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APPLICATION OF THERMAL DATA
TO SOIL MOISTURE CALCULATION AND TO SOIL MAPPING
J. Nithack
DFVLR, 8031 Oberpfaffenhofen, F.R.G.
Introduction
Many attempts have been made to calculate soil moisture utilizing ther-
mal properties of soils and thermal IR-data (8-14 u). But no useful
results were achieved till now [1] especially concerning quantitative
values of vegetated areas.
Therefore during the years 1974-1976 a measurement program was carried
out at the Zentralstelle für Geo-Photogrammetrie und Fernerkundung,
Munich, to answer the following question:
Is it possible to caluclate the water contents of vegetated soils uti-
lizing thermal IR-data?
During those studies another problem arose: to which degree thermal
data can help in mapping soil differences,
For the basic research test area IV of the German airborne remote sen-
sing program (FMP) offers nearly ideal natural conditions. The test
area is situated south of Munich between the Starnberger See and the
margin of the alps (fig. 1).
Two smaller measuring areas were selected:
- test area Iffeldorf with homogeneous soil, with similar vegeta-
tion (besides woods almost only grass) and with small scale va-
riations of soil moisture.
- test area Kochel Moos with nearly constant soil and moisture con-
ditions but with variations of vegetation and status of vegeta-
tion (grass).