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GRAS SAF

Assisted Raw Sampling

NEW: The reports on 'Assisted Raw Sampling Mode' and 'Assisted Raw Sampling Report' are now available.

During the GRAS SAF GOLW workshop that took place 6-8 June 2005, in Helsingør, Denmark, it was made evident that to obtain the full benefit of the GRAS instrument it was needed to find a mechanism to extract the navigation bit from the phases produced by the GRAS instrument in the high sampling rate mode. It was subsequently decided to investigate this topic within the GRAS SAF Visiting Scientist Program and initiate the 'Assisted Raw Sampling (ARS) project. This project is carried out by Oleguer Nogues at IEEC in Barcelona.

The points to be investigated with the ARS project are:

• - to extract the Navigation Bits (NB) from the GPS signals using simple and reliable equipment
• - to propose means to transfer the NBs to a GRAS SAF server
• - to define algorithms to correct, in post processing, the GRAS observed phase when sampling rates are 50 Hz or higher
• - to produce, and to test, a prototype implementing the required functionalities to deliver to the GRAS SAF servers navigation bit streams

While this activity is within the GRAS SAF responsibility, we expect that the results could be implemented in the future within the EUMETSAT GRAS processing chain.

Details on the work done and the present status of ARS can be found here: https://bond.ieec.uab.es/ars/index.php