Data Processing Systems

Defining product contents, implementing processing algorithms and generating the end products. From plan-driven approaches to data-driven approaches.


Payload Data processing activities first require a deep analysis into the Mission and Instrument objectives. The goals range from the definition of the interfaces and Product contents, to the analysis and implementation of processing algorithms suitable to the Instrument(s), and their integration into the Ground Segment infrastructure.

smosDuring the design of Data Processing facilities, a careful study must be performed on the scientific community needs for data coming from the Instrument(s), and also on the available processing algorithms. Prototyping activities may be initiated in case sufficient knowledge is not available, or new ideas are being worked out. Outputs from this initial stage are the Auxiliary data needs, Mission Products formatting and contents and Algorithms Baselines.

Regarding processing strategies, there are two main currents nowadays: plan-driven and data-driven. Plan-driven processing (e.g. ENVISAT PDS) relies on a-priori information on the Instrument(s) configuration and data downlinks to establish an optimised processing plan. The processing algorithms are selected according to this plan and the output is expected to follow the plan as well. Data-driven processing does not rely on any knowledge; in turn, it analyses all the input data it finds, in order to try to determine the best processing algorithm.

As it can be seen, plan-driven processing allows for better optimisation of the Ground Segment resources, but in turn is less flexible to exceptions that may appear when the data received is different from the expected plan. On the other hand, data-driven approaches are completely flexible, they depend on the level of autonomy built in their knowledge database, but may have difficulties in the optimisation of GS resources under certain circumstances.

DEIMOS is currently working in several projects involving data processing, covering all the different steps into the design and final implementation of Data Processors. Examples include the design and implementation of the SMOS L1 Processor Prototype, and several processors for the Sentinel-3 mission.
 

SMOS

The SMOS (Soil Moisture & Ocean Salinity) mission is an ESA satellite that has been designed...
See more