In our previous Newsletter we talked about Horizontal Accuracy Reporting and the new standards put forth by the American Society for Photogrammetry and Remote Sensing (ASPRS), Positional Accuracy Standards for Digital Geospatial Data, in November 2014. The updated standards were designed to tie together past experience with current industry practices for preparing data. The new standard provides guidelines for calculating both the vertical and the horizontal accuracy and focus on the higher level of accuracy that are currently available using the latest technology.
A section of the updated 2014 ASPRS Standards addresses horizontal accuracy. Horizontal accuracy requires a known position (an identifiable marker) that is clearly defined within the data itself. In order to determine horizontal accuracy for any data type, surveyed control needs to be collected in a manner to be visible within the provided dataset. Visible control could include: a large road arrow (Figure 1), painted cross walk lines (Figure 2) or any other identifiable and easily measured feature.