Q&As on Geodetic Control & the Rules for Cadastral Survey 2010
These questions and answers relate to geodetic control and the new Rules for Cadastral Survey 2010. They were formed during a series of education seminars on the new Rules held around the country in September 2009.
Other questions and answers on the new Rules are also available.
If you have a question, please email newcadastralrules@linz.govt.nz.
- With more use of GPS, is LINZ going to drop trig beacon maintenance?
- No. Our intention is to continue to support the use of traditional survey methods.
- Is LINZ going to do more control network upgrades in tricky areas in Central Otago?
- There is an annual Geodetic Control Programme and a process in place for surveyors to submit information on areas for consideration for that programme.
- Is LINZ going to do more NZGD2000 updates?
- LINZ will continue to update NZGD2000 to enhance its spatial accuracy and include additional NZGD2000 marks.
- Should control marks connected to, but a long way from, the parcel under survey (eg a GPS base station or a one way ray observed to a trig) be included in the CSD?
- These long vectors can make the spatial network in Landonline difficult to interpret, particularly in the vicinity of the base station or trig that could have hundreds of connected vectors. Another problem with including these distant marks in the CSD is their effect when the survey is later searched for – the resultant information is at a scale that is of little interest to the user and makes the survey difficult to view and interpret.
It is noted that in the case of a GPS base station, the information is effectively to enable errors to be corrected in the GPS receiver. In the case of the one way trig observations; the rays are one of many checks and balances carried out by the surveyor. Both types of connections are often subsidiary to the survey.
It is therefore recommended that unless these vectors or observations are essential to ascertain or verify a position, or to satisfy the requirement to connect to the control network, that this information is only noted in the survey report or could be included with field notes and calculation data.
