LINZ produces the Topo50 and Topo250 map series. The basis of those map series is a digital database containing over 6 million features. Existing features in the Topo50 database generally have a spatial accuracy suitable for a maximum scale of 1:50,000, as they were originally digitised from the paper topographic maps of the same scale. As both topographic data and Geographic Information Systems (GIS) have become more widely used in New Zealand, a higher level of spatial accuracy is increasingly becoming a requirement for users of the data. However, it would take considerable time and resource for the National Topographic Office (NTO) to improve the accuracy of the database manually due to the large volume of features that require adjustment and available resources.

In 2013 the NTO saw an opportunity to collect topographic data from external agencies, and to incorporate aspects of this data into the Topo50 database using automated and/or semi-automated processes. The reuse of more accurate and current data held by external agencies would enable the NTO to improve the Topo50 database more efficiently, benefiting users of the data.

Towards the end of 2013, a Data Collection Team was created as part of the NTO to develop processes for the collection, storage, and manipulation of external datasets. As you can appreciate, not just any data can be included and work is being down around data schemas, data differencing (change detection), conflation and other tasks.

Within the next year, LINZ will also look at how crowd sourcing geospatial data could aid in the data maintenance process. A recent visit to the USGS in Denver, Colorado, gave LINZ some insight on how and why they have implemented their very successful Volunteered Geographic Information (VGI) Program. As a result of this visit, LINZ sees good potential for crowd sourcing of topographic data. Will crowd sourcing data be the way forward for LINZ? Time will tell!