How do I convert coordinates to a Latitude & Longitude?

Question

I am reverse engineering a transportation visualization app. I need to find out the latitude for the origin of their data feed. Specifically what XY 0,0 is. The only formula

Answer 1

Ask them what coordinate system they're using! (or if you got the dataset from some database, look at the metadata for the dataset and it should tell you. Otherwise I'd be skeptical of its value)

Most likely this is one of the state plane coordinate systems. They're for localized areas of the earth (kind of like UTM), and are frequently used for surveying.

You can use CORPSCON (or other GIS programs; ExpertGPS will do this if you have the GIS Option Pack but it's not free. I forget whether GPSBabel does conversion) to convert between lat/long and any of the state plane coordinate systems. You'll also need to know which datum the coordinates are in. WGS84 and NAD83 are very close but NAD27 is different.