Precision location analysis dialog box

• Use selected items only: select if you only want to include the items that you currently have the check-box selected for on the Geo-loc data and RTT data tabs. You may have used either these tabs or the map to select them.

• Use all items in the map boundary: select if you want to include all the items displayed within the map boundary.

This setting is mandatory. Enter a name for your analysis report. When this analysis is run this report name is then displayed on the Analysis results view's Case analyses tab.

The precision location analysis breaks down the area into 100 meter bins. It calculates the total number of RTT arc and GPS ping intersections, and the number in each bin. You can choose two types of calculations for displaying your analysis:

• Use equidistant calculation: with this calculation, the number of intersects in each color level are specified by OSS-ESPA and you cannot edit them. After the analysis is complete, you can view it on the map, where it displays the bins with the highest intersections in red, and the lowest in gray. The Legend panel displays the ranges and the number of bins in each range.

  

• Use percentile calculation: this calculation uses the Excel percentile function. A percentile is a value below which a given percentage of values in a data set fall. You can set four percentile calculations, however the default values are 40%, 60%,80% and 95%. After the analysis is complete, you can view it on the map, where it displays the bins with the highest percentile in orange, and the lowest in gray. The Legend panel displays the exact percentage and the total number of intersections in the range.

  This percentile method of displaying the analysis can be more useful if the area you are running your analysis over does not have a wide range of intersections in the bins. This is because it allows you to spread the color levels over the range of intersections in your specific area, whereas with the equidistant calculation they may all occur in the same level and therefore be displayed with the same color.

  

• Distance and Time: you can optionally select to enter a distance and time from the target location events. Each time the analysis is run, if new data is available within either the distance or time values you set, then a new analysis result folder is created. The allowable distance range is 5 to 20 miles, and the time range is 30 to 120 minutes.

  

After the analysis is complete you can use the Precision location tab to view the precision level color codes and select which ones you want to view. This allows you to view and prioritize the areas with the highest number of intersects. You can also use the Legend panel to view the color codes.