×

You are using an outdated browser that does not fully support the intranda viewer.
As a result, some pages may not be displayed correctly.

We recommend you use one of the following browsers:

Full text

Title
Papers for the international symposium Commission VI
Author
Sitek, Zbigniew

available, many of the project survey requirements would have been
met by them or their enlargements* We have to bear this in mind in
designing a production system for this series. We will revert to
this aspect after discussion of some other factors affecting time
required for prodcution.
'TIME FACTOR IN PRODUCING A MAP: PRODUCT SPECIFICATIONS:
MAP SUBSTITUTES
It was mentioned earlier that one of our major concerns is to
reduce the time taken to produce a map.
It is common knowledge that the stage of drafting (fairdrawing)
is costly as well as time consuming. It is here that map substitut
es like qrthophotomaps and rectified photos come out with flying
colours on two counts - reduced cost and reduced time. Misra (2)
strongly advocates the use of photomapping for developing countries,
the foremost reason is that this technique eliminates plotting and
reduces drafting work as shown in Fig. 2.
Aerial Photography
FIG.2. PRODUCTION OF 1:50,000/1:25,000 MAPS
CONCEPT OF STORED-CONTROLLED PHOTOGRAMMETRIC MODELS
Referring to diagram below we see that first field season (Octo
ber - April) and following recess (Office work) period (May - Sep
tember) are spent in field control work, computations and aerial
triangulation and the second field season in verification. Thus
conventional methods will take a minimum of two field seasons to
finish the job. This can be obviated by delinking the first field
n