193 



craft. Several ag:encies are proceeding with 

 studies of the use of aircraft for collecting 

 oc«anographic data. It appears desirable to 

 examine the feasibility of an aircraft-of- 

 opportunity program as part of an overall 

 obser\at ional system. 



The Commission recommends that the 

 role of aircraft in collecting oceanographic 

 data be reviewed with the aim of estab- 

 lishing an aircraft-of-opportunity pro- 

 gram. 



Satellites 



Among the most dramatic recent develop- 

 ments is the ability to collect useful ocean 

 data from remote platforms in space. Earth 

 orbiting satellites long liave demonstrated an 

 operational capability to provide global 

 weather photographs; they now have dem- 

 onstrated a capability to collect and trans- 

 mit oceanographic data and act as a data 

 communications relay. 



The TIROS, NIMBUS, and ESSA series 

 of satellites have demonstrated amply the 

 operational capability to provide useful 

 global photographs showing clouds and lim- 

 ited indications of sea ice ; other applications 

 are under development. The Application 

 Technology Satellite series in earth-syn- 

 chronous orbits has shown the ability to keep 

 major parts of the atmosphere and ocean un- 

 der constant surveillance. 



Progress is being made in development of 

 advanced satellite instrumentation. Sea sur- 

 face temperature discontinuities have been 

 detected from aircraft using sensors in the 

 visible, infrared, and microwave regions of 

 the spectrum. Infrared instruments have been 

 used to map and measure areas of strong 

 thermal contrast. Under nighttime, cloud- 

 free conditions, such areas of sharp tempera- 



ture contrast as currents and upwellings have 

 been detected by NIMBUS imagery. 



Most sea state infonnation is inferred 

 f roin wind data. Possible methods for deter- 

 mining sea state from orbital altitudes are 

 based on changes in the reflective properties 

 of the ocean surface. Photographs of sun 

 glitter or sun glint have been made from air- 

 craft and satellites. The cloud cover con- 

 straints on optical techniques have stimulated 

 study of passive microwave radiation and 

 radar reflectance for determining sea state. 

 Both of these measurements can be made in 

 the presence of storms and clouds with no 

 appreciable attenuation. 



Several developments are underway to 

 demonstrate the feasibility of using satellites 

 to locate, interrogate, and relay data from 

 meteorological and oceanographic buoys, 

 stream gauges, drifting balloons, ice islands, 

 and other environmental data platforms. 

 One of these programs is Omega Position 

 Locating Equipment (OPLE), a prototype 

 of which has flown on the synchronous satel- 

 lite, ATS-3. This equipment is capable of in- 

 terrogating thousands of separate surface 

 units deployed at random, of accurately fix- 

 ing their position, and of recording their 

 data twice daily. This system would provide 

 a means of obtaining data from instrumented 

 buoys. Another related program is the Inter- 

 rogation, Recording, and Location System 

 (IRLS), planned for flight testing aboard 

 a future polar-orbiting NIMBUS satellite. 

 Other approaches to satellite interrogation 

 of free-floating platforms are being exam- 

 ined by France. 



A distinction must be maintained between 

 the responsibilities of the National Aeronau- 

 tics and Space Administration for research 

 and development of new satellite systems and 

 of user agencies for the finiding and man- 

 agement of operational satellite systems. 

 Such arrangements have worked effectively 



