System-Testing Cinetheodolites 
by Stars”! 
EVERETT L. MERRITT, Photogrammetric Consultant, 
1411 Wade Place, Falls Church, Va. and 
Photogrammetric Engineer, Computation and Ballistics Division, 
U. S. Naval Proving Ground, Dahlgren, Virginia 
ABSTRACT: À new method of system-testing a Mk 5 cinetheodolite was 
initiated and completed at the Naval Proving Ground, Dahlgren, Vir- 
ginia, during the period August-October, 1955. 
The method is based on the photogrammetric reduction of data ob- 
lained from star exposures made at regular angular intervals, at known 
chronomeler times, and at a known geographic position. Mechanical 
precision of the rotation axes and the accuracy of direction angles are 
determined with these data. 
The vertical errors are determined from exposures made at regular 
intervals in a vertical plane having a fixed azimuth, while horizontal 
errors are delermined from exposures made at regular intervals in azi- 
muth having a fixed vertical angle. 
The results obtained are given at the end of the report. These data, 
because of the errors of timing, are considered correct to plus-or-minus 3 
seconds of arc. The errors of timing shall be reduced to plus-or-minus 0.2 
seconds of arc in subsequent tests. 
It is concluded from the results of the lest that the Mk 5 is a satis- 
factory ballistic cinelheodolite, except for an apparent camera-tube- 
bending effect on elevation readings, and that the method of lesting pro- 
vides a reliable knowledge of the instrument's static errors. 
SYNOPSIS 
HE cinetheodolite is a particular type of goniometric camera adapted to re- 
T phenomena in motion automatically. À goniometric camera is one 
that is capable of rotation about two mutually orthogonal axes that are equipped 
with graduated circles, whereby the direction angles of an exposure may be 
visually read or photographed. 
The space coordinates of an object may be determined with the camera 
coordinates of the conjugate images, the direction angles of the camera optical 
axes, and the ground coordinates of the two corresponding camera stations 
from which the object has been simultaneously photographed. The accuracy of 
the space coordinates so obtained depends on the accuracy of the given data. 
Of particular interest here is the accuracy of the goniometric and camera data, 
or specifically, the given mechanical direction angles and the camera coordinates 
(x, y, f) of an image. 
The accuracy of the direction angles is dependent on: 
(1) The mechanical precision of the goniometric axes (horizontal and vertical 
axes). 
* Statements and opinions advanced in this paper are to be understood as individual expres- 
sions of the author and not necessarily those of the Navy Department. 
T This is one of the papers obtained by the U. S. Reporter for Commission V of the Interna- 
tional Society of Photogrammetry. 
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