Polar sweep over terrain accurate path profiles
Coverage is predicted on a polar grid centred on the tower. Every bearing and ring cell samples its own terrain profile from the Mapbox global Terrain RGB DEM at a configurable density, applies earth curvature at a standard atmosphere effective earth radius following ITU-R P.530, and resolves the chord independently. Rasterisation runs off the main thread so the map stays responsive while a study lands.
Automatic propagation model selection, recorded not hidden
Hata Okumura and COST 231 are used when the chord sits inside their published validity: 150 to 2000 MHz, base height 30 to 200 m, mobile height 1 to 10 m, range to 20 km. Outside that the engine falls back to the NTIA reference Irregular Terrain Model, valid from 20 MHz to 20 GHz. ITU-R P.1546 and P.1812 are available on the same terms. The decision is recorded in the run manifest and preserved on each cell, and either model can be forced for a sensitivity study.
Diffraction, clutter, vegetation and building entry as explicit layers
ITU-R P.526 single knife edge diffraction with a mid path bulge approximation is applied to blocked bearings so they receive realistic fade margins rather than nulls. P.2108 clutter height gain corrects for terminals below rooftop or canopy top, keyed on ESA WorldCover land cover sampled per profile point. P.833 adds depth aware woodland loss over forest cells, bounded so it never double counts the representative clutter. P.2109 building entry loss converts outdoor field strength to an indoor prediction for traditional or thermally efficient construction at a percentile you set. Each contribution stays separately visible in the cell loss stack.
Measured antenna library with pattern preview
Set a service antenna from a filterable library of real measured antennas rather than a generic omni or sector. Filter the whole catalogue by search text, source, manufacturer, series, band and minimum gain, with in band antennas floated to the top for the service frequency, preview the azimuth and elevation radiation pattern before you commit, and apply the vendor gain, polarisation and measured pattern in one click so the directional sweep uses the real pattern.
One study, many views
A single sweep re renders into talk out, talk back and worst of, which is the two way usable coverage an integrator actually signs off. Coverage area is a binary mask, coverage probability shows per cell confidence against the combined uncertainty, C over I plus N exposes multi site interference, number of servers highlights hand off zones, field strength in dBuV per metre supports contour filings, and BER covers TETRA, P25, DMR, NXDN and analogue FM. Multi site simulcast networks add simulcast receive and delay spread. Switching views does not re run the engine.
Drive test calibration folded into the uncertainty
Measured field readings import from generic CSV or NMEA, with auto detection of TEMS Investigation, Nemo Outdoor and JV Mobile exports. The engine computes the residual against the prediction and applies either a constant offset or a per-environment bias and sigma bucketed by land cover, with a hold-out accuracy check so the fit is not flattering itself, and propagates the residual sigma through the per cell uncertainty quadrature so the reported combined sigma reflects measured residual. A validation pack reports mean error, RMSE, sigma, correlation, the measured-versus-predicted regression and percent within 6, 10 and 15 dB, overall and per clutter class, and exports a reproducible CSV. The calibration state travels in the run manifest.
Two reliability percentiles that are not the same thing
Location reliability drives the lognormal slow fading margin and models the spatial distribution of users within a cell. Time reliability is orthogonal and covers the fraction of time a link clears its threshold at a fixed point. On the empirical base models the time variability sigma is an internal engineering estimate rather than an ITU validated figure, and it is disclosed as such in the run manifest rather than presented as a published number. The ITM and P.1812 paths use their own published time variability.
Per cell provenance
Hover any cell for its received level, fade margin, tier, distance and bearing, the full loss stack from base model through diffraction, clutter, building entry and body loss, and the combined sigma from the uncertainty quadrature. This is what makes a prediction arguable rather than a colour on a map, and it is what survives into every export.
Comparison, optimisation, frequency planning and ACMA precheck
The comparison workspace diffs two studies with a coverage delta raster and area statistics for alternate site, height or service mix work. The optimiser sweeps candidate tower heights, tilts and azimuths and ranks them against a coverage objective. The frequency plan workspace builds a network wide channel matrix and flags reuse conflicts by carrier to interference severity. The regulatory workspace runs an ACMA precheck against the bundled RALI rules and the live RRL.
Models cross checked against independent implementations
The propagation models are validated against executable reference code rather than hand transcribed tables: eeveetza Py1546, Py1812 and Py452 from the ITU-R SG3 rapporteur, itmlogic for Longley-Rice, and ITU-Rpy for rain, with reference outputs committed as fixtures the test suite checks against. The composition from terrain sample through model selection, diffraction, clutter and tiering is proven end to end by test.