In November of 2014, the American Society of Photogrammetry and Remote Sensing (ASPRS) published Edition 1 of the first ever mapping accuracy standards that are solely designed for today's digital geospatial data. Edition 2 was published on August 23, 2023 to correct some measures to suite today's technologies and processes and add six addenda on best practices and guidelines.
Motivation Behind the New Standard is:
Legacy map accuracy standards, such as the ASPRS 1990 standard and the National Map Accuracy Standards (NMAS) of 1947, are outdated (over 30 years since ASPRS 1990 was written).
Many of the data acquisition and mapping technologies that these standards were based on are no longer used.
More recent advances in mapping technologies can now produce better quality and higher accuracy geospatial products and maps.
Legacy map accuracy standards were designed to deal with plotted or drawn maps as the only medium to represent geospatial data.
Within the past two decades (during the transition period between the hardcopy and softcopy mapping environments), most standard measures for relating GSD and map scale to the final mapping accuracy were inherited from photogrammetric practices using scanned film.
New mapping processes and methodologies have become much more sophisticated with advances in technology and advances in our knowledge of mapping processes and mathematical modeling.
Mapping accuracy can no longer be associated with camera geometry and flying altitude alone (focal length, xp, yp, B/H ratio, etc.).
These factors can vary widely from project to project, depending on the sensor used and the specific methodology. For these reasons, existing accuracy measures based on map scale, film scale, GSD, c-factor and scanning resolution no longer apply to current geospatial mapping practices.
1) General Best Practices and Guidelines
2) Field Surveying of Ground Control and Checkpoints
3) Mapping with Photogrammetry
4) Mapping with Lidar
5) Mapping with UAS
6) Mapping with Oblique Imagery
Advantage of Specifying the New ASPRS Positional Accuracy Standards for Digital Geospatial Data for a Project
Users of the new standards do not have to specify accuracy details for the intermediate processes in products generation. The user needs to specify the final deliverable product accuracy and the new standards will set up all accuracy specifications for intermediate processes, such as ground survey, aerial triangulation, etc., involved in the production of the final product. Figure 5 illustrates such a concept.