1952 EXPANSION AND ADJUSTMENT
Reproduced from the-holdings of the National Archives
Pacific Southwest Region
Requirements for Operation Ivy resulted in the expansion of the
scheme to include the entire Atoll.
Some stations of the earlier
surveys had been destroyed and additional stations were required.
Fifteen stations were established, replaced or more precise values
determined.
AS the expansion permitted dosing the survey around
the Atoll to the Runit base line a check on tne previous work was
obtained.
The closing error of the survey before adjustment was
determined a8 approximately 1:25000.
An additional cheok was
obtained by inclusion of the zero line traverse in the Flora-Gene
area.
This indicated a closing error of approximately 1:70000
before ad justment of the adjacent quadrangle.
In order that the
values of a station would remain the same independent of the direction of computation through the net an adjustment has been
applied to the triangulation figures.
This consists of a side
equation adjustment which resulted in slight changes in the values
previously reported but of little consequence in computations made
to date.
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PLANE COORDINATE SYSTEM (IVY GRID)
A plane coordinate system has been established which is common to
all stations.
MThe origin of coordinates is a plane
through tri-
angulation Station Coral with assumed values of N 100,000.
100,000, at this station.
used as
East
A true meridian through this station was
the basis of bearings and was determined by computing through
the base expansion figure from the adopted azimuth of the Runit base
line.
Tne horizontal
control network
-3-
as
it now exists should meet