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Lambert vs. Lambert Standard

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Mark Brandon
Mark Brandon on 25 Nov 2019
Commented: Mark Brandon on 28 Jan 2020
The Mapping Toolbox has two definitions for the Lambert Conformal Conic Projection: lambert and lambertstd. What is the difference and which one is more commonly used? I have read and understood the documentation:
LAMBERTSTD Implements the Lambert Conformal Conic projection directly on a reference ellipsoid, consistent with the industry-standard definition of this projection.
LAMBERT is an alternative implementation based on rotating the authalic sphere.
What is odd is that nowhere else have I found an explicit indication that there are two definitions for the Lambert projection. I have also found that the two versions of this projection can, in some cases, result in very different coordinates. It would help if somebody could provide more information about why Matlab chose to include two definitions for the Lambert.
Best,
Mark

Answers (1)

Rob Comer
Rob Comer on 28 Jan 2020
Typically, one would use lambertstd, especially if unprojecting an external dataset from x-y (easting-northing) to latitude-longitude, but lambert remains available for compatibility with older code. For the purpose of pure visualization, either can be used.
  1 Comment
Mark Brandon
Mark Brandon on 28 Jan 2020
Thank you for your comment. But what I am looking for is an brief but explicit description about the difference between these two projection equations. The Mapping Toolbox refer to LAMBERTSTD as an "industry-standard definition", but that lacks any concert information. Maybe a better statement is that Matlab's LAMBERTSTD is the more commonly used version of the Lambert projection.
By the way, I did some searching on this topic. The classic USGS publication on map projections by Synder (1987, 1989) only describes one Lambert projection. The PROJ site (https://proj.org/), which has become a widely used source for map projection code, does report a Lambert and a Lambert alternative, but there is no explaination of the difference there.
The reason I am focused on this issue is that, with a past project, I wasted a bunch of time trying to figure out why Matlab's LAMBERT projection did not seem to work. I eventually learned that I should be using the LAMBERTSTD project.
Best,
Mar

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