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(b) -The ISTP program is the largest concept in the 



geophysics discipline and the one most generally 

 international in cost sharing and scientific 

 cooperation. Individual satellites would be built 

 by NASA, ESA, the Japanese Space Agency and the 

 USSR, but all would be placed in complementary 

 orbits and designed to provide unified sets of 

 data. ISTP has been jointly planned in great 

 detail. It remains for the various nations to 

 meet their commitments in the same time frame so 

 that the coordinated observations can be achieved. 

 - Observations of the oceans require several 



missions to provide the variety of sensors and 

 geographical perspectives essential to global 

 models. The 0. S. is moving ahead on TOPEX, which 

 will observe circulation in the great ocean basins 

 but primarily in mid-latitudes. NROSS will 

 complement TOPEX from a higher inclination orbit, 

 giving more coverage of arctic oceans. The 

 European Earth Resource Satellite (ERS) mission, a 

 Canadian SAR mission and a Japanese SAR are in the 

 future picture. If all these missions are 

 coordinated for international cooperation, the 

 total returns will be much greater than the sum of 

 the individual missions done in isolation. 



