(481)
1. Correction ^ bx of the base length: (for the formulae: see the French text)
z = mean z-distance of point Nx in the two models K-1, K
Az — difference of these two z-distances of point Nx (The models 1 and n
are furnished with control points).
2. Correction of the Y -tilt: (y/z is constant for all models).
3. Vertical base-component: H, and Hn + 1 are the altitudes of the air stations
2 and n4 1.
4. Altitude of air station K.
5. Horizontal base-component (swing): (^ x/— the difference of the abscisses
x' of the same point A or B in the two models).
6. Coordinates of point Ni. in the projector-system: Dx, Dy, D, — differences
of the coordinates of the points Ni: and Nx in model (k—1), corrected
for the systematic errors and for the local deformations of the models.
The final compensation over the control points is executed with the help of
the method of least squares.
In the antennae the terms, e, a, y are calculated, supposing
A bi — A bn =0, Ha 51 HE = 0, 2.8.0.
THE DETERMINATION AND CORRECTION OF ACCIDENTAL
LOCAL DEFORMATIONS OF PERSPECTIVE RAYS
by
Dr. G. Poivilliers.
(Complete French text is given on page (414)-47-1 of the General Report).
The theory of the plotting is based on the hypothesis of the identity of the
perspective rays of the photographic bundle with the bundle of lines through
the air station to the groundpoints.
The traversing is based on the hypothesis of the presency of only two kinds
of errors: errors with a systematic character descended from systematic defor-
mations of the perspective bundles and errors with an accidental character de-
scended from imperfections of sight to the points.
The hypotheses are not rigorous, sometimes local deformation in the per-
spective bundles are to be found, deformations descending from either defor-
mations of the emulsion base or from deviation of light-rays that have passed
zones of atmospheric turbulence.
These local deformations result in fractures that have been stated in the
repartition of the errors after the compensation of the traversings.
The communication treats a method of discrimination of those perspective
rays that are subject to such deviations; the errors resulting from these devia-
tions are eliminated.
The deviations have two components: the first is the transversal compo-
nent, that falsifies the transversal parallax and results in: 1. an error in the
execution of the relative orientation of the two perspective bundles of a model,
and 2. deformations in this stereoscopic model that propogate theirselves in all
following models. The second, the lateral component, modifies the stereoscopic
