[Qgis-user] Qchainage plugin

[Tim Fearn]

Hi Chris,
  This makes sense, thanks.  The trail is oriented predominantly North West and is 318 miles so a bit longer than km.  I’ll check out the article and try UTM Zone 10 I think and see how that goes.

Much appreciated!

Tim Fearn

Hi Tim,

EPSG4326 is geographic coordinates, not metres nor feet.  But we're not really interested in the projection of the project, we're interested in the projection of the data set that contains the trail.

The first thing I would try is to project your trail dataset into a relevant rectangular coordinate system.  You don't mention the orientation of your trail but 318 km is fairly long, so you need to be careful in your choice of projections.  For example, a UTM zone is about 360 km wide at the equator, so if your trail is aligned predominantly E-W you may experience some error due to distortion near the edges.  You might benefit by reviewing this Wikipedia article

https://en.wikipedia.org/wiki/Universal_Transverse_Mercator_coordinate_system <https://en.wikipedia.org/wiki/Universal_Transverse_Mercator_coordinate_system>
On Thu, Mar 30, 2023 at 12:51 PM Tim Fearn <mountainprana.map.works at gmail.com <mailto:mountainprana.map.works at gmail.com>> wrote:
Hi Chris,

  The project CRS is WGS 84, aka EPSG 4326.  All layers have been normalized to this CRS and clipped to the study boundaries.

I haven’t tried playing around with various projections to see if that changes anything.  I’m not very well versed on the mathematics behind such things. Appreciate your reply and happy to answer any other questions.


Cheers,

Tim Fearn

> On Mar 30, 2023, at 1:43 PM, chris hermansen <clhermansen at gmail.com <mailto:clhermansen at gmail.com>> wrote:
> 
> Tim and list,
> 
> 
> What is the projection of your data? 
> 
> The more specific information you can share, the more likely it is someone can help you. 
> 
> 
> -- 
> Chris Hermansen · clhermansen "at" gmail "dot" com
> 
> C'est ma façon de parler.




-- 
Chris Hermansen · clhermansen "at" gmail "dot" com

C'est ma façon de parler.
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