Improving Field Efficiency of Cadastral Surveyors

My premise is that greater satellite numbers can dramatically improve field efficiency. Cadastral surveyors typically have a common procedure for minimising the chances of bad GNSS fixes by measuring a survey mark twice. The 2 fixes are typically separated by at least 1 hour to ensure that the GNSS geometry has changed.

By leveraging off the 4 GNSS constellations in orbit, it is possible to remove the need for the second occupation. If the need for a second occupation is removed, the speed and therefore the efficiency of a field survey team can be increased by almost double.

The process is to observe at each survey mark twice, but only visit once. The first occupation uses 2 of the GNSS constellations (GPS & BeiDou for example) and then a reoccupation is done immediately afterwards  using the other 2 constellations (Glonass and Galileo).

As these 2 occupations are independent of each other (different satellites in different locations) they provide the same level of check as a repeat visit provides. The other benefit from using this method is that it is possible to compare the 2 occupations before leaving the mark to ensure that they agree within the tolerances expected.

Read our paper on the testing of this concept:

Open for discussion, let me know your thoughts on multi-constellation GNSS cadastral survey.

Bruce Robinson – Director, Global Survey – bruce@globalsurvey.co.nz or on LinkedIn