Special Topics Week 2: Data Quality

For this week's lab, we tested the positional accuracy of two road networks in Albuquerque, New Mexico by digitizing well-defined points (in this case, road intersections) from imagery and comparing their coordinates to the coordinates of the intersections in these two networks. We followed the protocol of the National Standard for Spatial Data Accuracy to choose 20 test points (shown on the City of Albuquerque road network below, with quadrants to show the distribution of points), and then calculated the appropriate accuracy statistics, which are given below. 

 

Positional Accuracy for the City of Albuquerque road network: Tested 19.07529 feet horizontal accuracy at 95% confidence level.

Positional accuracy for StreetMap USA road network: Tested 181.3366 feet horizontal accuracy at 95% confidence level.

These data sets were tested according to the NSSDA.


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