2-11. Navigation Satellite Timing and Ranging Global Positioning System. The NAVSTAR GPS is
capable of determining accurate positional, velocity, and timing information. The PPS consists of
military users and authorized representatives. A PPS user can obtain high-accuracy instantaneous
positioning if the receiver is capable of accepting the necessary cryptologic variables. When two or
more receivers are used, it is known as DGPS surveying. The error values are determined and removed
from the survey either by real time or postprocessing of the data. The type of DGPS survey used is
dependent on accuracy requirements. There are two basic types of DGPS surveys--static and dynamic.
a. Static surveying uses a stationary network of receivers that collect simultaneous observations
over a predetermined time interval. They yield the best accuracy.
b. Dynamic surveying uses one stationary receiver and any number of remote or roving receivers.
It allows for rapid movement and collection of data over a large area. When operating in a real-time
mode, the roving receiver provides very accurate positions almost instantaneously on the battlefield.
2-12. Computer Information Systems. Surveying has become a digital science. Modern survey
systems work with software specifically designed to process field data, perform computations, and
produce a precise product, whether it be a GPS network, a digital database, or computer-aided design
(CAD) and computer-aided design and drafting (CADD). GPS-S computations require a computer
system to process large amounts of mathematic variables. Efforts should be ongoing to obtain or
upgrade to the fastest system available. Computer resources are standardized throughout TOE units
with topographic surveyors. Application (such as databases or word processing) and functional (such as
adjustment or CAD) software packages have increased the efficiency and productivity of topographic
surveyors. The SIC collects and disseminates the positioning and orientation requirements of NIMA,
FA, ADA, USAF, and armor units and maintains a digital database capable of archiving, querying, and
manipulating survey control. Topographic surveyors are equipped with common GPS hardware and
software and CAD and survey-application software.
PART H - FIELDWORK
2-13. General. Topographic surveyors perform most of their operational duties away from the parent
unit, in constantly changing conditions. Survey fieldwork consists of making observations and
measurements over a project area or battlefield; recording data; and returning the data to the computer or
draftsman for computation, compilation, and dissemination.
2-14. Weather and Terrain. Weather and terrain can adversely affect field surveys. The effectiveness
of optical and electro-optical instruments can be severely reduced by fog, mist, smog, or ground haze.
Swamps and flood plains under high
2-9
EN0593
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