Elevation, HAAT, Max ERP
The tools below can be used to calculate location coordinates, elevation, height above average terrain (HAAT), and maximum ERP. All sections require the coordinates entered in the Location & Elevation section.
Location & Elevation:
Enter coordinates or select a location to identify its coordinates and elevation. Choose US locations only. In decimal format, enter Latitude as a positive number; Longitude is entered as a positive number and applied as negative automatically. You can click Calculate here to preview the result, or simply fill in these fields and go straight to the HAAT section below — it will run this calculation automatically.
Lat: Example: 41.02987
Lat: Enter DMS format separated by a space (degrees, minutes, and seconds, Example: 41 01 47.5 N)
Long: Example: -92.59838 (All Longitude values in the U.S. are negative.)
Long: Enter DMS format separated by a space (degrees, minutes, and seconds, Example: 92 35 54.2 W).
HAAT (Height Above Average Terrain):
The HAAT calculation requires the location data identified above as well as antenna height. Clicking Calculate below automatically calculates the location elevation from the coordinates entered above and uses it, so there's no need to click Calculate in the Location & Elevation section first. You may further specify the number of radials upon which HAAT is calculated (use 8 unless you have other specific requirements).
Max ERP:
Maximum ERP allows you to compute the maximum effective radiated power, in watts, to be used at a specific location, under FCC Rule 90.205 for Power and Antenna Height Limits. Clicking Calculate below automatically calculates the location and HAAT above (including antenna height), so there's no need to click Calculate in those sections first — just fill in Band and Area of Operations Radius here.