Aero API - Altitude

Hi - I am using the Aero API to perform some safety calculations. Unlike Firehose, the AeroAPI only provides one altitude field. The documentation does not specify what “Altitude” is (aside from units):

  • Is it AMSL / AGL / Above WGS-84 Ellipsoid?
  • Is this an actual altitude (geometric / geopotential)? or is it a barometric pressure measurement converted to altitude using standard atmosphere.


Since the data is aggregated from multiple sources, the nature of the altitude can be a mix of multiple sources throughout a flight. When the position is derived from ADS-B, it may sometimes be GPS sourced, however if it is under ATC coverage then it will usually be uncorrected pressure altitude. Also keep in mind that the transponder altitude accuracy is typically only legally mandated to be within +/- 200 ft (may vary by jurisdiction).

In general, I would not recommend relying on the accuracy of the altitude if your requirements are sensitive enough to force you to know the nature of how it was measured and correct for it. Additionally, our terms of use specify that you should not be using it for “safety-critical activity that relies on the availability, validity, or accuracy”

Thanks for your answer.

Knowing what the reference altitude is (MSL / AGL) makes a big difference since my area of interest has 4000ft ground elevation.

For the price of the data, it would be great to have more details on the altitude reference datum.


None of our aircraft altitudes will ever be reported in AGL, if that helps.