[PROJ] Canada Lambert Conformal Conic Projection

[Jeff McKenna]

Hi James,

Some background on the 'Canada Lambert Conformal Conic' projection 
(because this is the one place that we can discuss this kind of 
background) :

You will remember the many years we all leveraged 'custom' EPSG codes to 
handle this projection, as there was no official EPSG code as you said. 
EPSG:42304 was advertized by NRCan as the projection for all web 
services for the Canada Atlas, but since that EPSG code didn't exist it 
would cause much grief for clients, as you wrote here.  This was for 
several years.  Finally in 2008 I submitted this projection to the EPSG 
Registry, and it was approved in 2009 as EPSG 3978 and 3979.  Fast 
forward to today and all of the Canada Atlas OGC services advertize 
EPSG:3978 as its default projection for WMS services.

Some GeoGratis/NRCan data documentation though is older (your link is 
from 2010) and does not mention these EPSG changes.

I have since submitted several Canadian-related projections to the 
registry, and all have propagated to FOSS4G tools now.

Here is the approved change request stored in the EPSG Registry:

   Code: EPSG::2009.012
   Reporter: Jeff McKenna; Gateway Geomatics
   Request: Add Canada Atlas LCC
   Actions Taken: Added proj 3977 and projCRS 3978-79.
   Report Date: 2009-02-19
   Closed Date: 2009-06-02

Happy easter weekend,

-jeff



-- 
Jeff McKenna
MapServer Consulting and Training Services
https://gatewaygeomatics.com/



On 2020-04-10 7:08 p.m., James Banting wrote:
> Hi All,
> 
> I'm creating a STAC catalog for Canada's SPOT4/5 orthoimagery 
> <https://open.canada.ca/data/en/dataset/d799c202-603d-4e5c-b1eb-d058803f80f9> and 
> I’d like to build a proj json file and include it in the STAC items.
> The proj json schema files seem to indicate that I need an `id` object 
> with `authority` and `code` to be compliant. Since the projection 
> (Canada Lambert Conformal Conic [CSRS]), doesn’t have an EPSG code, I 
> used this:
> "id": {
> "authority": "CANLAMB-CSRS",
> "code": 1
> }
> 
> *Is this acceptable in proj world? It’s been a while since I’ve had to 
> touch projection files.*
> 
> As a reference, this is the documentation for the CANLAMB projection 
> <http://ftp.geogratis.gc.ca/pub/nrcan_rncan/image/spot/geobase_orthoimages/doc/GeoBase_spot_en_Orthoimage_Specifications.pdf> (pg 
> 9 of the document, 15 of the pdf) and I’ve attached my take at the proj 
> json file.
> 
> Thanks,
> --
> James Banting
> Sparkgeo
> 
> 
> 
> 
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