitoring.
Thanks to its range of spectral bands, Proba-V can distinguish between different types of land cover and plant species, including crops. It will provide a clear picture of the plants so their health can be easily monitored. This microsatellite is therefore especially relevant for improving agricultural practices, tracking desertification and vegetation burn scars.