title: Comparison of diurnal contrast changes for millimeter-wave and infrared imagery.
abstract: Far-infrared outdoor imagery has a lower contrast in the morning/afternoon relative to the highest contrast, which is observed at 14:00. Millimeter-wave (mmW) imagery can also follow this pattern. However, in this paper, we show that the opposite can occur for mmW imagery, wherein a higher contrast can occur in the morning/afternoon and lower contrast at 14:00. To this end, we show that a wood and rubber sample are observed to have a difference in mmW radiometric temperature of 17 degrees C at 9:00 and a difference of only 7 degrees C at 14:00. Details of our observations are presented.
authors.affiliation: Department of Electrical and Computer Engineering, University of Delaware, Newark, Delaware 19716, USA. jwils@udel.edu
authors.forename: John P
authors.initials: JP
authors.lastname: Wilson
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Mackrides
authors.forename: Jesse P
authors.initials: JP
authors.lastname: Samluk
authors.forename: Dennis W
authors.initials: DW
authors.lastname: Prather