Engineering topics
Publications and source records attributed to Goldstein, R. M..
Radar observations of Toro were made with a (one-dimensional) resolution of 0.005 arc sec. When radar and optical data are combined, they suggest an irregular rocky surface slightly smoothed by a mantle of loose material.
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Taking advantage of the favorable opposition of 1971, the Goldstone radar system, operating at 2388 MHz, was used to scan the Martian surface. Measurements of altitude and reflected power were taken approximately every 3 days. Each measurement represents an area 8 km E-W by 80 km N-S, the highest resolution attained to date. Altitude measurements obtained on different observing days were combined to produce altitude profiles for three complete rotations, each at different latitudes. Large-scale variations in altitudes cover a range of 14 km. Altitude changes of 5 in 30 km of longitude were observed. The altitude profiles show the heavy cratering of the surface, and several large craters (50-100 km) 1-2 km deep are easily seen.
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Radar scans of Venus have yielded a brightness map of a large portion of the surface. The bright area in the south (alpha) and the twin such areas in the north (beta and delta) were first discovered by spectral analysis of radar echos. When range-gating is also applied, their shapes are revealed, and they are seen to be roundish and about 1000 km across. Although radar brightness can be the result of either intrinsic reflectivity or surface roughness, polarization studies show these features to be rough (to the scale of the wavelength, 12.5 cm). Dark, circular areas can also be seen, many with bright central spots. The dark areas are probably smooth. The blurring of the equatorial strip is an artifact of the range-Doppler geometry; all resolution disappears at the equator. Another artifact of the method is the 'ghost', in the south, of the images of beta and delta. Such ghosts appear only at the eastern and western extremes of the map.
Radar observations of a narrow belt of the surface of Mars, centered at 16 deg south latitude, show a very rugged terrain, with elevation differences greater than 13 kilometers from peak to valley. For nearby points, the relative altitude is measured to 40 meters at best; the precision is worse for points at different latitudes, or widely separated in longitude, because of orbital uncertainties. Some of the larger craters have been resolved, and their depth and, in some cases, the height of the raised rim have been measured. Where high resolution photographs are available, the correlation is excellent.
Pure monochromatic waves of a wavelength of 12.5 cm were beamed toward the planet. The echoes were no longer monochromatic because of the Doppler effect of the planet's rotation. A Fourier power spectrum was produced from the echo signals. On the surface of Mercury, the contours of constant Doppler shift are circles, concentric about a point on the limb near the equator.
Quasar internal kinematics and fine structure rapid time variations from radio interferometry
Venus radar brightness map, using 40 km separation between range gates and comparable distances between Doppler slices
Mercury surface features from spectrograms of depolarized radar echoes
Venus and Mercury radio and radar studies concerning brightness temperature, surface reflectivity and planetary motion
Mars radar results during 1969 opposition, presenting elevation and radar brightness as function of longitude
Pioneer 6 radio signal spectrograms during solar occultation, noting solar event effects on bandwidth
Transmitter, radiating at a right angle to the spacecraft trajectory and intersecting the surface at a shallow angle, yields accurate radar maps of lunar or planetary surfaces. Earth based station receives the signal reflected from the planetary surface. Mapping coordinates and signal strength are produced by earth based transmitter.
Icarus radar and optical observations indicating surface smoothness differences between central and higher latitudes, radius size and radar reflectivity
Radar observation of Icarus at time of close approach, giving values of radius, rotation period and Doppler shift derived from spectrograms
Venus radius determined by planetary radar and Mariner 5 radio tracking data
Radar round trip time of flight measurements to Venus for three month interval about inferior conjunction of August 1968