True heading from PPK processed data output in ENU format

Emlid Studio Static / Kinematic processing
1

Hi there, have used Emlid Studio in Kinematic mode to process two RINEX files from GNSS receivers that are essentially in a moving baseline mode.

To be more specific, the GNSS receivers were mounted on a ship at the bow and stern, which whilst moored alongside a pier was subject to the effects of tide and wash of passing ships etc.

I am trying to achieve true heading by outputting from Emlid Studio in E/N/U-Baseline format, then doing some math to calculate the heading based on the dE & dN output. However, when comparing with online PPP processed data and computing azimuth from Latitude and Longitude I get some 2° bust in heading.

Normally on a UTM derived E/N output we would apply a convergence value to convert from Grid North to True North, but that is a function of the distance from the central meridian. How does one apply the equivalent of this convergence to ENU coordinates to get True Bearing? Do I need to transform the ENU coordinates into ECEF and then calculate the heading?

Any help would be much appreciated.

3

Hi Mark,

Welcome to our community!

I can hardly suggest something specific, but I know some of our users worked on similar setups. For instance, you can check the discussion in this thread. Maybe they can provide more details.

5

Hi there,

Thanks the reply. I took a look and whilst very similar, it’s not quite the same.

They are trying to calculate heading on the fly from the Lat & Long positions on the ECEF, whereas I am calculating heading from the Eastings / Northings on ENU.

Thanks for the suggestion though.

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