Funding for this site is provided by the cooperators / programs below:

United States Army

This site uses multiple sensors, and possibly sensor types, to measure gage height. The final usable published data series is presented as the Primary Sensor. The Secondary and Tertiary Sensors are used to fill in for the Primary Sensor when the Primary Sensor is either damaged or less accurate.

A red line on the gage height graph indicates the minimum or maximum operational gage height limits of the respective sensor.