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Site Navigator US is a free field tool for locating FCC-registered antenna structures across the United States. It provides fast access to 141,370 constructed towers sourced from the FCC Antenna Structure Registration (ASR) database.
Search any FCC Antenna Structure Registration Number instantly β for example 1043234. Results show the registered coordinates, structure owner, structure type, and overall height above ground. The ASRN is the number physically posted at the base of every registered tower.
Use your device's GPS to find the closest registered antenna structures to your current position. Results are sorted by distance and include the bearing for field navigation and radio-link alignment.
All tower data is sourced from the FCC ASR public database, which is in the public domain. It covers registered antenna structures over roughly 60 m or near airports β including lattice towers, guyed towers, monopoles, and masts β owned by tower companies such as American Tower, SBA, Crown Castle, and Vertical Bridge, as well as carriers and thousands of independent owners.
Align a microwave or radio link to a target tower using your phone's compass and GPS. Site Navigator US computes the precise bearing to the target and works as a low-cost companion to dedicated alignment hardware.
An ASRN (Antenna Structure Registration Number) is the FCC identifier for a registered antenna structure. The FCC requires the ASRN to be displayed at the base of the registered tower, so field crews can confirm they are at the correct structure.
Use the GPS Nearest feature. The app uses your device location to load the registered structures around you and lists them by distance.
Tower data comes from the FCC ASR public database (public domain). Weather data is provided by Open-Meteo (CC BY 4.0). Fuel station data comes from OpenStreetMap contributors under the ODbL licence.
Yes. Site Navigator US is a personal project built for field use by tower technicians and riggers. It requires no registration or login for core features.
Coordinates come directly from the FCC ASR registry and reflect officially registered structure positions. Structures under roughly 60 m that are not near an airport are generally not in the ASR database; for those, you can enter the coordinates from your work order manually.
Site Navigator US is a Progressive Web App (PWA) and can be added to your home screen on Android and iOS. Tower areas you have already viewed work offline after first load. Weather and fuel data require an internet connection.
Site Navigator US was built by Arek Jankowski as a field tool for US tower technicians. Contact: inter.arnet@gmail.com