and also the most convenient and most complete solution to
the sensor orientation problem. A high precision level of
orientation data will make such sensors directly acceptable
for high accuracy photogrammetric application. A particularly
interesting case will be laser profilers, or microwave scan-
ners, the effective use of which depends absolutely on direct
orientation data. Of course, interpolation principles may be
applied due to high correlation of orientation elements at
short time intervals.
It is not the place here to go deeper into such problems.
But it can be safely anticipated that the new navigation tech-
nology will have a great influence on the effective utilizati-
on of various sensors. It is quite likely that the conventio-
nal image of photogrammetry will change fundamentally in a
relatively short time. High precision navigation data will be
a prime element in the realisation of such trends.
7. CONCLUSION
This paper has reviewed the situation photogrammetry is faced
with in view of the progress in navigation systems. At pre-
sent such systems are emerging which will give camera orien-
tation data of very high relative precision. It is, at pre-
sent, not quite certain which precision level will be obtai-
ned. The optimistic expectations speak of camera positioning
accuracy in the order of 1! m, down to the dm range.Attitude
data are equally expected to reach angular precision in the
order of 10-5 ro 1075 (or 6 to 0.6 mgon). If such accuracies
are obtained by readily available equipment which is inex-
pensive enough to become standard for air Survey flight
mission the use of navigation data for orientation purposes
will fundamentally change photogrammetric working methods.
It has been shown - by simplified simulation - that the first
step of utilizing navigation data can consist in considering
them as auxiliary data for block-adjustment. The results in-
dicate that navigation data of moderate accuracy are already
highly effective in aerial triangulation greatly reducing
the required number of ground control points to the sole
function of establishing the reference coordinate system (and
possibly to establish drift corrections). Mapping at small
scales, medium scales and even large scales will be greatly
affected.
The second level of considerations regards the possibility
that navigation data are accurate enough to be used directly
for the orientation of photographs, avoiding aerial triangu-
lation partly or completely. In first instance photo-mapping
can be made more economic in this way. It remains to be seen
how soon the very high precision requirements will be met.
If the required level of precision will be reached 60 years
of indirect determination of orientation parameters in photo-
grammetry will be superseded and moved to a chapter in the
history of photogrammetry.
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