Cassini Soldner (Kenya) in QGIS

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ouma
Posts: 4
Joined: Tue Aug 18, 2020 12:17 pm

Cassini Soldner (Kenya) in QGIS

Post by ouma »

I've successfully used the following custom projection to plot Cassini coordinates centered on Longitudes 35 and 37 respectively without any errors;

Code: Select all

+proj=cass +lat_0=0 +lon_0=35 +x_0=0 +y_0=0 +a=6378350.87 +rf=294.26 +towgs84=-306,-6,-101,0,0,0,0 +units=m +no_defs

Code: Select all

+proj=cass +lat_0=0 +lon_0=37 +x_0=0 +y_0=0 +a=6378350.87 +rf=294.26 +towgs84=-306,-6,-101,0,0,0,0 +units=m +no_defs
This works for cassini in meters, though the same can still work for measurements in feet so long as you define "a" and "+units" in feet.


Your thoughts?

ouma
Posts: 4
Joined: Tue Aug 18, 2020 12:17 pm

Re: Cassini Soldner (Kenya) in QGIS

Post by ouma »

For Cassini Coordinates centered on the equator and the central meridian 39° (valid 38°-40°E) use the following Proj.4 parameters

Code: Select all

+proj=cass +lat_0=0 +lon_0=39 +x_0=0 +y_0=0 +a=6378350.87 +rf=294.26 +towgs84=-321,0,-135,0,0,0,0
NOTE:
These parameters were computed/generated by StackExchange user AndreJ https://gis.stackexchange.com/users/9159/andrej based on data contained in Dr Wayumba's PhD Thesis

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