Engineering:AZUSA
AZUSA refers to a ground-based radar tracking system installed at Cape Canaveral, Florida and the NASA Kennedy Space Center. AZUSA was named after the southern California town Azusa, California where the system was devised in the early 1950s.
Radar interferometry
Within a year,[when?] NRL reports from the Viking program were diagramming ground-based tracking interferometers, which relieved the Viking of the burden of signal-processing equipment by computing the missile's position from the ground. Two precursors of Minitrack were evident in the interferometer arrangement. First, only a tiny radio beacon needed to be carried on the Viking itself, an important feature of the Vanguard "Minitrack," in which the prefix 'Mini" applied to the minimum-weight satellite transmitter. The second precursor was the "Lff arrangement of the interferometer antennas which persisted in some early designs of Minitrack, although the final deployed version extended the bars of the "L" to make a cross.[1]
USAF Atlantic Missile Range, Cape Canaveral, Florida
For some scientific satellites "achieving orbit" is enough, but vehicles carrying men or payloads that must be placed in precise positions, such as geosynchronous satellites, require improved trajectory position and velocity measurement systems.[according to whom?]
The Azusa II, intended to replace Azusa I, was installed in 1961. It is nearly identical to the Mark I except that its circuit design was refined and cosine rate was added which provides better direction cosine information. Both Azusas have identical limitations: they will not track cross-polarized signals; missile antenna nulls deeper than 10 dB cause noisy data, ambiguities and, in severe cases, loss of data.[2]
Use in Apollo Program
The AZUSA tracking radar was used to monitor initial phases of launch for the Saturn S-II by telemetry with transponder frequency of 5,060 MHz (receiver) and 5,000 MHz (transmitter) with 2.5 W of power.[3]
Robert Weaver
Choosing the San Diego assignment, Weaver made his home in La Jolla. He was familiar with the area from a 1933 visit to La Jolla Shores, where he had camped out with friends in cow fields, per his son. Computers, electronic gadgets and photography occupied much of his leisure time. He also enjoyed sports cars, as well as "the green flashes of the La Jolla sunsets and the breathtaking beauty of Yosemite Valley," his son said.[4] Weaver, whose engineering career with the Convair Division of General Dynamics spanned 35 years, died age 87 in September 2003 at the White Sands of La Jolla retirement community. He died of natural causes, per his son, Robert Weaver Jr.
References
- ↑ Corliss, William R., 'The Evolution of the Satellite Tracking and Data Acquisition Network (STADAN)'. Goddard Historical Note No. 3. Greenbelt, MD.: Goddard Space Flight Center, 1967.
- ↑ Earth-based Electronics in Electronics, vol. 34, no. 46, pp. 108-118, 17 November 1961.
- ↑ F.O. Vonbun, 'Ground Tracking of the Apollo', NASA Report N66-22219, 1966.
- ↑ Jack Williams. Robert Weaver; Inventor of missile-tracking system. San Diego, California Union-Tribune, September 25, 2003.
Further reading
- Corliss, W. R. 'Evolution of Satellite Tracking and Data Acquisition Network STADAN from pre-IGY AND Minitrack facilities'. NASA Goddard Space Flight Center. Report Number: GHN-3, NASA-TM-X-55658, X-202-67-26, 1967.
- General Dynamics/Astronautics; AZUSA. A Precision, Operational, Automatic Tracking System. San Diego, California, NTIS Report No. AD0832153, MAR 1959.
- IBM, Astrionics System Handbook, revised ed., NASA MSFC No. IV-4-401-1, NTIS Doc. N70-70002, 1 November 1968, 418 pp. (International Business Machines Corporation working under NASA Contract NAS8-14000).
- Robert V. Werner, Robert C. Weaver, and James W. Crooks Jr. Transmitter-Receiver. Patent number: 2972047, Filing date: November 21, 1955, Issue date: Feb 1961.
- Robert V. Werner, Robert C. Weaver, and James W. Crooks Jr. Positioning Determining Device. Patent number: 3025520. Filing date: November 21, 1955. Issue date: Mar 1962.
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