ATS-III: Making the Images Available

Jean PhillipsSchwerdtfeger Library, Space Science and Engineering Center

University of Wisconsin-Madison

ASLI Conference, 12-13 January 2005, San Diego, CA

18 November 1967 Movie

Discussion Threads

• The Spin-Scan Camera Idea

• Spin-Scan Camera on ATS-I

• Spin-Scan Camera on ATS-III

• Database, ATS Image Classification

• Searching the Images

• Conclusion

The Spin-Scan Camera Idea

• Verner Suomi, Father of Satellite Meteorology

• Payload of ATS-I, 1966

• Payload of ATS-III, 1967

• Pioneered continuous viewing of weather from space

Camera Idea, cont.

• Suomi understood benefits of observing single weather events at frequent intervals

• These observations not possible with polar orbiting satellites

• NASA’s new geostationary satellite, Applications Technology Satellite (ATS)

Camera Idea, cont.

• “The weather moves, not the satellite” (Suomi)• Suomi used the spin of the satellite to scan the

earth – 2400 satellite revolutions needed to produce one Earth image

• The camera scanned a small strip of the Earth with each rotation, tilting slightly for the next rotation (or line of the picture)

• Image of Earth created in about 20 minutes

Camera Idea, cont.

• Spin-Scan Camera allowed scientists to observe weather systems as they developed

• A concept that revolutionized satellite meteorology

• Weather satellite images and “movies” of weather in motion were seen on the news as a result of Suomi’s invention

• The technology soon became operational – it was now possible to track air motion, cloud heights, rainfall, natural disasters and other weather events

Spin-Scan Cloud Camera on ATS-I

• Dr. Suomi was the PI for the ATS-I Spin-Scan Cloudcover Camera (SSCC) Experiment

• Launched on 7 December 1966 and among other things, was designed to collect and relay cloudcover pictures

• ATS-I spacecraft was a cylinder 54” long and 57.6” in diameter

• Experiment successful through 16 October 1972 (From: The Applications Technology Satellite Meteorological Data Catalog: Volume I)

ATS-I Spacecraft

From: The Applications Technology Satellite Meteorological Data Catalog: Volume I)

Spin-Scan Cloud Camera

From: The Applications Technology Satellite Meteorological Data Catalog: Volume I)

Multicolor Spin-Scan Cloudcover Camera (MSSCC) on ATS-III

• Multicolor Spin-Scan Cloudcover Camera (MSSCC) Experiment led by Dr. Verner Suomi

• Launched 5 November 1967• Provided color pictures for only three

months when red and blue channels failed• Continued to provide black-and-white

pictures until 11 December 1974

MSSCC, cont.

• Cylindrical spacecraft was 54” long and 57.6” in diameter

• Two solar arrays provided 175 watts for ten experiments in addition to the MSSCC Experiment (From: The Applications Technology Satellite Meteorological Data Catalog: Volume II)

ATS-III Spacecraft

From: The Applications Technology Satellite Meteorological Data Catalog: Volume II

Multicolor Spin-Scan Camera

From: The Applications Technology Satellite Meteorological Data Catalog: Volume II

BAMS Cover, February 1968ATS-III, 10 November 1967

ATS-I & -III Montage, 10 November 1967BAMS, February 1968

MSSCC, cont.

• Purpose of adding color was to help estimate the altitudes of cloud tops

• The red/blue channel ratio along with zenith angle is used to calculate cloud altitude

• Color gives better contrast between clouds and background

• ATS-III camera capable of full disk Earth images which is aesthetically more pleasing

• ATS-III provided first useful color photography from this altitude (From: BAMS, v.49, no.2, February 1968, pp74-83)

ATS Image Classification

• Images include metadata gathered from the ATS Data Catalogs

• Each image can be viewed at high or low resolution

• Records include: thumbnail, date and time notations, geographic location, print quality designation, satellite designation

Images, cont.

• Source documents scanned “as is” so that digital image represents hard copy original

• Images color-corrected

• Record includes link to uncorrected original

Uncorrected Image18 November 1967, 153255Z

Color-corrected Image18 November 1967, 153255Z

Searching the Images

Searching, cont.

• Search parameters: date and time range, image quality, and geographic locations

• http://library.ssec.wisc.edu/spinscan

Why Bother?

• First true color images from a geostationary satellite, capturing frequent weather observations over large fraction of Earth’s surface

• After it became operational, the technology improved the accuracy of forecasting

• Adopted for many satellites built for NASA, NOAA, ESA, Japanese Meteorological Agency, Chinese National Satellite Meteorological Center

• Physical collection is degrading, needs preservation, and is difficult to use

• Electronic files no longer available• Extends available climate data set to pre-SMS,

allowing scientists to study weather history over a longer baseline

• Legacy of Dr. Verner E. Suomi