to meet project requirements, a substantially new and stronger scheme
Pacific Southwest Region
Reproduced from the-holdings of the National Archives
was necessary which could be expanded as required.
1949-50 HORIZONTAL CONTROL SURVEY
This survey was designed to meet the requirements of Operation
Greenhouse and adaptable to future expansion.
It consisted of
sixteen stations covering the Eastern portion of the Atoll from
Bogallua island to Eniwetok island and included five atations of
the previous surveys.
As it was determined that Station North Base
had been disturbed it was necessary to measure
Base #2-Runit to second order accuracy.
a new base line North
The network expanding from
this base line was executed to second order specifications and procedure of the U. S. Coast and Geodetic Survey.
The geographical
position of Station Runit and the agimuth of the line Runit-Coral,
as determined by the previous survey, were adopted as the origin of
position and agimuth.
1951 EXPANSION
An expansion of the survey was necessary to meet additional requirements which could not be
anticipated earlier.
Several additional
islands were located by local triangulation and photo tower and zero
locations were determined.
on all project islands.
Local control traverses were established
The accuracy of these controls depended on
their uses and were generally of third order.
The zero lines and
some traverses for location of instrumentation were established to
first order traverse specifications.
An independent plane coordinate grid was established at each of the
zero areas for location of instrumentation.
While satisfactory re-
Sults were obtained it brought out the desirability for an overall
Atoll grid.