Module 1.2: Data Quality

Here we are in week three module 2 of special Topics in Geographic science. This week's module was continuing on from last week of data Quality- Standards. Some of the learning outcomes from this week's module included learning how to determine the quality of road networks, determining the positional accuracy of the two road networks by comparison and understanding and employing the methodology of procedures provided by the National Standard for Spatial Dara Accuracy (NSSDA).

We were tasked with determining the positional accuracy of road network according to standard methods. Determining the accuracy estimate using two sets of street data provided to us from the city and from StreetMap USA. We were tasked with following the procedures in the Positional Accuracy Handbook. Starting off with determining horizontal accuracy then creating three data set where I selected 20 appropriate test points. One of the data sets using the orthophotos as the reference data for the test points. Then adding the X and Y coordinates for all the test and reference points. Then using a table to calculate my accuracy stastics ending with a report of my accuracy statement.

Here below is a screen capture of the locations of my test points.

According to NSSDA guidelines, horizontal accuracy at the 95% confidence level is expressed as:

 Test data meets horizontal accuracy of 141.37 feet at 95% confidence for the ABQ.

 Test data meets horizontal accuracy of 15,754.62 feet at 95% confidence for the StreeMap.

 This to me showing the ABQ layer to be more accurate.