Thermistor validation and path radiance effects in ship thermal image measurements
Wood, David S.
Milne, Edmund A.
MetadataShow full item record
Thermal images in the 8-12 /xm band were taken of the research vessel R/V POINT SUR in the Monterey Bay on 7 May 1991. The images were recorded using the AGA Thermovision 780 with an IBM AT computer using CATS 2.1 software. Corrections for computed transmittance, path length, and emissivity were made to the image files utilizing the locally developed computer program AGACATS. Temperature measurement distributions made with the AGA 780 compared to thermistor measurements of the ship temperatures were found to be extremely close (within one degree) at ranges of one half mile and one mile. PC-TRAN in the radiance mode was than used to compute the path radiance to the ship and compared with the path radiance correction in the AGA 780 algorithm. The AGA measurements varied over the range from twenty-five to seventy-five percent while the LOWTRAN fraction ranges only from seventy-five to eighty-five percent with the biggest discrepancy occurring at the short paths. The predicted path radiance as computed using LOWTRAN 6 did not fall off as much with decreased slant range as the AGA path radiances. This difference may be attributed to problems with either the AGA algorithm or the LOWTRAN code, or with the accuracy of the inputs. A contributing factor may be the time delay of one to one and a half hours between the image data and the radiosonde balloon launch.
Approved for public release; distribution is unlimited
Showing items related by title, author, creator and subject.
Moss, Eric Brian (Monterey, California. Naval Postgraduate School, 1992-09);Measurements of sea surface radiance were made in the 2-5.6 and 8-14 um wavebands near the azimuth of the sun at low solar observation angles. From these measurement, an analysis of the statistical and physical nature of ...
Karavas, Panagiotis (Monterey, California ; Naval Postgraduate School, 1999-06);Until recently no standard atmospheric propagation codes included the effects of polarization. Recently a research grade upgrade to MODTRAN (Zeisse, Nrad) has allowed the polarized case. This upgrade, called SEARAD, ...
Investigation of minimum resolvable temperature difference formulation for polarized thermal imaging range prediction Guimaraes, Edson F. C. (Monterey, California ; Naval Postgraduate School, 1999-09);Previous measurements have demonstrated that a polarization filter can increase ship-background temperature contrast in the infrared, while decreasing the received radiance. Application of this technique to increasing range ...