de Jong, Steven 
  
THE DAIS LA PEYNE EXPERIMENT: USING THE OPTICAL AND THERMAL DAIS BANDS TO 
SURVEY AND MODEL THE SURFACE TEMPERATURE 
Arko LUCIEER', Eva KOSTER', Steven de JONG", Victor JETTEN" 
"Department of Physical Geography 
Utrecht University, the Netherlands 
A Lucieer@students.geog.uu.nl 
E.Koster@students.geog.uu.nl 
V.Jetten@geog.uu.nl 
" Departments of Geo-Information & Remote Sensing 
Wageningen Agricultural University & 
Utrecht University, the Netherlands 
s.dejong@geog.uu.nl 
KEY WORDS: Digital Airborne Imaging Spectrometer (DAIS7915), Hyper spectral imagery, Image correction and 
interpretation, Land cover, Surface energy balance, Temperature modelling. 
ABSTRACT 
In the summer of 1998, an experimental flight was carried out with the Digital Airborne Imaging Spectrometer 
(DAIS7915) over the Peyne test site in southern France. DAIS is a hyperspectral system with 72 bands from visible to 
shortwave infrared wavelengths and 7 bands in the thermal infrared. This study investigates the integrated use of 
thermal- and optical bands for extracting information from DAIS to simulate the thermal behaviour of the soil surface 
and the vegetation. Field survey during the days around the over flight time yielded information on the daily thermal 
cycle of various surfaces. Next a geostatistical sampling approach and interpolation algorithms were used to produce 
maps of soil properties controlling the thermal behaviour of the soil surface. Conditional simulation provided insight in 
the spatial distribution of the uncertainty of the soil properties. The field data showed that significant differences exist 
between the surface temperature of the various soil types and land cover. The optical DAIS images were converted from 
radiance into reflectance using the empirical line method. The uncalibrated digital numbers of the thermal DAIS bands 
were converted into absolute temperature values by using field measurements collected during the overflight. Next, the 
DAIS optical spectral bands were used to assess the vegetative cover and the land cover type on a pixel-by-pixel basis. 
A dynamic, spatial model was built simulating the surface temperature over 48 hours. Input for the model was extracted 
from the DAIS imagery and collected in the field. This model was calibrated by field temperature measurements. 
1 INTRODUCTION 
Soil temperature and soil moisture control to a large extent biological and chemical processes such as decomposition, 
nitrification, seed germination and root growth. Information on the spatial and temporal variability of surface 
temperature is important for various disciplines such as soil science and agricultural science. In the summer of 1998, an 
experimental flight was carried out with the Digital Airborne Imaging Spectrometer (DAIS7915) over the Peyne test 
site in southern France (Lucieer, 1999). During this flight, images of five flightstrips were acquired. The sensor collects 
images from the visible, near infrared and thermal infrared parts of the spectrum (table 1). The simultaneous 
combination of optical and thermal bands is unique for remote sensing observations at this scale. The high spatial 
resolution of approximately 6 by 6 m together with the high spectral resolution of 24 nm for the optical parts and 1.0 
um for the thermal part of the spectrum allows us to investigate the usefulness of the diagnostic absorption features and 
of the entire spectral shape for environmental applications. 
1 VIS/NIR 32 Si DC 0.4 — 1.0 
2SWIRI 8 InSb AC 1.5- 1.8 
3 SWIRI 32 InSb AC 2.0 — 2.5 
MIR 1 MCT AC 3.0— 5.0 
4 THERMAL 6 MCT AC 8.7 — 12.3 
Table 1: System characteristics of the DAIS 7915 spectrometer (Strobl, 1996a). 
    
  
International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000. 347