Richard Morris Goldstein (April 11, 1927 – June 22, 2024) was an Americanradar astronomer and planetary scientist, who has been called "The Father of Radar Interferometry".
As a graduate student atCaltech in 1961, Goldstein used the antenna at theGoldstone Tracking Station to obtain the first realtime radar echos from the planetVenus.[2] By 1963, Goldstein and co-author had measured the period and retrograde rotation of Venus.[3] Using his same techniques, he confirmed Soviet experiments that acquired radar echoes fromMercury[4] and he was first to obtain echos fromMars in 1963.[5] In 1968, Goldstein was the first to obtain a radar echo from an asteroid, when he measured the radar cross section ofIcarus.[6] Later he also measured the size and rotational period of the nucleus of a comet.[7]
In 1964, Goldstein had analyzed the spectrum of radar echos from Venus to obtain the first images of features on the surface of that planet. Later, using range-Doppler and radar interferometric techniques, he was able to create some of the first maps of the planet.[8] Goldstein was also first to get echos fromGanymede[9] and later other moons ofJupiter.[10] He also detected Saturn's rings using radar.[11]
Goldstein began work in the mid-1980s on topographical mapping techniques usingsynthetic aperture radar. Initially using two antennas (and later a single antenna with a repeated track), he was able to use the phase interferometry to improve over stereoscopic optical mapping techniques.[12] Goldstein then developed his revolutionary "crabgrass growing" algorithm for phase unwrapping, which resolves ambiguities in phase data and isolates local noise and errors that would otherwise cause global errors.[13][14] This algorithm simplified the creation of accurate elevation maps,[15] and made possible many new applications for radar interferometry, including satellite detection[16] and quantification of small changes such as land subsidence,[17] ice flow motion,[18] ocean currents,[19] and geological fault shifts.[20] His subsequent work includes algorithms for mitigating thermal noise in the phase data, yielding dramatic improvements in the quality of measurement and phase data.[21]
In the 1990s, Goldstein also worked on applying radar techniques for detecting orbital debris. Previous radar approaches were able to detect orbiting objects as small as 5mm. By using short wavelength pulses and a separate antenna to detect echos, Goldstein was able to improve the detection of objects to less than 2mm at a 600 km altitude.[22] In the process, he discovered that the Earth has rings of debris (some apparently left over from theWest Ford Project). He continued to refine the technique, extending the capabilities to detect 3mm objects as far away as 3200 km.[23]
Goldstein was a regular participant and frequent award-winner in the annual JPL Invention Challenge.[24]
^Goldstein, RM; Jurgens, RF; Sekanina, Z (1984). "A RADAR Study of Comet IRAS-Araki-Alcock 1983D".Astronomical Journal.89 (11): 1745.Bibcode:1984AJ.....89.1745G.doi:10.1086/113683.
^Ostro, S. J.; Campbel, D. B.; Simpson, R. A.; Hudson, R. S.; Chandler, J. F.; Rosema, K. D.; Shapiro, I. I.; Standish, E. M.; et al. (1992). "Europa, Ganymede, and Callisto - New RADAR Results from Arecibo and Goldstone".Journal of Geophysical Research: Planets.97 (E11): 18227.Bibcode:1992JGR....9718227O.doi:10.1029/92JE01992.
^Zebker, H. A.; Goldstein, R. M. (1986). "Topographic Mapping From Interferometric Synthetic Aperture Radar Observations".Journal of Geophysical Research.91 (B5):4993–4999.Bibcode:1986JGR....91.4993Z.doi:10.1029/JB091iB05p04993.
^Zebker, Howard A.; Goldstein, Richard M. (1986). "Topographic Mapping from Interferometric Synthetic Aperture RADAR Observations".Journal of Geophysical Research: Solid Earth.91 (B5): 4993.Bibcode:1986JGR....91.4993Z.doi:10.1029/JB091iB05p04993.
^Li, F.K.; Goldstein, R.M. (1990). "Studies of Multibaseline Spaceborne Interferometric Synthetic Aperture RADARS".IEEE Transactions on Geoscience and Remote Sensing.28 (1): 88.Bibcode:1990ITGRS..28...88L.doi:10.1109/36.45749.
^Zebker, Howard A.; Rosen, Paul A.; Goldstein, Richard M.; Gabriel, Andrew; Werner, Charles L. (1994). "On the Derivation of Coseismic Displacement-fields using Differential RADAR Interferometry - The Landers Earthquake".Journal of Geophysical Research: Solid Earth.99 (B10): 19617.Bibcode:1994JGR....9919617Z.CiteSeerX10.1.1.37.4717.doi:10.1029/94JB01179.
