Frequently Asked Questions

No account or download needed. Access ASIT directly. To save surfaces, create an account. Once we grant Premium permission you can import your aerodrome data and start evaluating obstacles.

Yes — all new users receive a 10-day free trial with full Premium access immediately after signing up and requesting one.

Yes. ASIT works on any device with a supported browser. Optimised for desktop; accessible on tablets. We recommend Chrome or Edge.

ASIT has a completely free tier for multiple-point evaluations across ICAO Annex 14, OFS/OES, PANS-OPS, PBN procedure protection areas, BRA, and custom surfaces. Premium plans for batch processing, 3D buildings, world 3D checks, and authority widgets start at €100/month for saved airports.

Yes. The If you need to analyze different sites, export your data, clear one or more workspaces and start fresh with new aerodromes under the same subscription. Over time, the same plan can rotate through unlimited airport sites. The saved-airport limit is the active saved Airport/Group Name count. Each saved Airport/Group Name can contain up to 80 saved surface groups, subject to separate family limits; a group can contain many generated components or polygons.

Because ASIT offers a free tier for base obstacle clearance reviews without any software installation, it is designed to be one of the most accessible and cost-effective obstacle evaluation tools for airports, authorities, developers and aviation consultancies.

Yes, ASIT's Verified Authority plan allows CAAs and Airport Operators to embed an obstacle evaluation widget directly on their website, giving citizens and developers instant checks for antennas, buildings, cranes and other obstacles while generating an automated audit log.

ASIT imports and exports KML, DXF (CAD), AIXM and GeoJSON. Obstacle lists can be uploaded as CSV for batch analysis, and every evaluation can be exported as a professional, authority-ready PDF report. This lets ASIT fit into existing CAD, GIS and AIS/AIM toolchains rather than replacing them.

Yes. ASIT is a full PANS-OPS (ICAO Doc 8168) protection-area construction and obstacle-assessment tool. It builds and evaluates both conventional and PBN procedures — holding, racetrack, base-turn, 45/180 turns, SID, STAR, en-route, approach and missed approach — plus OAS (ILS CAT I/II/III), APV/Baro and VSS/OCS surfaces.

ASIT analyzes up to 1,000 obstacles per CSV batch upload, and you can upload unlimited batches one after another, so total obstacle assessment is effectively unlimited. An interactive on-screen multi-point mode is also available for quick checks.

Yes. ASIT's core surface generation and obstacle analysis are free, and Premium is €100/month — a fraction of traditional desktop PANS-OPS and aerodrome-safeguarding software, which typically costs several thousand euros per seat or per year.

ASIT is a full, editable ICAO surface generator and flight-procedure construction tool, not just an obstacle checker. You generate, fully edit, visualise in 3D and export the actual ICAO surfaces yourself — Annex 14 OLS, OFS/OES, OAS, PANS-OPS, VSS/OCS, BRA, custom surfaces and full PBN and conventional procedure protection areas — and then run obstacle analysis against them.

All ASIT modules are included in the single €100/month Premium plan. There are no per-module fees or paid add-ons — one subscription unlocks every surface type, every procedure-construction module, 3D terrain/building checks, batch analysis, all import/export formats and the authority widget.

Our 3D engine plots against the WGS84 Ellipsoid (GPS), while all aviation data uses Orthometric Heights (Mean Sea Level / Geoid). The difference at any location is called Geoid Undulation and varies globally. The misalignment is purely visual — the generated surfaces and all analysis results are mathematically correct.

The widget uses high-resolution elevation data with a spatial resolution of approximately 1–10 meters (terrain detail). This describes the density of elevation samples, not the vertical measurement error. Elevation accuracy varies by location and terrain, but the data provides a highly detailed and reliable surface model for most use cases. For complete global coverage, a fallback to SRTM30 (~30-meter resolution) data is used where higher-resolution data is unavailable.

Saved surface-group limits apply per Airport/Group Name: 80 groups in total. Within that total: 3 aerodrome/runway OLS groups; 3 heliport OLS groups; 3 vertiport OVS groups; 6 legacy RNAV/RNP APCH groups; 7 navaid BRA groups; 6 VSS/OCS groups; 2 OAS groups; 3 OFZ/OES groups; 30 custom/imported groups; 3 APV Baro-VNAV groups; 12 PBN procedure groups; and 8 combined holding/racetrack/base-turn/45/180 procedure-turn groups. Legacy standalone wind-spiral groups have a separate cap of 8. A group is one saved definition and may contain many generated surface components. Temporary guest or non-Premium surfaces are not saved and do not consume these quotas. Each PBN procedure is also limited to 20,000 generated polygons.

Yes, although you will need to contact us first, keeping in mind the terrain-surface vertical offset.

Yes — select a time frame in the audit log and all authorisations requested by free users will appear.

Contact us at contact@altitudenexus.com. We respond quickly and fix critical bugs promptly.

All modern browsers: Chrome, Firefox, Edge and Safari. Chrome or Edge recommended for best performance.