ESA comes up with a highly detailed camera that can be used for precision agriculture. The camera can observe details of around 4 to 5 centimetres.
Hyperspectral
ESA's cameras, which are also used aboard satellites, are called hyperspectral. Hyperspectral imaging collects and processes information across a wide range of wavelengths of the electromagnetic spectrum (which includes the 'visible' light we can see with our eyes). By studying the 'fingerprints' left by certain objects in the electromagnetic spectrum, one can study their properties.
Currently, the camera is being used for biodiversity research in Denmark and in Australia and Italy it is being used to provide farmers with commercial data. The makers will use this data to market a proper commercial version of the camera.
Multiple applications
Belgian companies imec and VITO Remote Sensing, among others, played a major part in developing the camera. Imec supplied a new hyperspectral chip and the latter the image processing capacity. VITO already had experience with ESA's Earth observation satellites.
The camera weighs barely 400 grams but is very powerful, and its low weight means it fits well on small unmanned aerial vehicles and can take detailed measurements. The camera can be used for precision agriculture but also for forestry, waste and pollution tracking and biomass monitoring.
"In hyperspectral imaging, very many narrow frequency bands - say colours - are observed in visible and near-infrared wavelengths instead of the more typical red, green, blue and sometimes infrared frequency bands," says Bavo Delauré of VITO Remote Sensing in a press release. "By viewing the world in more colours, certain phenomena can be observed faster and more accurately. A camera that is more sensitive to subtle hues allows one to identify problems that one cannot see with the naked eye or a normal camera until it is too late to do anything about them."
The HyperScout hyperspectral camera
Colours can also be analysed using prisms, but the cameras that use this are quite large because of the complex optics. ESA asked VITO to build a hyperspectral lightweight camera based on a different technology.
A variable filter placed in front of the detector was used for this purpose. This not only makes the instrument as compact as a standard colour camera but also makes it suitable for use in small satellites and drones.
Dutch Cosine Research, which develops measurement systems, will use such an instrument with their HyperScout camera for the small nanosatellite GomX-4B. That will go into space later this year.
By: Kelly Bakker
Source: ESA/Cubert
