HOLMES & NaRVER, INC. JOB 640 PHOTO TOVER TRIANGULATION BRIEF SUMMARY OF iORK DONE Ae FPURFOE The enclosed computations are a tabulation of data obtained from a triangulation survey. This survey was requested for the purpose of confirming the positions of the photo towers constn:cted on Sites M, N, P & Q with respect to their "Zero Points", B. GENSRAL FEATURES Second-order triangulation was specified for fixing the positions of these towers. The base expansion figure was developed through station coral from base lines existing on Runit and Engebi Islands. The figure extends nerthward from Site M through Sites C, N, V, P, B&Q. All observations were made at night and a standard procedure was attempted throughout. oceupied, ith the exception of stations Elgin and Zero V all stations were On Sites N & Q traverse ties were mde to the adjacent photo towers not included in the basic figure. During the observing period som rain and considerable high wind was experienced. The weather conditions together with interference from constriction and scientific werk in the tower areas decidedly effected the results of this survey. >« COMPUTATION AND ADJUSTMENTS OF TRIANGULATION For the single chain of triangles shown for the basic figure (see page 1 of computations) the angle adjustment should have been made in two steps, (1) The station adjustment to make the sum of the angles around each point equal 360°, nd (2) the figure adjustment to make the sum of the three angles in each triangle :qual 180°, In precise triangulation the station adjustment and the figure djustmert are made in one opsration, by the methods involving the principal f least squares. The enclosed approximte method was used due to inconsistencies -l-