Symposium on Remote Sensing for Resources Development and Environmental Management / Enschede / August 1986 
285 
A preliminary assessment of an airborne thermal video frame 
scanning system for environmental engineering surveys 
T.J.M.Kennie & C.D.Dale 
University of Surrey, Guildford, UK 
G.C.Stove 
ERSAC Ltd, Livingston, Scotland, UK 
ABSTRACT : Video based camera systems are being used by an increasing number of remote sensing users. These 
systems offer several adv-antages in terms of ease of use, speed of operation, portability and cost. Of 
particular interest are the thermal video frame scanning (TVFS) systems. These scanners, developed primarily 
for military purposes, differ considerably in design from the thermal infrared linescanning instruments 
traditionally used for thermal surveys in remote sensing. One specific example, the Barr end Stroud IR18, is 
described together with the modifications necessary to mount such a system in a number of light aircraft. 
Methods of digitally enhancing and classifying single frames of data are discussed. The paper concludes by 
considering the application of suitably processed imagery for environmental engineering projects such as heat 
loss monitoring, thermal mapping of roads, geotechnical site investigations and drainage, sewer collapse and 
utility duct surveys. Further potential areas of application are also identified. 
RESUW: Les utilisateurs de télé-détection utilisent de plus en plus l'appareil photographiaue oui se fonde 
sur le video. Ges systems offrent plusieurs advantages - facilité d'usage, vitesse d'operation, portabilité, 
et coût. Les systèmes qui se basent sur l'explorateur thermique de cadre video (TVSF) sont d'intérêt 
particulier. Le dessin de ces appareils explorateurs qui étaient dévéloppés pour les buts militaires d'abord 
différent considérablement des instruments d'exploration thermique et linéaire qu'on emploie d'habitude pour 
les levés thermiques dans le télé-détection. On décrit un exemple spécifique, le Barr et Stroud IR 18, et aussi 
les modifications nécessaires pour installer un tel système dans quelques avions légers. On discute les 
méthodes digitales de rehausser et classifier les cadres uniques de données. Le papier conclut de considérer 
l'application des images traités pour les projets de génie de l'environnement, par exemple, la surveillance de 
la perte de chaleur, la cartographie thermique de routes, les investigations géotechniques de site et la 
surface de captation des eaux, l'effondrement des égouts, et les levés des conduits utilitaires. On identifie 
aussi les autres domaines d'application potentiale. 
1 INTRODUCTION 
An increasing number of users in recent years have 
been considering the potential of video based aerial 
remote sensing systems. A wide variety of data 
acquisition systems are currently available and a 
selection of these are reported in section 2, 
together with some discusssion of the advantages of 
using video as a recording medium. 
One of the most exciting developments however, is 
in the use of thermal video frame scanners (TVFS) 
operated from light aircraft. The design features of 
such instruments, with particular reference to the 
Barr and Stroud IR18, are discussed in section 3. 
This is followed by details relating to the mounting 
of such a system in a variety of light aircraft. 
The use of digital image processsing techniques to 
filter and enhance single frames of thermal date is 
presented in section 4. The paper concludes by 
reporting some of the current projects for which the 
scanner has been used. 
2 AIRBORNE VIDEO BASED DATA ACQUISITION SYSTEMS 
A summary of previous literature which has reported 
on the use of video based data acquisition systems is 
given in Table 1. Several advantages can be cited to 
demonstrate the benefits of video based systems, 
which include system portability, near real time 
verification of data capture, rapid turnaround (since 
there is no processing stage), low cost of operation 
and ease of duplication of data (Meisner and 
Lindstrom, 1985). In view of these perceived 
advantages a research programme was initiated by the 
University of Surrey, in conjunction with the 
University of Glasgow, in August 1984 to evaluate the 
use of a portable TVFS system for remote sensing 
applications. Although low resolution thermal imaging 
Table 1 Summery of previous literature 
video based date acquisition systems 
airborne 
Spectral 
Region 
Author(s) 
Application 
(0.4-0.70um) 
Panchromatic 
(0.4-0.7ym) 
3 band colour 
(0.4-1.lpm) 
3 band 'false' 
colour 
(0.55-l.lym) 
4 band 
Multispectral 
(3-5.6u m, 
8-14pm) 
Thermal 
Infrared 
Mussekowski, 1983 Water 
assessment 
Vlcek, 1983 Forestry 
Vlcek and Cheung, 1983 " 
Meisner and 
Lindstrom, 1985 
Everitt Rangeland 
and Nixon, 1985 studies 
Nixon, Escobar and Vegetation 
Menges, 1985 studies 
Vlcek and King, 1984 Vegetation 
Vlcek, King and Vegetation 
Shemilt, 1984 Mapping 
Tice end Larsson, 1978 Heat loss 
Geraci and 
Celtebiano, 1983 
Geraci, 1983 
Clement, 1985 
Amin, 1986 
Oil pollutic 
Water qualit 
Water qualit 
Geothermal 
Mapping 
systems such as the Aga Thermovision have been used 
previously (Tice and Larsson, 1978, Geraci, 1983, and 
Geraci and Celtebiano, 1983) little attention has 
been focussed on the more expensive, but much higher 
performance, military forward looking infrared (FLIR) 
imaging systems.