GTECH RADIO PLANNING TOOLS

Radio Link Line-of-Sight (LOS) Checker

Check terrain clearance and Fresnel zones between two antenna locations.

DEFINE YOUR LINK

Find a GB postcode

Search positions the selected site. A postcode represents an area, not an antenna location.

Select on map

Easting (m)Northing (m)

Antenna height above ground (m)

Select on map

Easting (m)Northing (m)

Antenna height above ground (m)

Frequency (MHz)Fresnel clearance

Earth curvature & refraction

Effective Earth radius factor, k

Constant k approximation. Atmospheric conditions vary; compare assumptions for critical paths.

Example coordinates loaded. Choose your antenna sites on the map or enter coordinates.

Live public terrain

Mapzen / AWS elevation tiles. Variable source detail and survey dates. This version does not use verified 1 m LiDAR.

Proposed link·Shade

PATH ANALYSIS

Terrain & radio clearance

Good radio link planning always starts with a robust understanding of the local terrain and topography.

Set your antenna locations and heights, then check the path.

FROM SCREENING TO SITE DESIGN

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How to use this checker, data & limitations

Check your radio link

Select Site A and Site B, then click their locations on the map, search by postcode or enter Easting/Northing coordinates.
Enter each antenna height above local ground, frequency in MHz and required Fresnel clearance.
Select Check radio link. Inspect the profile, then export CSV, KML or KMZ, or print the analysis.

What the checker calculates

Great circle path distance and true bearing on a spherical Earth; sampled terrain profiles; effective Earth curvature; first Fresnel radius; minimum clearance; free space path loss; and additional height at one end while holding the other end fixed. Values apply to sampled points only. LOS KML/KMZ exports use elevated absolute height antenna positions, masts, the selected k radio axis and translucent F1/F2 surfaces. An oblique opening view shows the 3D geometry; terrain and height datum alignment with Google Earth is approximate.

Profiles use zoom 12 elevation tiles sampled at approximately 25 m intervals, with at least 100 segments. These are screening settings; narrow obstructions may be missed. Tile pixel spacing is not the native source resolution.

What a clear result means

Clearance is relative to the selected terrain data and k factor. Buildings and vegetation are not modelled separately. The composite source may contain surface artefacts. Survey date, vertical datum and native resolution are not established per location in this tool.

This is a geometric clearance tool. It does not predict received signal level, interference, rain fade, availability or mobile/broadcast coverage. Free space loss is a reference value, not total path loss. No claim of full ITU R compliance is made.

Sources & privacy

Terrain: Mapzen / AWS Terrain Tiles. Europe: produced using Copernicus data and information funded by the European Union,EU DEM layers. United Kingdom: © Environment Agency copyright and/or database right 2015. All rights reserved. SRTM and GMTED2010 courtesy of USGS; ETOPO1 courtesy of NOAA. Full terrain attribution.

Map © OpenStreetMap contributors. GB postcode lookup: Postcodes.io. Coordinate conversion: OSGB36 / British National Grid using a Helmert transformation, not OSTN15; allow several metres of horizontal uncertainty. E/N applies to Great Britain.

Calculations run in your browser. Map and terrain providers receive tile requests for the viewed area; postcode searches are sent to Postcodes.io. No GTech project database or account is used.