ALPMON FINAL REPORT - ARC systems research

Contract ENV4-CT96-0359 ALPMON
level. For reaching an operational level it is essential to work with the data bases of the official
administrations. During the last years the administrations working with area related data are starting to
change data holding and data management from analogue to digital systems. This process is normally
combined with an update of existing data bases. On account of the large amount of data to be
transformed for an area as large as the alpine chain, this process will last for a couple of years.
The topics dealing with methodology development have to be addressed from scientists working in the
remote sensing and GIS domain like the consortium working together in the frame of ALPMON.
3.4.1 Satellite Sensors and Auxiliary Data
Working for ALPMON we have been forced to live with some unexpected limitations, from which the
missing of high resolution RS data was one of the most sever ones. ALPMON started with the expectancy
on high resolution satellite data. Most of the expected sensors failed. Only Ikonos was launched
successfully in June 1999, but still today non of the test areas of ALPMON was registered. Under this
conditions, the value adding effect of high resolution data sets is still an open topic.
The availability of high resolution remote sensing satellites in the near future will be an essential step
forward. The investigation proved, that at the envisaged scale of 1:25.000, the most urgent need for
thematic evaluations is in higher radiometric and temporal resolutions. Our hope is, that the high
geometric resolution systems announced will satisfy with respect to radiometric performance also. A list of
planned, failed and successful launched EO systems can be found under
http://www.itc.nl/~bakker/launch-table.html .
Table 21: Status of launches planned in 1998 (EARSeL Journal, 03.98)
Date spacecraft country best resolution success
20 March Spot 4 France 10 m March 1998
March Ikonos 1 USA, commercial 1 m Failed
after March Clark USA 3 m Failed
Quarter 1 CRSS 1 USA, commercial 1 m Failed
30 June EOS AM 1 (Terra
Sat)
USA 15 m December 1999
9 July Landsat 7 USA 15 m April 1999
mid EROS A USA/Israel 1 m
November Ikonos 2 USA, commercial 1 m August 99
Late Quick Bird USA, commercial 1 m Postponed
Late NMP/EO 1 USA 10 m, 315 bands postponed
End OrbView 3 USA, commercial 1 m Postponed
1998 CBERS 1 China/Brazil 20 m
E.g. for the monitoring of alpine pastures by means of classification very high resolution multi-spectral
scenes are demanded. Satellite images from IKONOS could be a solution. Yet, due to the lack of such
data, for the monitoring of landscape changes in the Tarvisio test site visual interpretation of aerial
photos from 1954 and the fusion image of 1992 has been necessary, as these data do not allow
automatic classification due to their radiometric properties. But, as described in section 3.1.2 and Table
19, visual interpretation is more expensive and time consuming than satellite image classification.
Sensor calibration coefficients: Delivery of in-flight calibration coefficients with each band, which is
needed for sensor calibration (see radiometric correction). Momentarily, this is only possible with the
acquisition of Landsat 7 data.
DEM: At the starting point of ALPMON, being aware of the fact, that DEM with the grid width requested
for an optimal topographic normalisation of 0,25 (4 times better) of the ground resolution of satellite data
are not available from the administration for the entire alpine chain, it was planned to investigate whether
this problem might be solved or at least approached by using DEM calculated from stereo on track
satellite data. To normalise data of the operational satellites of the Landsat, Spot or IRS class, MOMS-2P
stereo data sets have been assumed to be appropriate, promising DEM accuracy of around 6 m (pixel
size of the high resolution panchromatic band). For evaluating data of the high resolution systems
expected during the planning stage of ALPMON, the DEM calculation from Quick Bird stereo data sets
was envisaged. Unfortunately both systems failed, so during lifetime of ALPMON it was not possible to
check the real improvement by these opportunities.
Geocoding as well as topographic normalisation is strongly dependent on the accuracy of the available
DEM. The demand of a sub-meter DEM for correcting data with 1 m pixel size like the ones from the
JR, RSDE, ALU, LMU, Seibersdorf, WSL 86