The second session I attended at the Where 2.0 Conference after the Thursday morning Keynote addresses was a talk entitled “The Use of Light Detextion and Ranging (LIDAR) for Collecting Map Data”. The talk was given by Jeff Raimo and Jessica Borak of Navteq. Navteq is a provider of global navigation data.
The pair explained the three components that make up the mapping platform mounted on the Navteq vehicles. The first is a 360 degree mobile laser scanner. I recognized it as the kind of mobile laser scanner sold by Topcon. (Other surveying equipment vendors sell similar products, and my company has an instrument that uses a similar technology. However, our scanner is the more precise “non-mobile” type that is placed on a traditional surveying tripod and operated by qualified land surveying technicians.) The second component is high resolution panormaic cameras. The third component is positioning sensors, such as GPS, gyros, and IMUs.
Navteq has 19 of the mapping vehicles using the mapping platform I just described on the road currently. They will have 23 on the road by the end of the year. In three to four years they will have LIDAR mapping for all the major metro areas and major road corridor's in the United States.
This massive LIDAR data set will be made available to application developers through an API that has yet to be released. This will allow, in theory, GIS users to perform feature extraction from the data from the comfort of there own computer, via the API. Responses to my questions confirmed the mapping platform was using commercially available surveying equipment, and that high-quality RTK GPS or traditionally established surveying control was not being used to determine the position of the point clouds collected with the LIDAR mapping platform. As is typically the case, little discussion was given to the techniques used to process and clean the data, or to its overall quality and accuracy.
I believe land surveyors and other geospatial professionals should be aware of the impacts this mobile scanning technology will have, while data consumers need to get over the “wow factor” quickly and start asking tough questions about data quality so they can determine what these point clouds can actually be used for. There will be numerous applications, but the data won't be good enough for some things people will try to use it for.
The Sunburned Surveyor