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#1
david17tym

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Happy New Year all,

I have a question relating to best practice when it comes to picking a map projection in the US, I'm based in the UK.

Up to now, the distribution of my source data means I've been picking the relevant State Plane or UTM, but what do you do when the data is spread out further, say over three-four states E-W/N-S (~15 degrees), goto continental systems? just wondering if there was any standard conventions around this?

Thanks,

Dave



#2
Strebe

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People seem to do what is expedient. Often this means simply excerpting from a projection of the entire lower 48 states, such as on Albers or Lambert conic conformal.

Happy new year,
— daan

#3
hasecbinusr

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The projection you select should be entirely based on the purpose of the map. There are a multitude of options depending on what's most important to you in regards of conformity, equal area, equal distance, etc. What qualities of the map will be most important to you?

 

That being said, I find that I often use a Lambert Conformal Conic with the parameters adjusted for my focus area for general purpose mapping.



#4
Dennis McClendon

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^Same.  For any subcontinental map where I'm starting from scratch, I'll make some notes about the extent I plan to use and modify the central meridian and standard parallels in a Lambert projection.

 

One of my standing maps, however, is North America with carefully drawn curving rivers and highways, already in Illustrator.  So for other projects involving roughly 20% of the Lower 48 or more, I just clip from that and rotate it to make vertical the meridian-based state boundaries in the middle of the frame.


Dennis McClendon, Chicago CartoGraphics
chicagocarto.com

#5
david17tym

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Thanks for your help guys.

I understand the principles of optimum projection choice, I was more interested in which ones were instant gotos for native cartographers for general mapping.

Looks like Lambert Conic in this case...






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