Magnetic declanation

[seabilwe]

• Use this ticket from https://github.com/kartoza/SAGTA/issues/20 as a guide and the annexure in the Dominica topo guidelines. DomiNode - Cartographic Standards Guide.docx

[seabilwe]

The magnetic declination plugin in qgis is used in the map templates to calculate the magnetic declination of St Lucia

[vikineema]

The magnetic declination for the St Lucia map sheets is calculated from the position 60.9673212°W, 13.898574°N as at 7th June 2021, using the National Centers for Environmental Information's Declination Magnetic Field Calculator. This calculator utilises the World Magnetic Model (WMM) - 2020 provided by the NCEI National Centers for Environmental Information.

The UTM convergence angle was calculated from the position 60.9673212°W, 13.898574°N as at 7th June 2021, using the SharedGeo Magnetic Declination Diagram Service.

[NyakudyaA]

The magnetic declination for the St Lucia map sheets is calculated from the position 60.9673212°W, 13.898574°N as at 7th June 2021, using the National Centers for Environmental Information's Declination Magnetic Field Calculator. This calculator utilises the World Magnetic Model (WMM) - 2020 provided by the NCEI National Centers for Environmental Information.

The UTM convergence angle was calculated from the position 60.9673212°W, 13.898574°N as at 7th June 2021, using the SharedGeo Magnetic Declination Diagram Service.

@vikineema If you want you can also create a custom function in QGIS that calculates the magnetic declination based on the plugin. This will just make sure the values are dynamic https://github.com/kartoza/SAGTA/blob/main/plugins/MagneticDeclination/__init__.py

[vikineema]

Updated magnetic declination, magnetic declination annual change and UTM grid convergence angle to be dynamic . Python expression has been added to the SaintLuciaPythonExpression folder.

[seabilwe]

Thank you @vikineema Please add that to the guideline documentation and remove the text that I had initially placed just after the svg picture