813
EFFECT CF FLYING HEIGHT ON THE COLOR OF TARGETS
IMAGED ON COLOR INFRARED FILM
1 /
Jack H. Hansen
University of Missouri-Columbia, U. S. A.
ABSRACT
Color shifts associated with three flying heights above the
datum, namely 1500 feet (460 m), 6000 feet (1800 m) and 15000
feet (4600 m) are analyzed on two flight dates. Color meas
urements of imaged red, green and white targets on color infra
red film are made with a Leitz MPV microspectrophotometer and
specially written computer programs with color descriptions
given in 1960 CIE-UCS u,v uniform chromaticity scale coordin
ates. Color differences are statistically analyzed and anal
ytical densities are determined. The hue of all imaged tagets
shifted toward blue-green with increasing altitude when the
exposure was consistent with the Kodak recommended decrease in
exposure for increasing elevations. Generally, value and chroma
decreased with increasing altitude with differences in the effect
ive film exposure contributing to variations. Film exposure
differences caused target reflectance related color shifts,
therefore strict exposure control must be maintained where color
comparisons between different flights will be made. Also import
ant to photointerpreters is the color similarity found between
the imaged targets on photography taken at the same altitude but
on different dates. This suggests that photography flown on
different dates may be compared directly, altitude for altitude,
when taken under similar atmospheric conditions, exposure and
time of day.
ZUSAMMENFASSUNG
Farbschwankungen verbunden mit drei Flughöhen, nämlich 1500 Fuss
(460 m), 6000 Fuss (1800 m) und 15000 Fuss (4600 m) werden für
zwei Flugdaten analysiert. Mit Hilfe eines Leitz MPV Mikrospek
trophotometers und eines speziell entwickelten Computer-Pro
grammes, dessen Farbbeschreibungen in CIE 1960 u,v einheitlicher
Farbenskala gegeben sind, werden Farbmessungen der auf dem Infra
rot Farbfilm rot, grün und weiss abgebildeten Objekte gemacht.
Farbunterschiede werden statistisch analysiert und analytische
Dichten werden bestimmt. Die Färbung aller abgebildeten Objekte
verschob sich mit zunehmender Höne zu blau-grün, wenn die Belicht-
J. H. Hansen presently is Associate Professor of Civil Engineering
University of Tennessee Space Institute, U. S. A.