There is a need, in remote sensing, to calibrate and independently validate the instruments onboard the satellites. Quality in-situ data is required to assess instrument performance, and to determine what adjustments may be required.

Validation is the process of matching in situ datapoints with spatially and temporally coincident satellite measurements. The more reliable data available the better, and the ideal situation is to have a large, standardised database of in situ measurements from all over the world, that can be used to validate ocean colour measurements from the ESA MERIS instrument onboard Envisat.

The task of ARGANS is to collate in-situ data from research institutes all over the world, and to build and maintain a database of coincident in-situ data with their counterpart MERIS product. ACRI-ST will use the database for validation, and ARGANS will work closely with ACRI-ST to decide upon the algorithms and techniques for carrying out such validation.

Another part of ARGANS role is to keep the reference model documents that support this work up to date, and to aid in algorithm improvements where necessary.