I5PR5 
UNISPACE III - ISPRS/EARSeL Workshop on 
“Remote Sensing for the Detection, Monitoring 
and Mitigation of Natural Disasters” 
2:30-5:30 pm, 22 July 1999, VIC Room B 
Vienna, Austria 
NATURAL DISASTERS 
REMOTE SENSING CAPABILITIES AND APPLICATIONS IN A WIDE CONTEXT 
P. Gudmandsen 
Technical University of Denmark 
DK-2800 Lyngby 
KEY WORDS: Natural disasters, remote sensing, visual/infrared systems, active microwaves, passive microwaves, flood monitoring 
system. 
ABSTRACT 
A review is presented of remote sensing techniques that have proved useful for monitoring natural disasters. It includes visual and in 
frared systems, active microwave systems such as SLAR, SAR and InSAR and passive microw r ave radiometer systems applied from 
aircraft and satellite. The capabilities of these systems are considered as well as their limitations in tire context of monitoring various 
natural disasters: floods, landslides, oil spills on the ocean, forest fires and desertification. Availability of data from aircraft and satel 
lite for these purposes is considered. Thoughts are presented as to an integrated system for flood management including various aspects 
related to responsible authorities that might take advantage of remote sensing techniques. 
INTRODUCTION 
This paper presents considerations as to the application of re 
mote sensing data from aircraft and satellite to assist authorities 
(end users) responsible for management of natural disasters. In 
this context remote sensing is regarded a tool which has a num 
ber of capabilities but also some limitations. The paper gives a 
review of these - perhaps with emphasis of the limitations in 
order not to be accused of over-selling the techniques (which has 
happened so often before). However, at the outset, it shall be 
stated clearly that remote sensing is a useful tool as lias been 
demonstrated in many papers and workshops and conference 
presentations describing cases of natural disasters. 
The paper deals first with the commonalties i.e. operational as 
pects of aircraft and satellite systems, followed by cliapters on 
sensors wliich have proven useful for monitoring natural disas 
ters with emphasis on microwave systems. In tliis connection 
applications of data for different categories of disasters are dis 
cussed. Since tliis paper is followed by a number of presentations 
of applications I have refrained from including images describing 
the points raised. 
DATA ACQUISITION 
In all cases of natural disasters timely availability of data is a 
must and will in most cases involve remote sensing data. There 
are two ways of acquisition - by aircraft and satellite - which I 
shall consider briefly in the subsequent sections. 
Aircraft data 
Aircraft carrying suitable sensors and instruments have proved 
very' useful in the past and is in some cases the only useful 
proposition due to the fine spatial resolution that may be ob 
tained from the relative low altitude. The aircraft may be directed 
to the disaster areas with great position accuracy due to modem 
navigation techniques. 
Timely availability of data to responsible authorities is, however 
dependent upon a number of pre-requisites such as 
(a) availability of a dedicated aircraft equipped for the pur 
pose, that may be operational by a well-trained crew at short 
notice 
(b) a suitable means of recording the data acquired so that they' 
may be easily introduced into the analysis system of the end user 
- a geographical information system, for instance - that has been 
implemented for the purpose 
(c) a way of transferring data to the analysis centre eventually by 
aircraft-to-ground communications to reduce delay. 
A trade-off between the processing onboard and on the ground 
has to be found. It might be of advantage to have the data trans 
ferred in a final format that includes acquired navigation data. 
(d) flight tracks may be designed so that parameters such as an 
gle of incidence and view angle may be varied over the area 
which is useful for the data analysis. 
It shall be recalled that an aircraft may not be operational under 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXII Part 7C2, UNISPACE III, Vienna. 1999 
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