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. 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. In the early 1960s, the mainstay for obtaining this data at Canaveral was Convair's Azusa Mark I, a c-w cross baseline interferometer operating in the C band, requiring a transponder in the missile. Output data were digitized for use in the IBM 709 computer and measured parameters consist of range, coherent or fine range, and two direction cosines. 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. 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. Robert Weaver Robert Christian Weaver Sr., co-inventor of the AZUSA radar, was a Fresno native, graduated from the University of California Berkeley in 1938 with a bachelor's degree in electrical engineering. He joined the Army Air Corps in 1940, rising to major during World War II. He was responsible for radio and radar equipment in the China-Burma-India Theater. After World War II Weaver began his civilian career with what was then Consolidated Vultee Aircraft in 1946. "After the war he had a choice of engineering jobs; one in Los Angeles, the other in San Diego with Consolidated," his son said. With Convair, Weaver's assignments took him to Cape Canaveral and several other test sites. His specialty became designing radar, guidance and tracking systems for guided missiles and space vehicles. had a career in the aerospace industry that influenced the future of guided missiles and other space vehicles. In the early 1950s, Weaver and a colleague invented the AZUSA continuous wave tracking system, implemented at the Air