al 
Video Tape Recording: 
Quite a lot of work has gone into converting the AGA 
Thermovision signals into TV compatible waveforms, and 
it is possible to record directly onto tape electro 
But chiefly due to the 4-field interlace format, 
playback must be done through the Thermovision display - 
not standard TV monitors. We chose the pragmatic approach 
of simply picking up the Thermovision imagery with a 
small black-and-white TV camera, together with the 
visible terrain optically superimposed, virtually imaged 
at the distance of the terrain features being examined. 
The raster sweeep inconsistancies between the Thermo- 
vision and the CCTV systems, it turned out, are practically 
undetectable on the TV monitor, in realtime as well as 
playback. 
One thing is still lacking: the 'colour dimension' which is 
lost through the use of the small black-and-white camera. 
Smaller colour CCTV cameras which will fit the top of the 
Superviewer (and not collide with the roof OF the heli- 
copter) are anticipated before the end of 1978. This 
will be the final 'breakthrough'. For the present, the 
slight flicker which can be noticed in the thermal 
imagery is helpful in separating it from the visible 
light imagery on the TV monitor screen. Simultaneous 
soundtrack recording of the cabin-intercom crew conver- 
sation also aids in identifying what is happening on the 
video tape during ground playback. 
Photorecording on Colour Film: 
The natural colours in the hybrid view make it a simple 
matter for the instrument operator to follow terrain 
features while studying the thermal pattern distribu- 
tion. Exact locations of thermal anomalies, hot or cold 
relative to the surrounding terrain, generally appear 
as abstract forms or spots, unrecognizable by themselves 
on the Thermovision screen. By superimposing them on a 
background of natural colours visible through the Super- 
viewer, recognition is often automatic. Registering the 
same view on colour film was a primary object of the 
development, for use in instructing new operators. 
The advent of fast negative colour film (Kodacolor 400) 
with ASA 400/DIN 27 exposure index, at the time of our 
initial flight-photography trials over forest fires in 
North America (the summer of 1977) must be attributed 
to our success - right from the beginning. That, and the 
appearance of a new 35 mm SLR camera with automatic 
aperture exposure control (Canon AE-1). The automatic 
aperture was a great advantage, since the instrument 
operator's hands are full, preventing a check of critical 
exposure parameters during fast flybys at low altitudes 
over patrol objectives.