SP-168 EXPLORING SPACE WITH A CAMERA

An overlapping Mercator mapping of regions bracketing the areas

"One hundred and fifty vidicon camera images collected by the ESSA III satellite were combined in the pictures on this page to reveal the cloud cover over the entire Earth on January 6, 1967," CHARLES L. BRISTOR, Chief, Data Processing and Analysis Division, at the National Environmental Satellite Center, tells us. "Each (800 scan line) image signal has been converted into 640 000 separate digital brightness samples. The fastest computer presently available is used to partially correct each image for variations in solar illumination and camera-lens vignetting. The pictures are cropped to reduce overlap and then mapped in full resolution on northern and southern hemispheric polar stereographic projections (shown above). An overlapping Mercator mapping of regions bracketing the areas is below.

"Such routine mapping is creating montage images for timely use in weather briefing for pilots flying transoceanic routes and for use in improving weather analyses and forecasts. It also is providing vital input for further computer efforts toward the automatic extraction of information."


- Back -