Propagation solver
RESEARCH MODEL · NOT VALIDATED
Numerical refraction through a spatially varying ionosphere. Reciprocal geometry approximation for receive-site footprints.
Electron-density field
ANALYTIC CHAPMAN SCENARIO
D + E + F1 + F2 layers; day/night and geographic variation are explicit assumptions, not IRI output.
Use exported fields or ray results from established engines. IRI / IGRF, PHaRLAP, NOAA D-RAP and ITU models are managed in MODELS. The desktop edition bundles native model engines; this browser edition runs offline IRI-derived climatology, numerical rays and ITU noise.
Frequency comparison
Each frequency is modeled independently. Receiving more channels does not change an unknown transmitter's frequency.
Receiving-site inventory
Additional candidates
Incremental benefit in 16 seasonal/hour scenarios. Fast spherical-shell screen only; no deployment-access assumption.
Network coverage screening
FAST SCREEN · NOT THE 3D RAY SOLVERAnnual results are assumption-based feasibility screens, not physical coverage, a geolocation-error forecast, or a 24/7/365 guarantee.
Three co-frequency receivers, at least one AOA site, and bearing diversity are required by this screen. No signal correlation or calibrated AOA/TDOA error is modeled.
Hours passingNot run
Worst-hour screened area—
Audit statusNot run
Full-year audit samples 365 days × 24 UTC hours. Solar/density assumptions remain as configured. Extreme events, receiver failures, interference variability, and finer spatial/time gaps are not certified.
Browser numerical mathematics
H = (p·p − n²) / 2
dr/dλ = ∂H/∂p
dp/dλ = −∂H/∂r
p = c k / ω
Isotropic: n² = 1 − fₚ²/f²
Adaptive Dormand–Prince 5(4) integration in three Earth-centered dimensions, spatial gradients, dispersive group delay, event-located ground returns, and Hamiltonian-residual checks.
Browser magnetoionic research mode
Collisionless Appleton–Hartree O/X branches with directional derivatives and an illustrative tilted-dipole magnetic field. This is not PHaRLAP or IGRF. Magnetic modes are restricted to one hop; no polarization conversion or nonreciprocal receive-footprint certification.
What a footprint means
Dots are numerically calculated ground returns. Shaded patches interpolate neighboring returned rays and are not a continuous coverage guarantee. Loss filtering excludes high modeled attenuation; it does not predict receiver SNR. A top-of-grid exit is not proof of escape to space.
Verification without field deployment
Check vacuum/analytic limits, conservation residuals, step-size convergence, and independent-engine agreement. Existing archived measurements may support later validation. Simulation self-consistency alone does not establish real-world accuracy.
Best-available integration path