Highly accurate equipment and techniques and performed calculations based The location of new points by the measurementĬlassical (pre-GPS) geodetic surveyors measured angles and distances with Given that informationĪnd a beginning point whose coordinates are already known ('X,Y' on the high school pop quiz and 'latitudeĪnd longitude' at NGS), it is possible to build a framework to determine The remaining unknown lengths and angles of the triangle. Of the sides of a triangle, it is possible to calculate

Given a certain amount of information about the angles and lengths Those who remember their high school geometry course willįind the core of geodetic surveying familiar: This sketch illlustrates Point A to Point B by way of angles and a measured distance.ĭistances measured for scale are referred toĪs 'base lines.' Click image for larger view. You can browse through the instruments in the collection by clicking on the links to the right or click here to view the items in the Distance Measurement Tools Collection. Every surveying instrument reflects the brilliance, inventiveness, and sometimes pure determination, of the men who created and used them. It would be a mistake to think, however, that this is simply a series of pictures of pieces of equipment. However, throughout its history, NGS and its predecessor organizations have always maintained the same accuracy and precision required by the first Survey of the Coast Superintendent Ferdinand Hassler in the early 1800s.Īll of the instruments shown in the collection are the types and models used by the agency at one time or another. As the equipment evolved and became more sophisticated over time, the decrease in cost and increase in ease of taking distance measurements made the measurements more feasible. The collection traces the evolution of tools used to measure distances, from steel bars used in the 1800s to modern global positioning system (GPS) equipment used today.

Coast and Geodetic Survey (C&GS), the surveying arm of which was renamed the National Geodetic Survey (NGS) in 1970. This is a collection of 17 images that illustrate the history and development of the instruments and techniques used to make extremely accurate distance measurements by the U.

Altium measure distance