Landsat contained more information than the 
human eye can discern on the photographic 
procucts. Computer methods will also prove 
faster. 
Dr. G. Hildebrandt (F.R.G.) emphasized that three 
sources of trouble occurred in vegetation inter- 
pretation: 1) phenological causes, 2) effects of 
varying slopes and aspects on shadow effects, 
and 3) different spectral responses due to varying 
illumination across the scene. Mr. Heller felt that 
the effect of these sources of variation had been 
well established from spectral radiometric and 
phenology studies and other experience. More 
work is required to account for these effects in 
visible interpretation work. 
Dr. S. Schneider (F.R.G.) asked Mr. Speight if the 
system of land classification was based only on 
morphological characteristics. He replied that 
the analysis was based mainly on morphological 
characteristics, but vegetation attributes, espe- 
cially the forest, were included. Some fifty or 
sixty attributes describing the forest based on 
species composition, average height and density 
were used. Dr. Schneider asked Dr. Girard if 
carrying out photographic flights at different 
seasons was important in order to cope with 
the effects of vegetation when classifying soils. 
He replied affirmatively and added that the timing 
of flights also depended on what application 
was to be made of the soils information. 
Mr. J. Colcord (U.S.A.) recommended: 1) complete 
calibration (x, y, z, and v ) to remove some un- 
knowns, 2) use of stereo orthophoto maps for 
recording original interpretation data, and 3) 
questioning the use of "non-metric" small-format 
cameras. To the first and last remarks, Dr. Baker 
felt that the degree of precision or accuracy 
depends greatly on user requirements and the 
kind of data collected, especially qualitative 
versus quantitative data. In relation to the second 
question, it was pointed out that an excellent 
example of a stereo orthophoto map produced 
by Mr. Kalensky (Canada) had been demonstrated 
at the Congress. 
Dr. U. Wolf (Italy) asked Dr. Girard about the im- 
portance of vegetation when using thermal in- 
frared imagery to interpret soil conditions. He 
replied that vegetation was very important in the 
interpretation of soil conditions and that the 
selection of the correct time of day for collecting 
the imagery was important. 
Friday, July 16, 1976, from 14.00 to 16.30 
Session 4 of Commission VII 
Topic: Special Session 1 
Chairman: Dr. L. Sayn-Wittgenstein (Canada) 
General Discussion 
Dr. P. Fagundes (Brazil) continued with the Work- 
ing Group Report: "Natural Resources Inventory 
(Amazon Radar)" WGR VII/02. The Radar Pro- 
ject was described as being extended beyond 
the Amazon Basin and has been renamed Radar 
Brazil. The progress made was outlined and the 
practical problems with high transportation 
costs, accidents and disease were covered. The 
mapping program is far advanced and many 
128 
maps, reports and statistics have been published. 
Radar imagery, combined with Landsat data and 
aerial photography has proved most valuable. 
It has allowed the mapping of areas which could 
not be photographed because of weather; it has 
indicated topographic relief not recorded on 
photographs and has thus pointed the way to 
geologic structures associated with commercially 
interesting mineral deposits. 
The discussion dealt with sampling accuracy, 
which is still being evaluated and a question 
from Mr. R. Heller (U.S.A.) concerning the forest 
classification used. Broad classes are recognized 
and illustrated by keys. Dr. H. Rib (U.S.A.) en- 
quired about the control system used. In the 
absence of known ground stations a Shoran 
system and coordinates provided by satellite 
transmission were used. 
Dr. V. Dehai Kulkarni (India) and Mr. G. Farhoudi 
(Iran) presented their papers "The Significance 
of an ARC Shaped Dark Patch on the Nimbus 
II! (HRIR) Imagery of India" PP VII/22 and "Nutz- 
ung des durch Abdeckung eines Auges entste- 
henden ráumlichen Effekts zur Betrachtung von 
Einzelbildern bei Photointerpretationen" PP VII/ 
14, respectively. Mr. B. Sorensen (Italy) described 
the use of Landsat data, color infrared film and 
other sensors for water studies. This led to a 
discussion of the effects on scanner data of the 
exhaust of aircraft and in particular of the dis- 
turbance of the atmosphere by the propeller 
blades of helicopters; serious disturbances 
appear to be involved in the latter case. The 
session concluded with a presentation by Mr. F. 
Hilwig (Netherlands) in which he explained how 
one should approach the problem of selecting 
imagery, what agencies are involved, what data 
are available and what other inputs (crop calen- 
dars, phenological and meteorological data) 
should be considered. 
Monday, July 19, 1976, from 9.00 to 10.30 
Session 5 of Commission VII 
Topic: Environmental Monitoring 
Chairman: Dr. S. Schneider (F.R.G.) 
Dr. Schneider introduced the topic of the session 
by observing that two kinds of monitoring could 
be identified; one related to following the pro- 
gress of natural processes and the second 
treating man's influence. The latter is sometimes 
referred to as surveillance. 
Working Group Report 
Authors: Dr. A. Aldred (Canada) 
Dr. L. Sayn-Wittgenstein (Canada) 
Title: Environmental Monitoring: Role of 
Remote Sensing WGR VII/03 
Some definitions and concepts related to envi- 
ronmental monitoring were discussed and 
examples of the role of remote sensing were 
drawn from such disciplines as agriculture, 
forestry, wildlife studies, ice reconnaissance, 
shorelines, air pollution and disaster monitoring. 
The concept of using a network of permanently 
established sample points for environmental 
monitoring was described and illustrated. 
iud