study. Now one can obtain time lapse synoptic imagery of sea surface temperature and 

 turbidity or color. Velocity might be derived from measurements of the displacement of 

 identifiable parcels of water. Sea surface salinity can not be determined remotely at the 

 present, but if salinities are associated with specific temperatures or turbidities they can 

 be mapped and tracked in a given region. 



II. THE SYSTEM 



The U.S. Air Force System presently includes a classified space segment and several 

 earth based segments. Data Acquisition and Processing Program (DAPP) is the Air Force 

 land based segment consisting of a central acquisition and processing site and a number of 

 air-tronsportable land-sites. The present Navy segment of this system will consist of two 

 shipboard and two air-transportable land-based terminals next summer/fall followed by a 

 new central data acquisition and processing site at Monterey next winter. As the Air Force 

 and Navy earth-based segments bear a number of similarities the Air Force DAPP will be 

 described. DAPP acquires, processes, displays and disseminates very high resolution re- 

 motely sensed data directly and on tape which is gathered from space. The Air Force as lead 

 agency has provided the following information and specifications necessary for data 

 utilization on an unclassified basis. 



The sensors of the present system are mounted on two sophisticated satellites in near-polar, 

 sun-synchronous orbits at 450 n.mi. altitudes. The nodes (equatorial crossings) are ascending 

 south to north on the daytime side of the earth and descending on the nightime side. The 

 orbital period is about 100 min. and the satellites step around the equator at 25°-longitude 

 increments each successive nodal crossing. The spaceborne segment of the system consists of 

 scanning infrared sensors operating in the spectral range of 8.0-13.0^ m and video (visual 

 range) sensors in the 0.4-1 . 1//. m range , The infrared sensors scan the earth and It atmosphere, 

 recording the total effective blackbody emittance reaching satellite at the 450 n.mi. distance 

 in space. The visual sensors receive brightness levels of reflected solar illumination to transmit 

 albedo of the earth within the spectral range sensed. Both visual and infrared data are avail- 

 able as photograph-like imagery at 2 or 1/3 nautical mile maximum resolution formats, in 

 near real-time. The field of view of the scanning sensors gives a swath width of 1560 n.mi. 

 for each pass. In addition to the picture-like imagery, an 8-channel radiometer, furnishes 

 the DAPP with vertical temperature profiles of the atmosphere. The sensors and spacecraft 

 are designed to be capable of functioning at any local sun time. The DAPP receives space- 

 craft data sensed near dawn near noon, early evening, and near midnight local sun time 

 anywhere around the globe. 



The DAPP satellite data are transmitted to earth via high speed (wide-band) data-links. 

 There are two kinds of receiving sites, permanent receiving sites in the United States that 

 relay data to the Air Force Global Weather Central, and mobile remote receiving sites for 

 direct local readout, transportable anywhere in the world. The mobile site equipments 

 including the tracking and receiving antenna, are contained in vans, for air or ship trans- 

 portability. The permanent receiving sites acquire tape recorded satellite data for the 

 entire globe encircling orbit, a 1560 n.mi. swath in a near polar orientation. The remote- 

 site receiver acquires only o direct readout of about a 3000 n.mi. segment of an orbit as 

 the satellite passes within line-of-sight. The Navy will add two shipboard readout mobile 



