IKONOS – 2
IKONOS 2 satellite launched in September 1999 is the world's first
commercial satellite, offering high-resolution imagery. The IKONOS
sensor suite is capable of generating 1-m panchromatic and 4-m
multi-band images with off-nadir viewing up to 60º in any azimuth
for a better revisit rate and stereo capabilities. IKONOS orbits the
Earth once every 98 minutes at an altitude of approximately 680
kilometers. It constitutes a sun-synchronous orbit, and therefore the
satellite will pass over a given longitude at about the same local time
every day. This procedure allows relatively constant shadow angles on
subsequent image collections, helping to determine object’s height and
radiometric qualities of the image scene. In addition, by collecting
11-bit data it generates images with a high dynamic range of 2,048 grey
levels and yields a wealth of contrast information and shadow detail.
corrected satellite images can be used as navigational tools for
various environmental studies. To monitor volcanic activity after the
seismic crisis during 1996 – 1997 in Nisyros Island, located at the SE
part of the Hellenic Volcanic Arc, optical data from IKONOS 2 satellite
were used. This study was conducted within the framework of the
European Research Project GEOWARN (IST 1999 – 12310).
The Panchromatic Sharpening Image IKONOS 2 with one
meter resolution, for the Nisyros Island (Greece) was orthorectified to
produce the Ortho-IKONOS 2 Image.
the ortho-rectification of IKONOS a Digital Elevation Model (cell size:
2 m) was used as well as 38 selected ground control points (GCPs)
offering high accuracy. The latter were measured in (x,y,z) applying Geodetic
GPS receivers. An object to pixel space transformation using the
ground control points was computed using the polynomial mapping
functions of Kratky. An ortho-rectified image was produced with further
processing in the Hellenic Geodetic Reference System 1987 (HGRS’87).
This image will serve as a basic feature for a multi-disciplinary study
relating to Emergency Planning of Nisyros Volcano.
S., Hurni, L., Dietrich, V., Baltsavias, M., Pateraki, M., Lagios,
E.,Parcharidis, Is. (2002): Ortho-Photo Generation using IKONOS-2
Imagery and High Resolution DEM: A Case Study on Monitoring the
Volcanic Hazard on Nissyros Island (Greece), ISPRS Journal of
Photogrammetry and Remote Sensing, 57, 24-38.