Variations in surface roughness within Death Valley, California: Geologic evaluation of 25-cm-wavelength radar images

Abstract

Research Article| January 01, 1976 Variations in surface roughness within Death Valley, California: Geologic evaluation of 25-cm-wavelength radar images GERALD G. SCHABER; GERALD G. SCHABER 1U.S. Geological Survey, Flagstaff, Arizona 86001 Search for other works by this author on: GSW Google Scholar GRAYDON L. BERLIN; GRAYDON L. BERLIN 2Department of Geography, Northern Arizona University, and U.S. Geological Survey, Flagstaff, Arizona 86001 Search for other works by this author on: GSW Google Scholar WALTER E. BROWN, JR. WALTER E. BROWN, JR. 3Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91103 Search for other works by this author on: GSW Google Scholar Author and Article Information GERALD G. SCHABER 1U.S. Geological Survey, Flagstaff, Arizona 86001 GRAYDON L. BERLIN 2Department of Geography, Northern Arizona University, and U.S. Geological Survey, Flagstaff, Arizona 86001 WALTER E. BROWN, JR. 3Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91103 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1976) 87 (1): 29–41. https://doi.org/10.1130/0016-7606(1976)87<29:VISRWD>2.0.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation GERALD G. SCHABER, GRAYDON L. BERLIN, WALTER E. BROWN; Variations in surface roughness within Death Valley, California: Geologic evaluation of 25-cm-wavelength radar images. GSA Bulletin 1976;; 87 (1): 29–41. doi: https://doi.org/10.1130/0016-7606(1976)87<29:VISRWD>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Images — processed from 25-cm wavelength, side-looking airborne radar — of the salt flats and gravel fans on the floor of Death Valley, California, show distinctive variations in radar backscatter (that is, variations in image gray tones) that can be correlated with systematic changes in the surface roughness of different geologic units. Well-developed desert pavements on the oldest boulder gravel units of late Pleistocene age are clearly delineated as weak backscatterers on the images. A gradation in the size of gravel constituents near the base of the giant gravel fans is associated with an abrupt change in the backscatter energy. The change takes place at gravel radii between 0.08λ and 0.14λ (2.0 and 3.5 cm). A breakpoint observed in the Rayleigh scattering region of the total radar cross section is virtually independent of the antenna depression angle as long as the resolution area does not lie in the first pulse width of the echo (the 90° depression angle). With the longer wavelength radar systems, antenna depression angles of 45° to 90° appear to be well suited for investigations of surface roughness because of the suppression of radar shadows and the increased radar return from the near range. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.