Water Crossin Surveys at a New Level

摘要

When establishing heights on large geodetic networks, the main problem surveyors encounter are wide bodies of water, such as rivers, that need to be crossed without losing accuracy. Thanks to special procedures these kinds of crossings have been successfully done in the past using levelling instruments and total stations, but seldom at a first order level when distances exceed one kilometre. Combining conventional instruments with digital camera's and image processing now brings transferral of heights with first order accuracy within reach, even with sighting distances of over one kilometre.