Can I use ASIT on different devices?

Yes! You can use ASIT on different devices with supported browsers. The application is optimised for desktop use, but it is also accessible on tablets.

Yes, you may occasionally notice a vertical misalignment between the 3D terrain and your generated protection surfaces. This happens due to the fundamental difference between how digital 3D mapping engines and the defined surfaces' altitude. The error is just a visual misalignment, but the created surfaces and analysis are correct!

1. The 3D Engine (WGS84 Ellipsoid)

Our 3D globe visualisation engine plots coordinates against the WGS84 Ellipsoid. The ellipsoid is a perfectly smooth, mathematical shape used by GPS systems to model the Earth. In this digital environment, an altitude of 0 meters means resting exactly on this smooth, hypothetical shell.

2. The Aviation Standard (Mean Sea Level / The Geoid)

Aviation, however, relies on gravity and atmospheric pressure, not just geometric math. All official aeronautical data—including ICAO Annex 14 criteria, PANS-OPS procedures, runway elevations, and legal obstacle heights—are strictly defined using Mean Sea Level (MSL) (Orthometric Height). MSL is based on the Geoid, a bumpy, irregular surface shaped by the Earth's varying gravitational pull.

The Discrepancy (Geoid Undulation)

Because the Earth's density is uneven, the Geoid (MSL) naturally undulates above and below the smooth WGS84 Ellipsoid. Depending on your global location, MSL can be below or above the WGS84 ellipsoid. We try to counter this, but it is not always exact, which is why there is a small misalignment.

If an application plots an aviation surface (defined in MSL) directly onto an uncorrected 3D terrain model (defined in WGS84), the surface will appear physically misaligned—either floating too high in the sky or buried beneath the ground.

We have set a generous limitation of Surface groups per set of airports:

• 3 complete OLS

• 6 RNP APCH

• 7 Navaid BRAs

• 6 VSS

• 3 OFZ/OES

• 30 custom surfaces

Yes, although you will have to contact us, keeping in mind the terrain offset with the surfaces offset

Yes, you can easily access all of the authorisations requested by free users, just select a time frame and the log will appear!

Yes! Please report bugs or request improvements to contact@altitudenexus.com with a description, steps to reproduce and screenshots. Critical issues receive expedited response times.
If there is a new feature you would like us to add, we will try our best to offer it! We are compromised with our client's satisfaction.

Yes, our system processes your coordinate data to perform the mathematical evaluations. If you are using a Registered/Premium account, the coordinates (Lat, Lon, Alt) and the evaluation results are saved to an encrypted database strictly to generate your secure Audit Logs and historical PDF reports. (Only in case an authorisation PDF is generated, not for quick analysis).

Your airport-defined surfaces may also be defined as private instead of public.

We do not monitor, share, or sell any of this operational data. Your data is siloed to your specific account, hosted on secure cloud infrastructure, and is inaccessible to the public or other users. 

If your organization requires a Non-Disclosure Agreement (NDA) or a specific Data Processing Agreement before using the tool, we would be more than happy to sign one.