AIRBORNE INFRARED THERMAL DETECTION OF CAVES AND CREVASSES

Airborne infrared thermal scanners can be used to detect crevasses and cave openings, but only under certain conditions. First, the temperature inside the void must be significantly different from external conditions; and second, some mechanism must exist to bring this thermal difference to the surface where it can be detected by a scanner. Furthermore, it must be determined if other events influence this mechanism. In the case of crevasses, conduction and convection both play a role in altering the surface temperature of the snow bridge over a crevasse. For caves, convection is the mechanism that brings about the temperature alteration. Convection is linked to the breathing cycle which, in turn, is caused by changes in atmospheric pressure. From ground measurements of internal temperature, extgeranl temperature, and atmospheric pressure a flight time can be picked that will provide the most favorable circumstances. The cave signal is more of a problem because it is frequently surrounded by similar looking signals caused by other events. Results are given for a crevasse field in Greenland and for a cave system in Puerto Rico. /AUTHOR/

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00991112
• Supplemental Notes:
  • Presented at the Fall Meeting, American Society of Photogrammetry, Washington, D.C., September 1974.
• Corporate Authors:

  American Society of Photogrammetry

  105 North Virginia Avenue
  Falls Church, VA  United States  22046
• Authors:
  • Rinker, J N
• Publication Date: 1975-11

Media Info

• Features: Figures;
• Pagination: p. 1391-99
• Serial:
  • Photogrammetric Engineering and Remote Sensing
  • Volume: 44
  • Issue Number: 11
  • Publisher: American Society for Photogrammetry and Remote Sensing
  • ISSN: 0099-1112

Subject/Index Terms

• TRT Terms: Aerial surveying; Atmospheric pressure; Conduction; Convection (Fluid mechanics); Detection and identification; Detectors; Openings; Spacing; Surface temperature; Thermal imagery
• Old TRIS Terms: Barometric pressure; Crevices; Internal temperature; Thermal infrared imagery
• Subject Areas: Design; Highways;

Filing Info

• Accession Number: 00128480
• Record Type: Publication
• Files: TRIS
• Created Date: May 14 1976 12:00AM