' -
fing 2008
MAPPING OF LITHOLOGICAL UNITS OF Q AN KIRI BASIN, CENTRAL ANATOLIA,
TURKEY WITH PROBA CHRIS HYPERSPECTRAL DATA
H. Ozen 2, *, N. Musaoglu b , O. Tiiysuz c ,
a TUBITAK UZAY, METU Campus, 06531 Ankara, Turkey, hilal.ozen@uzay.tubitak.gov.tr
b ITU, Geodesy and Photogrammetry Department, Civil Engineering Faculty, 34469 Maslak, Istanbul, Turkey.
nmusaoglu@ins.itu.edu.tr
c ITU, Eurasian Institute of Earth Sciences, 34469 Maslak, Istanbul, Turkey, tuysuz@itu.edu.tr
KEY WORDS: Mapping, Hyperspectral, Field Spectroscopy, Laboratory Spectroscopy, Calibration, Proba CHRIS Image Data
ABSTRACT:
Remote sensing provides a valuable basis for regional geological mapping. This study aims for the mapping of lithological units in
Eldivan-Qankiri part of Rankin Basin using hyperspectral remote sensing. A Proba (Project for On-Board Autonomy) CHRIS
(Compact High Resolution Imaging Spectrometer) Level 1A hyperspectral satellite image of the study area is provided by European
Space Agency (ESA) as a Category-1 LBR (Low bit rate) project for the mapping purposes. A field spectroscopy study at a time
close to the overpass of the Proba CHRIS satellite has been carried out. Besides, hand specimens have been collected at some sites
for laboratory spectroscopy study. Quantitative and qualitative information on reflectance properties of geological materials of
Qankin Basin are extracted from image, field and laboratory spectroscopy study.
INTRODUCTION
Hyperspectral images can stimulate unique geologic insights in
mapping. This paper covers the utilization of Proba (Project for
On-Board Autonomy) CHRIS (Compact High Resolution
Imaging Spectrometer) hyperspectral image for the
discrimination of geological features and mapping purposes. In
this study, the European Space Agency (ESA) provided the
hyperspectral satellite image, Proba CHRIS Level 1A, of
Eldivan-Qankiri part of Qankin Basin as a Category-1 LBR
(Low bit rate) project. A field spectroscopy study at a time
close to the overpass of the Proba CHRIS satellite has been
planned and carried out. During the field study hand specimens
have been collected at the site for the laboratory spectroscopy
study. The satellite data, field and laboratory spectroscopy data
are integrated for the processing of the hyperspectral data.
The study area, Qankin Basin is located in Central Anatolia. It
is one of the largest Tertiary basins in Turkey. It is a unique
area to study lithological units resulting from subduction and
collision processes. It is an easy accessible site. The basin is
sparsely vegetated.
The geology and tectonic relations of Qankiri basin have been
studied and mapped in previous studies by Dellaloglu et al.,
(1992) and by Tiiysiiz et al., (1992, 1993, 1995). The most
recent study in Qankiri basin is a geological remote sensing
study by Kaymakgi (2000). He has mapped the lithological
units in the basin using Landsat TM images.
PROBA CHRIS
The Proba satellite is launched on October 2001. The satellite
has two earth observing instruments HRC (High Resolution
Camera) and CHRIS. Since 2004, Proba is operated by ESA
Redu Ground Station in Belgium. Its CHRIS instrument, is
Corresponding author.
funded by the British National Space Centre (BNSC), has been
built by SIRA Space, UK.
The earth observing instrument CHRIS has a swath width of 14
km. CHRIS has 5 different acquisition modes. The mode 1
image data has 62 spectral bands and a 34 m spatial resolution
at nadir at 556 km. It is within the spectral range of 405 nm -
1009 nm and has 7.5 nm as nominal bandwidth. The mode 2, 3,
4 image data have 18 spectral bands and mode 5 has 37 bands
with 17 m spatial resolution at nadir. At each mode 5 images of
the same area are taken with various acquisition angles: -55, -36,
0, +36 and +55.
FIELD SPECTROSCOPY STUDY
The most essential part of this study has been the planning of
the field study. This had to be done during the ESA Category -1
project proposal. First, the Proba CHRIS image acquisition date
has been planned as to be suitable for the field spectroscopy
study and the weather conditions of Central Anatolia. Second,
the area has been chosen to be easily accessible, lithological
diverse and not cover an urban area.
It is important for field spectroscopy to measure an area of
ground within the image at the time that the satellite passes
overhead, or at least at a time close to the overpass. The
acquisition date of the image requested is fixed to be as cloud
free as possible and suitable for field spectroscopy study. In
Central Anatolia this is usually Mid-Summer. So, the field
study is planned at 21-27 July 2006 and the overpass of the
satellite any day within. The exact day of the satellite overpass
has been declared two days before the acquisition to be on the
25.07.2006 by ESA.
During the field study a field spectrometer, ASD FieldSpec
HandHeld Pro is used to characterize the reflectance of the site.
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