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About the ATS Image Collection




The Spin-Scan Camera Idea

In the mid-1960s, Dr. Verner E. Suomi, founder of the Space Science and Engineering Center, University of Wisconsin-Madison and “Father of Satellite Meteorology,” invented the Spin-Scan Camera. This instrument was the payload of the Applications Technology Satellites –I and –III (ATS-I and ATS-III) launched in 1966 and 1967, respectively. The launching of the ATS-I into geosynchronous Earth orbit pioneered continuous viewing of weather from space. The ability to obtain continuous satellite imagery of a fixed point on the earth, at 20-minute intervals, allowed scientists to study a synoptic picture of existing meteorological conditions for the first time. Having this period in our weather history (1966-1972) accessible increases the time base available for climate study and modeling.

Before the age of remote sensing, Suomi understood the benefits that could be gained by observing a single weather phenomenon at frequent intervals. But these kinds of observations weren't possible using the early, low polar-orbiting satellites. NASA's new geostationary Advanced Technology Satellite (ATS), 22,000 miles out in space, would move in an orbit above the equator at the same speed as the Earth rotates on its axis. This is called geostationary orbit. For Suomi, the spin-scan idea was suddenly simple: "the weather moves, not the satellite." Suomi used the spin of the satellite to scan the earth -- 2400 revolutions of the satellite (spinning at about two revolutions per second) were needed to produce one complete image of Earth. Mounted aboard the spin-stabilized satellite, the camera scanned a small strip of the Earth with each rotation. By tilting the camera slightly for the next rotation (the next line of the picture), an image of Earth could be created in about 20 minutes. Suomi saw his Spin-Scan Camera launched on the ATS-1 in 1966.

The camera allowed scientists to observe weather systems as they developed. Satellite sensing technology was suddenly transformed from the production of interesting snapshots into the gathering of meaningful, quantitative data. This concept revolutionized satellite meteorology. The weather satellite images and "movies" of weather in motion seen on the evening news are a direct result of Suomi's invention.

Using these images, it was possible to measure and track air motion, cloud heights, rainfall, even pollution and natural disasters. This technology soon became operational. It helped to improve the accuracy of forecasting, improved models and has saved many thousands of lives over the years. While the original spin-scan design is no longer in use in the United States, Suomi's basic concept has been adopted for many satellites and space probes built for NASA, the National Oceanic and Atmospheric Administration, as well as the European Space Agency, the Japanese Meteorological Agency and the Chinese National Satellite Meteorological Center.

By 1967 the spin-scan pictures were in color -- the ATS-III was the only geostationary satellite with a blue channel which was, and still is, a unique feature. By 1971 work had begun on an instrument that would profile the atmosphere's temperature and water vapor from geostationary satellites. The Visible-Infrared Spin-Scan Radiometric Atmospheric Sounder (VAS) was a modification of the original spin-scan design with additional detectors for the various spectral bands. By observing temperature and moisture structures, Suomi hoped to improve the prediction of severe weather with increased understanding of how the atmosphere works.

When the VAS was launched in 1980 aboard the GOES-4 satellite, it performed with the accuracy Suomi had predicted in his original 1971 proposal. Suomi's work established the need for sounders and demonstrated their feasibility; profoundly affecting the field of atmospheric science.

With the advent of these new instruments, the flow of meteorological data quickly became an overwhelming flood. Experiments conducted under the Global Atmospheric Research Program (GARP) added to the already vast amount of data. To make sense of all this, or as he put it, to try "to get a sip from a fire hydrant," Suomi became the driving force behind the development of a computer system that could gather and handle the vast amount of imagery and data.

The study of the atmosphere and its dynamics quickly moved into the electronic age but the ATS photographs, until now, have not been part of this electronic data set. The ATS digitization project was undertaken to preserve the hard copy originals and make available a digital version of this unique, historically significant data set.

Exerpted from: Verner E. Suomi, 1916-1995: A man for all seasons. Madison, WI, Space Science and Engineering Center, (1996).

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Spin-Scan Camera on ATS-I and ATS-III

The Applications Technology Satellite-I was the first of a series of ATS scientific satellites built for NASA. Dr. Vernor Suomi of the University of Wisconsin-Madison, Space Science and Engineering Center, was the Principal Investigator for the ATS-I Spin-Scan Cloudcover Camera (SSCC) Experiment. The ATS-I was launched 7 December 1966 and was designed for the purpose of (1) testing new concepts in spacecraft design, propulsion, and stabilization, (2) collecting high-quality cloudcover pictures and relaying processed meteorological data via an earth-synchronous satellite, (3) providing in situ measurements of the aerospace environment, and (4) testing improved communication systems. (NSSDC). The basic ATS-I spacecraft was a cylinder 54 inches long and 57.6 inches in diameter with a solar cell array mounted around its periphery. The satellite weighed 775 pounds in orbit. (From: The Applications Technology Satellite Meteorological Data Catalog: Volume I)

The ATS-III was the third in this series of scientific satellites built for NASA. The Multicolor Spin-Scan Cloudcover Camera (MSSCC) experiment, one of eleven payloads of ATS-III was again led by Dr. Verner Suomi. The satellite was launched on 5 November 1967 and provided color pictures for approximately three months at which time the red and blue channels failed. The system continued to provide black-and-white pictures until 11 December 1974. (NSSDC). The basic ATS-III spacecraft was a cylinder 54 inches long and 57.6 inches in diameter. Two solar arrays containing 24230 silicon solar cells provided 175 watts for the 11 experiments and two 6 amp-hour nickel-cadmium batteries provided reserve power for transient loads and during periods of solar eclipse. (From: The Applications Technology Satellite Meteorological Data Catalog: Volume II)
The view of the earth from the ATS-III satellite at earth synchronous height is similar, in many respects, to that of the moon viewed from the earth. The earth goes through "phases" on a 24 hour cycle similar to the phases of the moon, with some differences (From: The Applications Technology Satellite Meteorological Data Catalog: Volume II)

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ATS Image Classification

All images in the ATS database include metadata gathered from the ATS Data Catalogs (Space Science and Engineering Center, University of Wisconsin-Madison). Each image can be viewed at high or low resolution and each record includes the following information:

Thumbnail: Thumbnail of the retrieved image.

Local Day: Date notation is in the form: month/day/year (e.g. May 28, 1968).

Greenwich Mean Date and Time: Date notation is in the form: 000/0 (e.g. 149/8) where 149 signifies the day of the year (149 of 365) and 8, the last digit of the year (1968). Time notation is in the form: 000000 (224834) where 22 is the hour of the day, 48 represents minutes and 34 represents seconds.

Location: Some, but not all, images are classified according to large geographic areas and include the following: Africa & Atlantic, Gulf of Mexico, Amazon River Area, Moon Shot, Azores Area, North Atlantic, Caribbean Area, Northern Hemisphere, Central America, Peru & Pacific, C. America & Pacific, South America, Earth Chip, United States, and Great Lakes Area.

Print Quality:

1. Many images are classified according to their quality: Good, 9/10 Good, 3/4 Good, 2/3 Good, 1/2 Good, 1/3 Good, 1/4 Good, 1/10 Good, and Poor. The quality of the image depends on the percentage of the earth visible, due to the sun's illumination, which is free from defects such as:
  • Part of the picture missing due to difficulties in satellite reception other than the polar areas (north of 50°N and south of 50°S), which are normally not visible because of the camera's limited field view.
  • Picture cut (part of picture missing) due to the tilt of the satellite's axis relative to the earth's axis. Note: the picture is considered cut if only one of the poles is visible.
  • Distortion, double exposures, synchronization failures.
  • Lack of contrast, poor focus, scratches, spots, etc.
  • Other specific descriptions may accompany the classification such as hemisphere, NH denotes northern hemisphere and SH, southern hemisphere, etc.

2. Good Whole Earth - image showing the earth fully illuminated by the sun, without defects. (Must be within 35 minutes of local noon, i.e. 2200 Greenwich Mean Time, to be considered a Good Whole Earth).

3. Most Complete (abbreviated "most com") - negative showing highest percentage of illuminated earth with fewest defects. Used only in the absence of a Good Whole Earth.

Sequence: All images are labeled in sequential order and may include a receiving station designation. The stations, Rosman, NC and Mojave, CA, are designated "R" and "M" respectively.

Satellite: Designates ATS-I or ATS-III.

Print: Black & White (B&W) or Color.

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ATS-III Movie: Weather in Motion and in Color (18 November 1967)

Weather in motion and color: From ATS-III synchronous satellite, by V.E. Suomi, A.F. Hasler, R.J. Parent, and J. Kornfield.  National Aeronautics and Space Administration (NASA) and Environmental Science Services Administration (ESSA), n.d.  10 minutes, color.  Schwerdtfeger Library Film #20.

The ATS-III movie is comprised of images from the first full day of good pictures taken from the Multicolor Spin-Scan Cloud Camera.

 

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Other ATS Documents and Resources (Search for additional ATS documents in the Schwerdtfeger Library Publications Database)

The Applications Technology Satellite Meteorological Data Catalog: Volume I, 1 January through 30 June 1967. Greenbelt, MD, National Aeronautics and Space Administration (NASA), Goddard Space Flight Center, October 1967. vii, 463p. Available in The Schwerdtfeger Library: QC 879.59 A1 A45 v.1 (reference, noncirculating). Describes the ATS-I system and offers an explanation of data acquisition, categorization, cataloging and archiving processes.

The Applications Technology Satellite Meteorological Data Catalog: Volume II
. Greenbelt, MD, National Aeronautics and Space Administration (NASA), Goddard Space Flight Center, n.d. vii, 353p. Available in The Schwerdtfeger Library: QC 879.59 A1 A45 v.2 (reference, noncirculating). Describes the meteorological experiments of the ATS-III system; the Multicolor Spin Scan Cloud Camera, and the Image Dissector Camera System.

The Applications Technology Satellites Meteorological Data Catalog: Volume III, 1 February through 31 December 1968. Greenbelt, MD, National Aeronautics and Space Administration (NASA), Goddard Space Flight Center, March 1969. vii, various paging. Available in The Schwerdtfeger Library: QC 879.59 A1 A45 v.3 (reference, noncirculating). Part I documents data from ATS-I, stationed over or near 151 degrees; Part II documents data from ATS-III, stationed at a number of positions between 95.1 degrees W longitude and 44.5 degrees W longitude.

The Applications Technology Satellites Meteorological Data Catalog: Volume IV
, 1 January through 31 July 1969. Greenbelt, MD, National Aeronautics and Space Administration (NASA), Goddard Space Flight Center, December 1969. v, various paging. Available in The Schwerdtfeger Library: QC 879.59 A1 A45 v.4 (reference, noncirculating). Part I documents data from ATS-I, stationed near 150 degress W longitude; Part II presents data from ATS-III, stationed at positions between 46 degrees W and 73 degrees W longitude.

The Applications Technology Satellites Meteorological Data Catalog: Volume V (Final), 1 August 1969 through 25 May 1970. Greenbelt, MD, National Aeronautics and Space Administration (NASA), Goddard Space Flight Center, October 1970. v, various paging. Available in The Schwerdtfeger Library: WC 879.59 A1 A45 v.5 (reference, noncirculating). Part I summarizes

NSSDC Master Catalog: The National Space Science Data Center (NSSDC) provides multidisciplinary data and information services, including a large digital data archive from past NASA space science missions along with directories, catalogs, and access to widely distributed science data resources.

Suomi, V.E. and Parent, R.J. Initial proposal to National Aeronautics and Space Administration for an ATS technological experiment. Madison, WI, University of Wisconsin-Madison, Department of Meteorology, Department of Electrical Engineering, 28 September 1964. UW SSEC Publication No.64.00.S1 (noncirculating).

Suomi, V.E. and Parent, R.J. Initial proposal to National Aeronautics and Space Administration for an ATS technological experiment. Madison, WI, University of Wisconsin-Madison, Department of Meteorology, Department of Electrical Engineering, 28 September 1964. UW SSEC Publication No.64.00.S1 (noncirculating).

Suomi, V.E. and Parent, R.J. Proposal: Spin scan camera system for a synchronous satellite prepared for the National Aeronautics and Space Administration. Madison, WI, University of Wisconsin-Madison, Department of Meteorology, July 1965. UW SSEC Publication No.64.00.S1 (noncirculating).

Suomi, V.E. and Parent, R.J. A proposal to the National Aeronautics and Space Administration for a spin scan camera system for the second ATS spin stabilized synchronous satellite (ATS-SASSE-2) (Amendment to contract NAS5-9677). Madison, WI, University of Wisconsin-Madison, Department of Meteorology, 29 November 1965. UW SSEC Publication No.64.00.S1 (noncirculating).

Suomi, V.E. and Parent, R.J. A proposal to the National Aeronautics and Space Administration for a supplement to contract NAS 5-9677 for research and development on a ground station system for the spin scan camera. Madison, WI, University of Wisconsin-Madison, Department of Meteorology, n.d. UW SSEC Publication No.64.00.S1 (noncirculating).

Suomi, V.E. and Parent, R.J. A proposal to the National Aeronautics and Space Administration for color spin scan camera for ATS-C. Madison, WI, University of Wisconsin-Madison, Space Science and Engineering Center, 15 September 1966. UW SSEC Publication No.64.00.S1 (noncirculating).

Suomi, V.E. and Parent, R.J. A proposal to the National Aeronautics and Space Administration for continuing support in research and technology using the ATS spin scan cloud camera. Madison, WI, University of Wisconsin-Madison, Space Science and Engineering Center, n.d. UW SSEC Publication No.64.00.S1 (noncirculating).

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Project Notes

The source documents, ATS-III transparencies and photographs, have been scanned "as is" so that the digital image represents the original. There is some variation in color because images have degraded at different rates. Color images were scanned from transparencies because they provided the most complete set. Color scanning and correction were outsourced to Burne Photo Imaging of Madison, Wisconsin. Black and white images were, and continue to be, scanned locally. Metadata for each image was extracted from the ATS Data Catalogs (Space Science and Engineering Center, University of Wisconsin-Madison) using ABBYY FineReader OCR (Optical Character Recognition) software. JPEG images are served online; with TIFF images stored off-line. All originals are stored in acid-free sleeves/envelopes and archival storage boxes.

The ATS image database site runs on an Apple server. Searches and retrievals are implemented with PHP to a MySQL database.

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