A low risk experiment to determine the principal properties (density, pressure, temperature) of the Martian atmosphere has been studied. A. slender conical capsule is ejected from the Mars fly-by or orbiting spacecraft and enters the planet’s atmosphere. Theoretical and experimental data support the concept of continuous communication between the sharp cone capsule entering the Martian atmosphere and the spacecraft. The communications system basically consists of a 25 watt transmitter phase modulating a 100 mc carrier on the entry capsule and a wideband receiver on the spacecraft. Transmitting power and spacecraft data storage considerations resulted in a data transmission rate of 147 bits per second in a pulse code modulated format.

The advent of requirements for nuclear radiation hardened telemetering components is accompanied by numerous technological problems. Future vehicles may impose severe environmental problems on a telemetering transmitter, as well as the need for relatively high r. f. power output. This paper describes the development of a nuclear radiation hardened telemetry transmitter, designed for operation in the 1435-1535 MC/S band at a nominal 100 W average R.F. power. The development phases covered in the paper consist of (1) design and radiation test of three low power transmitter exciters, (2) design and test of three transmitters, including the 100 W power amplifier and circuit modifications as dictated by radiation test, and (3) change in selection of the final R. F. tube. The paper includes a description of the resultant developmental transmitter, some comments on the major radiation effects problems, and some of the considerations in the radiation test of the transmitter. The author concludes with current status remarks.

The dual polarized high-power synthetic conical scan tracking system was designed for operation over the frequency range from 1700 to 2400 mc. This feed was developed for an existing 33' parabolic reflector which is presently located at the Floyd Test Site in Rome, New York. The feed network is located at the focal point of a parabolic dish and is fabricated in WR-430 waveguide. The system provides a horizontally polarized on-axis beam for transmission. It also provides two conically scanning receiving beams at a frequency different from the transmit frequency. One of the receiving beams is vertically polarized; the other is designed to receive the orthogonal horizontal polarization. The conical scan is synthetically generated and individual channel control is provided to allow the two receiving beams to be aligned. The feed system may be converted to provide monopulse outputs by simply removing the synthetic conical scanning mechanism.

The increased use of L and S-Band for telemetry services in conjunction with the need for miniaturized equipment, points up the desirability for compact transmitter units. This report describes a miniature S-Band transmitter and its associated power supply. The design goals are presented together with a discussion of the technical approach used to meet the severe requirements. Illustrations and performance data are included for completeness.

This paper describes a telemetry transmitter designed for the 2.2-2.3 Gc band. Design philosophy followed to achieve minimum size, wide deviation capability, high reliability and high efficiency are discussed in detail. The paper presents extensive measured data to indicate achievement of design goals set by IRIG 106-60 and ARTC-34. Construction details of the transmitter are illustrated.

It is common knowledge that the matched filters for signals in white noise have impulse responses whose time duration is exactly as long as that of the input signal. Nothing can be gained by extending the response of the matched filters to longer than one bit unless (1) the signal source is coded, or (2) the noise spectrum is rising or at least is other than white-Gaussian-ergodic. This paper discusses means of improving bit error rates without coding the source. There are essentially two ways of extending the integration time of the matched filters, each of which offers an improvement in signal-to-noise ratio. The first way is to extend the response directly to more than one bit but constrain the filter to give zero or some small pre-assigned intersymbol crosstalk. The second way is to build matched filters for multiple bits. Both techniques can be used simultaneously; i.e., matched filters can be constructed for bit patterns, and the responses can be extended to longer than the baud to which the filters are matched. Once again this extension is done under the constrain of zero or little crosstalk. In this paper, the matched filters for several examples are expanded in a rapidly converging series, each term of which is identifiable with a known network. For the cases where the shape of the noise is not known analytically, an experimental technique is given for determining sufficient statistics of the noise so that the optimum matched filters can be designed.

The effects of interference and capture in FM reception are reviewed for the purpose of determining the basis for characterizing and measuring the capture performance of FM receivers. Capture performance criteria and performance measurement techniques are proposed for application to FM telemetry receiver evaluation.

Employing a team composed of physicians, electrical engineers, and specialists in physical education, significant dynamic physiological data has been gathered by means of radiotelemetry from athletes undergoing strenuous effort, participating in team sports, and from spectators viewing football games. Using a transistorized A.M.-F.M. transmitter carried in a padded compartment strapped comfortably onto the low back and weighing 30 oz. complete, ECG, pulse, temperature and respiration signals have been transmitted for distances up to 500 yards. The multiple technical problems surrounding distance telemetering of physiological information during active and vigorous muscular effort are discussed. Somatic muscle interference, the most troublesome artefact in dynamic electrocardiography, has been successfully circumvented by instantaneous recording of data from the momentarily inactive subject. Application of computer techniques to the analysis of exercise electrocardiograms must await procedural improvement and standardization and collection of adequate data on which to base valid programming.

An experimental evaluation program was undertaken to investigate the feasibility of expanding the IRIG (Inter-Range Instrumentation Group) FM/FM baseband. The results of the evaluation indicate that with typical field equipment, three higher-frequency proportional-bandwidth channels can be added to the baseband while maintaining adequate system performance.