Symposium on Remote Sensing for Resources Development and Environmental Management/ Enschede /August 1986
© 1987Baikema, Rotterdam. ISBN 90 6191 674 7
1055
Working Group 2: Microwave data
N.Lannelongue
Chairman
G.P.de Loor
Rapporteur
During this symposium Working Group II had two
sessions and one poster session as well as one ses
sion in combination with WG V (Geology). The two
sessions (attended by 30-35 persons) mainly dealt
with image handling and the interpretation of basic
radar backscatter measurements. The poster session
and the combined session dealt with radar image
evaluation and thematic interpretation. So the
papers presented showed a large variety.
1 CONCLUSIONS AND RECOMMENDATIONS
Since there exists still an intensive scientific
research activity in microwave remote sensing the
state of the art is different for the different ap
plication areas.
1.1 Agriculture and vegetation
Although the area is still under scientific inves
tigation the subject was well covered by a large
number of presentations. Multitemporal observation
is effective for crop identification and monitoring.
This is enhanced by using 2 incidence angles. Two or
three observations, 10 days up to one month apart,
are adequate. Multifrequency observation has not
demonstrated any quantitative improvement until now.
It is recommended to continue the development of
suitable models and to study the relation between
existing climatological growth models and the avail
able radar data bases for the evaluation of the
radar monitoring function.
1.2 Geology
In this area the penetration of decimeter and meter
waves in dry sand was confirmed. It was also con
firmed that the observation of lineaments is highly
influenced by the azimuth direction. In relation to
satellite design it is therefore recommended to take
advantage of the possibility to use different angles
of observation in azimuth.
To reduce the effect of the vegetation cover and
to increase penetration depth frequencies in L-band
or lower have to be preferred. The incidence angle
must be steeper than with Seasat.
1.3 Forestry
The first interesting paper on quantitative measure
ments and modelling was presented. This work has to
be continued and generalized in order to include
different trees, better description of trees and
seasonal effects.
1.4 Oceanography
Although a lot of work is done in this field there
were no presentations on this subject. Specific in
strumentation is developed for this application in
order to take advantage of the features of the sea
surface (altimeter, wind scatterometer and wave mode
SAR). Obviously this material is presented on special
symposia.
1.5 Cartography and topography
An interesting quantitative evaluation was presented
of the capabilities of radar for topography restitu
tion using 2 radar stereo images.
2 REMARKS
1. The combined meeting with Working Group V has
demonstrated the usefulness of combined activities
and collaboration with other Working Groups. A collo
quium of WG II and III is now being considered for
January 1988.
2. A gap continues to exist between the fundamental
research and the user oriented interpretation work.
Pilot experiments mixing the two must be developed.
3. Most of the work presented is done in preparation
of radar observation by satellites.
4. Further investigation will be made:
a. to prepare the use of ERS-1 (1990) on oceanog
raphy, sea ice and soil monitoring
b. on the complementarity with visible and near in
frared. The satellites (Landsat, SPOT) will exist for
at least 10, 20 years.
5. Especially in microwave remote sensing methodology
seems to be well considered:
a. fundamental research can be conducted with instru
ments such as Dutscat (backscattering modelling)
b. interpretation can be undertaken with SAR (such as
VARAN-S). The quality and the number of instruments
must be increased and (inter-)calibration should be
obtained.
6. No specific and quantitative results were
presented on image and data processing. Preprocessing
or focusing is well handled by the payload
specialists.
