Automatic Picture Transmission (called APT) that was flown on Nimbus I reduced the time required and the cost of getting photographic information from a satellite to local weather forecasters. The four pictures at the right were received at Wallops Island, Va.
F. W. REICHELDERFER, former Chief of the U.S. Weather Bureau, wrote of them: "In this four-frame sequence, Nimbus I reveals many things about the weather in a 900-mile swath from Venezuela to the Canadian Arctic as viewed on August 29, 1964, from orbit approximately 550 statute miles from Earth. Through APT, the local or regional weather forecaster receives pictures of the cloud arrays as the satellite passes overhead. APT receivers are fairly simple and inexpensive.
"The two top pictures show clouds typical of systems of fronts. In mid-latitudes and the subarctic, warm fronts produce cloud 'decks' of cirrostratus and altostratus. Cold fronts produce convective cumulus and line-squall cumulonimbus. Intermediate frontal forms give the complex combinations of cloud forms and arrays seen in the pictures-their orientations and shapes being indicative of different wind currents, etc.
"The third picture looks down upon historic Hurricane Cleo over South Carolina and Georgia. The characteristic spiral bands of clouds first seen in full by rocket and satellite photos make it easy for satellites to discover tropical cyclones far at sea outside the usual networks of ship reports.
"In the fourth picture the many cumulus 'streets' often found in the trade winds can be seen; also southward are the cloud masses of an intertropical convergence zone.
"Perhaps most promising for future weather analysis and forecasting is the increasing study of clouds and their arrays as symptoms' and thus diagnostic means for identifying atmospheric dynamic systems which make the weather."