trated with drawings, photographs, block diagrams, and graphs of performance data. The PAR-80 antenna is a 3.81 X2.13-m 85 X 176-element array of slotted waveguides with phase shifters (for + or — 15-deg azimuth steering) and a planar three-skin transmission-type circular polarizer; it provides improved coverage, resolution, accuracy, and clutter performance superheterodyne receiver, a coaxial-magnetron transmitter (9.0-9.16 GHz, peak power 180 kW, pulse width 240 nsec, repetition rate 3450 pulses/sec), a time-compression video processor, and display hardware (18.5-km logarithmic and 37-km linear range scales). Selected environmental and operational test results are shown. (T.K.) Source of Abstract (Subfile): AIAA/TIS Descriptors: ‘AIRCRAFT INSTRUMENTS; ‘AUTOMATIC LANDING CONTROL; ‘NAVIGATION AIDS; ‘RADAR APPROACH CONTROL; ‘RADAR SCANNING; ANGULAR RESOLUTION; ANTENNA RADIATION PATTERNS; CIRCULAR POLARIZATION; DISPLAY DEVICES; ENVIRONMENTAL TESTS; INSTRUMENT ERRORS; POWER GAIN; RADAR ANTENNAS; RADAR BEAMS; RADAR NAVIGATION; TRANSMITTER RECEIVERS Subject Classification: 7504 Aircraft Communications & Navigation (1975- ) Analysis of helical brush commutation MONGEAU, P. (Electromagnetic Launch Research, Inc., Cambridge, Ma) (Institute of Electrical and Electronics Engineers, Symposium on Electromagnetic Launch Technology, 2nd, Boston, MA, Oct. 10-13, 1983) IEEE Transactions on Magnetics (ISSN 0018-9464), vol. MAG-20, March 1984, p. 231-234. 7 Refs. Contract No.: DAAK10-83-C-0025 Language: English. Country of Origin: United States. Country of Publication: United States Document Type: JOURNAL ARTICLE Most documents available from AIAA Technical Library Journal Announcement: IAA8414 Coaxial launchers are one type of electromagnetic accelerators which employ a pair of coaxial coils to generate a solenoidal field. A stationary coil generates a magnetic field which interacts with the field of a coil which is attached to the projectile. All coaxial launchers require some form of synchronization to align the fields of the two coils. A continuous helix is used as the drive coil in one practical method. Sliding brushes attached to the projectile excite a limited section of the drive helix. The projectile coil is excited by conventional slip rails or, possibly, inductively. This type of accelerator is called a helical launcher, and represents simply a linear de electric motor. It is shown that the operating efficiencies of a brush commutated helical launcher can be determined by analyzing the various inductive couplings of the system. Attention is given to details of helical commutation, energy transfer, kinetic energy transfer, transfer efficiency, and commutation voltage. (G.R.) Source of Abstract (Subfile): AIAA/TIS Descriptors: * ACCELERATORS; ‘BRUSHES; ‘ELECTROMAGNETIC PROPULSION; ‘LAUNCHERS; COMMUTATION; ENERGY CONVERSION EFFICIENCY; ENERGY TRANSFER; EQUIVALENT CIRCUITS; KINETIC ENERGY; MAGNETIC COILS Subject Classification: 7533 Electronics & Electrical Engineering (1975- )
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