Engineering topics
Publications and source records attributed to Reid, M. S..
Work at the Jet Propulsion Laboratory had resulted in the development of a primary absolute cavity radiometer (PACRAD), which was recently accepted as an international standard of irradiance. The development of an wall-weather, field-worthy solar radiometer based on the PACRAD is discussed, and its calibration stability over a two-year period in the field is described.
The paper describes a precision insolation instrument - the Mark 3 Kendall Radiometer - developed for field survey work and for use as a calibration transfer standard. The instrument, which can be used to make accurate measurements of solar irradiance, has a windowless black cavity receptor mounted in a massive heat sink and has equal sensitivity to ultraviolet, infrared, and visible radiation. Attention is given to a calibration stability analysis over two years of operation.
The theory and experimental work which demonstrated the feasibility of conical-scan tracking with a 64 m diameter paraboloid antenna is documented. The purpose of this scheme is to actively track spacecraft and radio sources continuously with an accuracy superior to that obtained by manual correction of the computer driven pointing. The conical-scan implementation gives increased tracking accuracy with X-band spacecraft signals, as demonstrated in the Mariner Venus/Mercury 1973 mission. Also, the high accuracy and ease of measurement with conical-scan tracking allow evaluation of systematic and random antenna tracking errors.
The currently most-used insolation model and what improvements might be made in it to better suit it for use in designing energy systems is discussed. An approach to constructing an upgraded model is sketched.
An X-band low-noise receiving cone with 17-MHz instantaneous bandwidth was built to evaluate the 26-m antenna at the Venus Station (DSS 13), Goldstone, California, at X-band frequencies, and also to provide a means for precise radio source calibrations in this frequency range. These measurments are necessary to provide more accurate antenna gain performance calibrations for the 64-m antenna subnet. The zenith system temperatures with the cone on the ground and on the antenna are 17.5 and 20.8 K, respectively.
A data acquisition system set up at Goldstone was described. It is capable of recording a wide variety of parameters from widely separated geographical locations with varying integration times and recording speeds. It is fast, accurate, and modular in form so that it can be readily expanded. The accuracies of the system are discussed, and examples of data recorded with the system's capability of operation with preprocessing are given.
Programable system introduces correction factor to compensate for detector deviation from square-law response. If detector output voltage is V, the corrected output voltage is determined as V corrected = aV squared where 'a' is correction factor. Factor is determined and used automatically with digital computer techniques.
A broadband constant law detector was developed for precision power measurements, radio metric measurements, and other applications. It has a wide dynamic range and an accurate square law response. Other desirable characteristics, which are all included in a single compact unit, are: (1) high-level dc output with immunity to ground loop problems; (2) fast response times; (3) ability to insert known time constants; and (4) good thermal stability. The detector and its performance are described in detail. The detector can be operated in a programmable system with a ten-fold increase in accuracy. The use and performance of the detector in a noise-adding radiometer system is also discussed.
Compact device has wide dynamic range, accurate square-law response, good thermal stability, high-level dc output with immunity to ground-loop problems, ability to insert known time constants for radiometric applications, and fast response times compatible with computer systems.
The Deep-Space Network (DSN) consists of a worldwide network of 26- and 64-m antennas spaced approximately 120 deg around the world. The DSN is a precision communications system designed to communicate with and control unmanned spacecraft traveling at interplanetary ranges. Recent developments in the performance and evaluation of the antennas and maser receivers are discussed, and developments which have contributed to radio-science projects, such as planetary radar astronomy, very-long-baseline interferometry, pulsar, and other astronomical observations are described. It is also shown how these radio-science measurements have been used to evaluate the performance of the antenna-receiver systems.
Discussion of the effects of varying meteorological conditions on microwave propagation and on total system temperatures. Microwave atmospheric temperatures at X- and K-bands measured continuously for more than a year are compared with data obtained simultaneously by routine S-band spacecraft tracking.
Performance of high rate telemetry stations used in the Deep Space Network is verified. Measurement techniques are discussed.
Review of the performance capability at S-, X- and K-band of the NASA/JPL 64-m Cassegrain antenna at Goldstone, California. The multiple feed system allows X- and K-band atmospheric research studies to be conducted simultaneously with mission directed S-band spacecraft tracking. A description of the antenna system and its multiple operation is followed by gain and efficiency comparisons at the three frequencies. The total operating system temperature and its frequency dependence are discussed. Antenna gain and efficiency, and zenith system operating temperature are summarized at S- and X-band, respectively, by 62 dB, 63%, 16K; and 72 dB, 52%, 24K. Preliminary measurements for K-band are 76 dB, 39%, 29K.
System operating noise temperature calibrations of S band research operational cone at Venus Deep Space Station and polarization diversity S band cone at Mars Deep Space Station
Precision power measurements of spacecraft CW signal with microwave noise standards
Precision power measurements of spacecraft CW SIGNAL level with microwave noise standards, noting Mariner IV application
Precision DC potentiometer test for measuring microwave coaxial or waveguide insertion loss
Precision dc potentiometer microwave insertion loss test set for calibrating low noise microwave receiving systems used in space communications