Engineering topics

Whalen, A. A.

Publications and source records attributed to Whalen, A. A..

6 records

NASA NTRS1979

Public service communications

The purpose of the paper is to construct, for detailed analysis, satellite and terrestrial communications delivery system models. Attention is given to the Public Service Communications Delivery System Architectural Study, that takes advantage of the extensive experience which exists among the public service experimenters. The Application Test Pilot is examined, which is a program designed to help awareness, in a practical sense, of the technology available and by the users innovative talents, adapts the technology to solve their problems.

Whalen, A. A.↗

NASA NTRS1975

ATS-6 - Technical aspects of the Health/Education Telecommunications Experiment

An overview is given of the HET experiment on ATS-6. The paper is divided into nine parts, including a technical overview, a preliminary evaluation of the HET demonstration, a review of operations at the Denver uplink terminal, a discussion of remote ground terminals, a review of C-band comprehensive terminals and of S-band comprehensive terminals, and parts devoted to general network operations, technical management and effectiveness of the network, and the site equipment operator.

Boor, J. L.↗

NASA NTRS1975

ATS-6 - A satellite for human needs

On May 30, 1974, NASA launched the ATS-6 experimental communications satellite into a geosynchronous orbit at a station centered over the United States. The 1400 kg satellite was designed to be body-stabilized with a 3-axis control system capable of precision offset pointing. It deployed a 9.1 meter (30 foot) parabolic reflector antenna with a transponder that covered a frequency range from VHF through C-band. The high RF gains obtained with the antenna were to be used for many dramatic communications experiments, one of which was the Health/Education Telecommunications Experiment (HET), a demonstration of direct broadcast of color television to low cost terminals in remote regions of the United States. More than 120 terminals with 3-meter antennas were deployed in Alaska, Washington, the Rocky Mountains, and Appalachia to provide educational and health services to selected community centers. After 11 months of nearly continuous service, the performance of both the satellite and the experiment have exceeded all expectations.

Whalen, A. A.↗

NASA NTRS1975

Health Education Telecommunications Experiment

The Health/Education Telecommunications Experiment carried out with Applications Technology Satellite-6 is described. The experiment tested the effectiveness of color television broadcasts to over 120 low-cost receivers in rural areas. Five types of earth stations were involved: receive-only terminals (ROT), an intensive terminal consisting of the ROT plus a VHF transmitter and receiver; comprehensive S and C-band terminals having the capability of transmitting the video signal plus four audio channels; and the main originating stations. Additional supporting elements comprise 120 video receive terminals, 51 telephony transceivers, and 8 video originating terminals of 3 different parts. Technical parameters were measured to within 1 dB of the calculated values.

Whalen, A. A.↗

NASA NTRS1975

Health education telecommunications experiment

The Health/Education Telecommunications Experiment (HET) was conducted jointly by NASA and HEW on NASA's ATS-6 communications satellite. This experiment actually consisted of six experiments testing health and education applications of a communication spacecraft producing a broadcast of color television directly from space to over 120 low-cost receivers located in remote rural areas throughout the U.S. (including Alaska). The experiments were conducted over the period from 2 July 1974 to 20 May 1975 and operated on an almost daily basis. The overall telecommunications system to support these experiments consisted of many elements: The ATS-6 spacecraft; five different types of earth stations consisting of 120 video receive terminals, 51 telephony tranceivers and eight video originating terminals of three different types. Actual performance of the equipment as measured in the field was shown to equal or exceed predicted values.

Whalen, A. A.↗

NASA NTRS1973

Health/education telecommunications experiment

The use of ATS 6 spacecraft in a general telecommunication link for the health/education experiment demonstrates the feasibility of the small receiver-only terminal consisting of a ten foot diameter antenna located on a three-legged mount. The terminal is capable of 0 to 70 degrees elevation, course adjustment, and a plus or minus 5 degree elevation vernier adjustment. Its tuned radio frequency receiver utilizes a cavity back dipole feed and a preamplifier. The indoor unit provides further RF gain and drives a wideband limiter-discriminator.

Whalen, A. A.↗