84
II) Straight lines and linear graduationsfor special metric tests
(e.g. tracking error, backlash, straightness of the ways,
spindle errors.
III) Targets for the optical resolution tests or targets with a
sinusoidal frequency distribution of density,
IV) Pseudo-sinusoidal curves for the dynamic tests.
V) Special targets for the testing of automatic stereo-correlation
systems, etc.
b) Auxiliary devices are used as measuring or as reference
units mainly in differential tests. They apply to some metric or
physical requirements as, for example, horizontality, verticality,
perpendicularity, parallelism, straightness, plainness, intersec
tion of axes, optimum illumination, constant temperature, etc.
The corresponding auxiliary devices arelevels, auto-collimators,
micrometer dials, thermometers, light meters, auxiliary eye
pieces (with or without a measuring mark), special electronic
and other equipment. The auxiliary equipment should be ac
curately calibrated.
The auxiliary devices are normally used for laboratory tests,
with a few exceptions (e.g. Santoni instruments, C8 Stereoplani-
graph,
Regarding the mode of restitution we distinguish between the
stationary restitution (called also static) and the dynamic restitu
tion. Any kind of photogrammetric restitution can be classified
in one of the two mentioned categories.
a) In the stationary mode of restitution the output is recorded
only when the tracking unit is stationary. Recording can be realised
differently
I) point by pointin numerical or graphical restitution,
II) section by sectionin rectification by zones or facetts,
III) the whole photograph simultaneouslyin perspective or
affine rectification.
b) In the dynamic mode of restitution, the output is recorded
continuously during tracking. The operations belonging to the
dynamic mode of restitution are the following:
I) plotting (or scribing) of planimetry, contour lines, profiles,
drop-lines.
II) photo-printing of orthophotographs, contour-lines, drop-
lines.
So far, dynamic tests have only been developed for the plotting
of planimetry.
In practice, the different aspects of tests discussed occur in
various combinations. However, not every combination is expe
dient or possible.
The routine tests are usually comparative integral tests, using grid
