This paper describes the routine generation of ASAR mosaics at ESRIN and their distribution via Web map servers. ASAR products are automatically collected from various processing sites to be geocoded and mosaicked on the GRID Processing on Demand system at ESRIN. New mosaics are automatically transferred to an OpenGIS Web map server where they can be directly visualized at full resolution by external users. The generation of mosaics involves several processing steps including antenna pattern correction and compensation of incidence angle depending on vegetation type. Several map projections are supported including polar stereographic projections (Arctic and Antarctic's) as well as Plate Carre acutee projections (entire World).