Spanline is a free browser-based microwave path design and link budget application. Import and export native Pathloss 5 (.pl5) files, run ITU-R and North American availability and diffraction studies over automated USGS 3DEP terrain, LiDAR, and clutter profiles, and generate path survey reports and design exports directly in the browser.
Built for point-to-point microwave link designers and network planners who need fast, reproducible link budgets, terrain/LiDAR obstruction clearance, and native Pathloss 5 interoperability without a Windows desktop dongle.
.pl5) Round-Trip Import & Export
Open existing Pathloss 5 .pl5 link files and .rsd radio specification files directly in the browser. Spanline preserves site coordinates, call signs, antenna heights, waveguide losses, ACM profiles, terrain profiles, and the 840-byte terrain-roughness trailer on round-trip export.
Built-in 77-item catalog (8 radios, 29 antennas, and 40 transmission lines) spanning Nokia/Wavence, Aviat Networks, Ceragon, Cambium, CommScope/Andrew, RFS, and Times Microwave—plus any vendor via Pathloss .rsd import or custom catalog entry, with 10-mode Adaptive Coding & Modulation (ACM) and ATPC.
Switch seamlessly between Vigants–Barnett + Crane (North America, 200+ US city rain curves) and ITU-R P.530-17 + ITU-R P.837/P.838 availability and rain fading, paired with ITU-R P.1510-0 annual temperature, ITU-R P.676 gaseous absorption, and ITU-R P.526-15 diffraction (Delta-Bullington, Deygout, classical Bullington, and single knife-edge).
Fetch bare-earth elevation from USGS 3DEP (with global Open-Meteo DEM fallback) and overlay USGS 3DEP LiDAR Height Above Ground (HAG), LANDFIRE canopy height, OpenStreetMap 3D building footprints, and Annual NLCD land-cover clutter classes with user-adjustable obstacle heights.
Search the integrated US FCC Antenna Structure Registration (ASR) database by registration number or coordinate radius to populate site structures. Evaluate dual-K Fresnel zones (e.g., 1.0 F1 at K=4/3 and 0.6 F1 at K=2/3), inspect reflection/grazing points, and run the 1-Click Auto Antenna Height Optimizer.
Generate Pathloss-style Microsoft Word .rtf reports with embedded vector EMF profiles, printable landscape/portrait Path Survey PDFs, multi-hop 3D Google Earth .kml files with Fresnel envelopes, and Project Multi-Hop Summary & Equipment BOM .csv spreadsheets.
Explore a multi-hop project on the interactive map, inspect sample-by-sample terrain and LiDAR clearance, and audit every decibel of the transmission and availability worksheet.
Multi-hop network map, great-circle distance and azimuths, FCC ASR tower lookup, and one-click terrain/clutter/LiDAR fetch.
Interactive earth-curved terrain profile with dual-K Fresnel envelopes, LiDAR/clutter heights, specular reflection solver, and height optimizer.
Full EIRP, free-space/atmospheric/diffraction loss, RSL, thermal fade margin, multipath/rain outage seconds, and per-ACM-mode availability.
Full documentation of the mathematical models and binary file structures is available on the Spanline Documentation & Overview pages.
| Subsystem | Supported Standards, Datasets & Capabilities | Reference |
|---|---|---|
| Pathloss 5 & Radio Files | Native binary .pl5 import and round-trip export (preserving the 840-byte roughness trailer), plus Pathloss .rsd radio specification import and JSON project archives. |
.pl5 Import Docs → |
| Propagation & Availability | Vigants–Barnett (North America) and ITU-R P.530-17 multipath fading; Crane (US city rain zones) and ITU-R P.837 / P.838 rain attenuation; ITU-R P.1510-0 annual surface temperature; ITU-R P.676 gaseous absorption (O2 + H2O). | Link Budget Docs → |
| Diffraction Models | ITU-R P.526-15 Delta-Bullington (spherical earth + Bullington), Deygout multi-edge, classical Bullington, and single knife-edge diffraction loss integrated into RSL and fade margin. | Link Budget Docs → |
| Terrain, Clutter & LiDAR | USGS 3DEP bare-earth DEM, USGS 3DEP LiDAR Height Above Ground (HAG), LANDFIRE canopy height, OpenStreetMap 3D buildings, Annual NLCD land-cover clutter, and global Open-Meteo 90 m DEM fallback. | Feature Matrix → |
| Equipment & ACM | 77-item catalog (8 radios, 29 antennas, 40 transmission lines) across Nokia/Wavence, Aviat Networks, Ceragon, Cambium, CommScope/Andrew, RFS, and Times Microwave, plus custom entries, 10-mode ACM, and ATPC. | Feature Matrix → |
| Reports & Deliverables | Microsoft Word .rtf (Pathloss-style layout + vector EMF profile), Path Survey PDF print layout, Google Earth 3D .kml, and Multi-Hop Summary & BOM .csv. |
Launch App → |