Adjusts raw altitude estimate so that it outputs relative altitude above elevation layer (DEM) surface if available. Previously this worked only because (1) the KSQL Airport simulation starting altitude is very close to MSL and (2) the area is practically flat with the exception of buildings.
Notes:
Collects different definitions of altitude under one dataclass ("Altitude"). See ArduPilot's altitude definitions which are used here as well.
DEM layer units are assumed to be meters but origin is unknown (e.g. USGS DEM uses NAVD 88). This PR assumes the home position is on the DEM surface (ground) and therefore uses the home position reference altitude to fix DEM origin.
Defines altitude above ground level (AGL) purely as distance to DEM (or flat plane defined by starting location if no DEM is available). Does not consider e.g. altitude estimates from things like laser range finder that could be different from estimated distance to DEM surface and that would therefore introduce another "definition" of altitude that would have to be handled separately.
Other:
Typo corrections in README.md and Sphinx docs
Link to Jupyter variance estimation notebook added to relevant section in Sphinx docs
Adjusts raw altitude estimate so that it outputs relative altitude above elevation layer (DEM) surface if available. Previously this worked only because (1) the KSQL Airport simulation starting altitude is very close to MSL and (2) the area is practically flat with the exception of buildings.
Notes:
Other: