surface temperature, and salinity. Data and results of experiments 

 are to be exchanged with a view to assessing utility of employing 

 remote sensing to investigate the Bering Sea region. (Unfortunately 

 the aircraft and its crew were lost in a tragic accident in April 1973.) 



Satellite Platforms 



Requirements for the acquisition of marine environmental data on 

 a repetitive, synoptic, and long-term basis over regions of broad 

 extent or on a global scale can in large part be met by the use of 

 appropriately instrumented earth-orbiting spacecraft or satellites. 

 Such satellites can and do play three roles: platforms for marine- 

 environment remote sensors; data-relay links for the transmission of 

 data collected by instrumented buoys, ships, and off-shore 

 platforms to a central data processing facility; and elements of 

 ocean-platform position-location systems. 



To date, no satellite mission has been dedicated to oceanographic 

 data acquisition. However, satellites such as Nimbus and ITOS (for 

 Improved TIROS Operational Satellite), and manned Gemini and 

 Apollo earth-orbiting spacecraft, did carry sensors which obtained 

 information on sea-ice distributions, coastal phenomena, and sea- 

 surface temperature. In view of the progress made in high-spatial- 

 resolution visible and infrared scanners, such sensors are being 

 integrated into the operational NOAA series of environmental 

 satellites. With the successful launching of the first Earth Resources 

 Technology Satellite (ERTS-1) by NASA in July 1972, a concerted 

 effort began to assess the feasibility and utility of employing multi- 

 spectral images in the visible spectrum for marine environmental 

 surveys. Such imagery has been found quite useful for 

 investigations of marine bioproductivity, the dispersal of sewage 

 sludge and acid waste product dumpings in offshore waters, 

 variations in sea-ice conditions, water quality, the transport of 

 sedimentation plumes, coastal zone processes, shallow-water 

 bathymetry, and estuarine dynamics, and for mapping and 

 delineating the depths of shallow-water bottom features such as 

 shoals and bars. 



The NOAA-2 Satellite, built by NASA for NOAA, and known as 

 ITOS-D until it became operational in October 1972, is acquiring 

 thermal data of great interest to oceanographers. This satellite 

 carries a scanning radiometer and a very-high-resolution radiometer 

 which have thermal channels that detect sea-surface temperature 

 variations in cloud-free areas. Thermal imagery having a one-half 

 nautical mile resolution is being obtained. Such data are being used 

 by the Inter-American Tropical Tuna Commission for correlations to 

 the tuna fisheries. The NOAA-2 thermal imagery is also providing 

 improved sea-ice distribution data on a 24-hour basis in cloud-free 

 areas. 



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