On Board Images & Data
The current trends in the EO market show a clear increase in the amount of information to be acquired by the different sensors of the satellites. In many cases this is multiplied by the fact that future systems are taking the form of small and medium platform constellations. This is a critical combination as the size of images increases, the number of sensors increase and the size of platforms, and therefore the power and budget links available for downloading the images, decrease.
All the previous means that it is appearing a strong need to pre-select on board the images to be stored and or downloaded and, in the same way, it is necessary to adapt dynamically the different video compressing algorithms depending on the relevance, complexity and criticality of the images to be compressed. In addition to a new high performance & high resolution CMOS image sensor, the VIDEO instrument will demonstrate adaptation to these new market needs as it will include a dynamically reconfigurable video processor that will be able to adapt its behavior both to the nature of the images to be acquired and to the environment of the satellite. The adaptive video processor shall be able to take autonomously the following actions:
- Adapt the video compression ratio depending on the satellite available resources: Mass memory available, power available for the data processing.
- Adapt the video compression ratio to the available downlink bitrates for those images downloaded in real time.
- Detect certain image features such as cloud or ocean covered areas and apply selectively higher compression ratios to those “low interest” areas
- Select between lossy and lossless compression algorithms depending on the previously mentioned parameters and on the commanded target image quality
- Select and filter out non-useful images due to cloud cover, haze and other deleterious phenomena.
- Open the way for further sensor evolutions to hyperspectral imaging and even higher resolutions (>100Mpixels).