Survey Strategic Context – final paper

LINZ and the New Zealand Institute of Surveyors (NZIS) have completed a joint study on the likely future of the cadastral survey industry and what can be done together to move forward.

"The Survey Strategic Context project balanced conceptual ideas about the future with a practical view on what we could action to improve the sector," says Surveyor-General Don Grant. "We've ended up with a useful view of the future that incorporates both public and private sector ideas, as well as benefits for land owners. This gives us a good framework for decision making as we move forward."

The view that has been developed is based on principles that support the discovery, access, assessment and application of an increasing range of cadastral information that defines the rights and privileges associated with land.

The cadastral surveying industry of tomorrow will meet a wider client base with differing demands involved in a range of activities such as:

• tenure decisions
• land development
• administration and management, and
• wider uses such as research, policy work or marketing.

At a practical level, the study recommends what challenges, strategic objectives, guiding principles and contributing actions should be addressed by LINZ and NZIS as we develop the sector together.

"The real benefit of the study has been the interaction between LINZ and NZIS, and the co-operation that will be required to work through the recommendations to overcome the challenges in the up and coming years," says Bruce Manners, NZIS past president and study group member. "That will require both joint and independent work, and the LINZ/NZIS partnership formed during the study gives a good basis for moving forward."

Read the final paper, The Future (PDF 464KB), and find out more about the Survey Strategic Context including documents, news, background and process.

Offline Plan Generation update

The development of Offline Plan Generation (OPG) is progressing well.

As advised in the September Landwrap, Release 3.3 included new Landonline functionality to support the export and import of data to and from OPG. This functionality will be activated when OPG is launched late June/early July 2010.

A comprehensive testing programme will be completed prior to the launch. This will allow a representative group of e-survey users to conduct pilot testing.

This timing will also allow e-survey users a few weeks to become familiar with using Landonline under the new Rules for Cadastral Survey 2010. The new Rules are due to come into effect late May next year as of part Release 3.4.

For a refresher on the high level design of OPG, see article Plan Generation – project update in the September 2008 edition of Landwrap.

Replacing geodetic marks

A geodetic mark is sometimes renewed or reinstated in the course of carrying out a cadastral survey. Where this occurs, it is important that Item 19: Survey System Maintenance in the Survey Report is completed by surveyors. This enables the geodetic database to be updated with the new mark information.

Many geodetic marks have ellipsoidal and/or normal orthometric height information. In this situation, the information in the Survey Report needs to clearly state whether the replacement mark is in the same vertical position (within 3mm) as the original mark.

If the mark is not in the same vertical position, the geodetic database will be updated by LINZ with this information so that future surveyors do not rely on the height.

Impact of Fiordland earthquake on NZGD2000 - update

In the July edition of Landwrap, we discussed the Fiordland earthquake that occurred on 15 July 2009 and its impact on the geodetic system. Since then, further fieldwork and analysis has been carried out to better understand the earthquake and its effects.

In August, a team of LINZ and GNS Science surveyors re-surveyed 27 marks throughout Southland. These marks had previously been observed as part of a GNS Science deformation monitoring campaign, so had accurate pre-earthquake coordinates. At each site, 48 hours of GPS data was collected and processed to produce post-earthquake coordinates accurate to a few millimetres. GNS Science used this data to produce a model of movements as a result of the earthquake.

LINZ is in the process of incorporating this local model into the National Deformation Model (NDM), which is a core component of New Zealand Geodetic Datum 2000 (NZGD2000). This will enable pre-earthquake and post-earthquake data to be seamlessly combined.

Impact on accuracy

Research has been carried out to determine the impact of the earthquake on the absolute accuracy of coordinates of geodetic marks.

As expected, the number of marks failing the accuracy standard decreases with distance from the earthquake's epicentre (Dusky Sound in south-west Fiordland).

The table below details the proportion of geodetic marks in the affected area failing the standard after the earthquake.

Order	Pass	Fail	Total	% Fail
2	25	3	28	11
3	256	16	272	6
4	480	0	480	0
5	2393	265	2658	10

The vast majority of geodetic marks continue to comply with the accuracy standard. For this reason, there are no plans to downgrade the orders of any geodetic marks. Once the updated deformation model is available in early 2010, those marks that are currently failing will become compliant.

Relative accuracy over short distances (a few kilometres) has not been affected by the earthquake. Therefore, most surveys will not have any problem combining post-earthquake measurements with pre-earthquake data, even without the updated deformation model. Conflicts will only arise where the survey covers a large area, such as a large geodetic survey.

Results are in for geodetic questionnaire

The results are in for the geodetic online services questionnaire, which ran on the LINZ website from July to October 2009.

The questionnaire's purpose was to determine who is using online geodetic services and tools and why, which tools are being used, what customers think of the current services, and how they can be improved.

"We had a great response with 318 people taking part," says Graeme Blick, LINZ's national geodesist. Respondents came from a diverse range of backgrounds including land surveying professionals, crown research institutes, local authorities, and utility and civil engineering companies.

Unsurprisingly, the questionnaire results told us that 94% of the online geodetic tools are being used for professional purposes, with the remaining 6% for recreation.

"As the results are being analysed, some interesting themes are emerging, most notably around the PositioNZ network," says Graeme. "It's quite clear that many people have little or no knowledge about it, what it can be used for, and how to use it. My team will be working with the Customers team to think about ways in which we can better market PositionNZ, and help people use it more."

Analysis of the results is continuing after which decisions will be made on how best to put some of the suggested improvements into action.

The questionnaire results are available on the LINZ website.

New e-survey tip and hint

The e-survey Tips and Hints on the Landonline website are continually being refined and added to.

Survey sheets on Computed easement plans

As Landonline has a requirement of linking to a minimum of two existing marks in a Computed easement plan, often a surveyor is required to capture additional traverse lines to enable this linking.

The capture of these traverse lines will then create a System Generated Traverse Diagram (SGTD) and Survey Sheet by default.

As a Survey Sheet is not a requirement of a Computed plan, the surveyor can choose whether to use the Survey Sheet created or alternatively, remove the SGTD from the Survey Sheet, which will then create only Title sheets.

To remove the SGTD:

• Open layout sheets
• Select Survey Sheet radio button
• Highlight the diagram laid out on the Survey Sheet
• Click on the left arrow to remove the diagram
  
  

This will leave the Survey Sheet blank and it will not be generated.

• Select 'Complete' button to generate new images

When plan compilation images are generated there will be no Survey Sheet attached.

Are you using the e-survey best practice tools and tips?

Spanning a wide range of topics, the best practice section includes the tips and hints full index.

The e-survey training resources section has all the links and background on training materials provided by LINZ such as the user guide, computer based training (CBT) DVD, and the support available to surveyors.