Figure 23. £'55'^ 6 satellite photograph of 

 ice and cumulus clouds, Labrador Sea, March 

 18, 1968. Note solid ice cover over Greenland 

 (top center). (ESSA photo) 



BUS). The International Ice Patrol regularly uses 

 satellite ice data to augment information acquired 

 by ships and aircraft. The U.S. Army Cold Regions 

 Research and Engineering Laboratory, the Uni- 

 versity of Michigan, and the Naval Oceanographic 

 Office are conducting research in the use of 

 infrared radiometry for sea ice surveys. 



These techniques suffer from an inability to see 

 through clouds that are common in the polar and 

 sub-polar areas where ice is present, as well as the 

 limited daylight hours over a portion of the year. 

 As a result, recent studies have turned to the 

 development of other techniques; sidelooking 

 radar and passive microwave imagery. The Coast 

 Guard is investigating the use of microwave 

 imagery for iceberg and sea ice surveys. NASA has 

 reported considerable success in airborne tests of 

 this technique;'" it may be possible to obtain 

 useful ice-thickness measurements, as well as other 

 related data. 



Spectral analysis techniques have been sug- 

 gested for mapping chlorophyll on the ocean 

 surface for use in forecasting fish abundance. 



'"Catue, C. W. Nordberg, P. Thaddeus, & G. Long. 

 1967: Preliminary Results from Aircraft Flight Tests of 

 an Electrically Scanning Microwave Radiometer, Goddard 

 Space Flight Center, Greenbelt, Maryland, (X-622-6 7-352) 

 35 pp. 



C. Satellites— Communications 



The United States has several programs de- 

 signed 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 program 

 is OPLE (Omega Position Locating Equipment), a 

 prototype of which has flown on the synchronous 

 ATS-3 (Apphcation Technology Satellite). 



OPLE is capable of interrogating thousands of 

 separate surface units deployed at random, ac- 

 curately fixing their positions, and recording their 

 data twice daily. This system would provide a 

 means of obtaining data from instrumented buoys 

 as well as sensors on other platforms. Another 

 related program is IRLS (Interrogation, Recording 

 and Location System), planned for flight testing 

 aboard a future polar-orbiting NIMBUS satellite. 

 These techniques must be compared for cost and 

 effectiveness with other, rhore conventional ap- 

 proaches; such comparisons are in progress. 



Recommendation : 



The development of satellite-bome oceanographic 

 sensors as well as techniques for the location of, 

 and transmission of data from, other platforms 

 now in progress at NASA should continue. Plans 

 for early use of oceanographic sensors on board 

 operational satellites should be piu^ued vigorously. 



IV. APPRAISAL 



Many technical developments are at a stage 

 where they can provide a significant improvement 

 in observing the environment, transmitting and 

 processing the observed data, and retransmitting 

 forecasts. Progress has been noted in the develop- 

 ment of new data-collection platforms: satellites 

 and buoys. Developments for remote sensing of 

 the environment from satellites, as well as aircraft, 

 show great potential. New data-processing capabili- 

 ties, under development primarily for other 

 reasons, also promise an improved capability to 

 process incoming data and provide accelerated 

 forecasting capabihties. Progress in data processing 

 and communications offers the promise of being 

 able to transmit vast quantities of data rapidly and 

 economically. 



11-45 



