50 
Symp 
would of course need a much denser field of control Trorey, L.G. 1947. 
points than 1 per 85 photos. In fact, each Slotted templet error. 
individual aerial photograph would need control. Photogrammetric Engineering, vol. 13, no 2, 
This independent control per photo is provided by p. 227-229 
the Landsat map control method in a more elegant 
way. 
New 
by us 
5.2 Evaluation 
The Landsat control method seems ideally suited to 
mapping situations in remote areas where only 
unreliable maps exist, and with aerial photographs 
which have been flown with tilts and altitude 
variation beyond normal margins. Usually, these 
three conditions are encountered simultaneously. 
In remote regions of the Amazon basin, for instance, 
reliable maps are hard to find and aerial photography 
coverage by local air survey companies is not 
exactly awe inspiring as far as quality is concerned. 
In such conditions it is going to be nearly impossible 
to employ the slotted templet method. 
In a mapping situation with ample ground control 
the slotted templet method would, as far as accuracy 
is concerned, win from the Landsat airphoto map 
control method. However, this situation is 
hypothetical because ample ground control implies 
that the mapping exercise must be taking place in 
the developed world where sophisticated 
aerotriangulation techniques have taken over. 
Therefore, the method of airphoto mapping using 
slotted templets has survived up to the present 
only in remote areas. Even here, the slotted 
temple method will have to give way to another 
approach. This could be with Landsat controlled 
airphoto mapping, because it has a number of 
advantages over the slotted templet method, 
especially with airphotos that were flown at 
varying altitudes and with tilt. These advantages 
are the following: 
* photo tilt and scale variations do not influence 
accuracy of the map; 
* no ground control is required prior to flying; 
* Landsat control is always densely and evenly 
distributed over the map which implies that 
acceptable accuracy also is evenly distributed; 
* map compilation is done very swiftly even under 
field conditions. 
We can therefore conclude that the slotted 
templet method has become obsolete, not only in 
the industrialized world but also in mapping 
situations at the 'last frontiers'. Especially in 
the latter regions the airphoto map control method 
using Landsat is the preferred alternative as it 
is the most cost-effective mapping routine for the 
production of basemaps with an mean accuracy 
requirement of 30 m, and as it can always be used 
in conjunction with topographical traversing work 
to correliate field data with airphotos and to 
update basemap accuracy. 
REFERENCES 
Dovey, S. 1983. 
Improved framing accuracy with Landsat-4, ALS 
Newsletter, vol 3, no. 1, p. 5-6. 
Dovey, S. 1986. 
Personal communication. 
Slama, C.C., H. Ebner and L. Fritz. 1980. 
Aerotriangulation, in: 
Manual of photogrammetry (ed. C.C. Slama), 
p. 453-456. 
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