surveying iii (topographic and geodetic surveys) - Modern Prepper

water can impede leveling operations. Signals from the GPS constellation generally require a clear lineof sight to the sky. Urban and forested areas can mask or deflect the direct signal needed for accuratemeasurements. Good reconnaissance and proper planning can alert the field parties of the best times andmethods to use.2-15. Personnel. The rate of survey progress often varies in direct proportion to the training andexperience level of the assigned personnel. The most effective method for training personnel is underreal training conditions.2-16. Equipment. Equipment reliability must be considered when establishing completion dates.Modern, well-maintained equipment can often increase the rate of progress. Older equipment, ifproperly maintained or adjusted, will yield accurate results. Having to stop to repair or replace brokeninstruments or parts can result in a slowdown or halt a field survey. All equipment should be calibratedduring combat checks, before survey missions.2-17. Survey Purpose. The purpose and the type of survey determine the accuracy requirements, andthe accuracy requirements dictate both the equipment and the techniques used. For instance,comparatively rough techniques can be used for elevations in site surveys, but control-network levelingrequires much more precise and expensive equipment and extensive, time-consuming techniques. FirstorderGPS, triangulation, traverse, or leveling for the control networks must have high-accuracystandards; cuts and fills for highways are much lower. In some surveys, distances to inaccessible pointsmust be determined. High-accuracy distance and angle measurements are required so that these values,when used in trigonometric formulas, will yield acceptable results. This type of survey is directlydependent on the clearness of the atmosphere. Observing measurements for a single position can bedelayed for days while waiting on good weather.2-18. Errors. All measurements contain errors. Errors classified as systematic and accidental are themost common uncontrollable errors. Besides errors, measurements are susceptible to mistakes that arisefrom misunderstanding problems, poor judgment, confusion, or carelessness. The overall effect ofmistakes can be greatly reduced by following a preestablished systematic procedure. This procedure isadvantageous in all phases of a survey.2-19. Progress. Rates of progress vary, depending on personnel experience and repetition. As skill andconfidence increase, so will speed. Proper preparation and planning will reduce duplication of effort andincrease efficiency.2-20. Enemy. A hostile environment often forces a schedule adjustment. Night work requires greaterspeed, fewer lights, and increased security. Adding security forces increases the number of vehicles andpersonnel, which reduces efficiency and retards the time schedule.2-21. Observations of Distances and Directions. Topographic surveyors observe distances anddirections (angles) to establish the following:EN0593 2-10