Appendix

I. ID Codes II. Latitude and Longitude Distances III. Common CRS Definitions

Appendix I: ID Codes

INCITS 38:2009 ID Codes for US States (formerly FIPS 5-2)
Name ANSI State Numeric Code Official USPS Code
Alabama 01 AL
Alaska 02 AK
Arizona 04 AZ
Arkansas 05 AR
California 06 CA
Colorado 08 CO
Connecticut 09 CT
Delaware 10 DE
District of Columbia 11 DC
Florida 12 FL
Georgia 13 GA
Hawaii 15 HI
Idaho 16 ID
Illinois 17 IL
Indiana 18 IN
Iowa 19 IA
Kansas 20 KS
Kentucky 21 KY
Louisiana 22 LA
Maine 23 ME
Maryland 24 MD
Massachusetts 25 MA
Michigan 26 MI
Minnesota 27 MN
Mississippi 28 MS
Missouri 29 MO
Montana 30 MT
Nebraska 31 NE
Nevada 32 NV
New Hampshire 33 NH
New Jersey 34 NJ
New Mexico 35 NM
New York 36 NY
North Carolina 37 NC
North Dakota 38 ND
Ohio 39 OH
Oklahoma 40 OK
Oregon 41 OR
Pennsylvania 42 PA
Rhode Island 44 RI
South Carolina 45 SC
South Dakota 46 SD
Tennessee 47 TN
Texas 48 TX
Utah 49 UT
Vermont 50 VT
Virginia 51 VA
Washington 53 WA
West Virginia 54 WV
Wisconsin 55 WI
Wyoming 56 WY

INCITS 38:2009 ID Codes for US Territories (formerly FIPS 5-2)
Name ANSI State Numeric Code Official USPS Code
American Samoa 60 AS
Guam 66 GU
Commonwealth of the Northern Mariana Islands 69 MP
Puerto Rico 72 PR
U.S. Minor Outlying Islands 74 UM
U.S. Virgin Islands 78 VI

Appendix II: Latitude and Longitude Distances

Tables for estimating miles / kilometers from degrees:

Length of a Degree of Latitude (WGS 84 Ellipsoid)
Latitude Miles Kilometers
68.71 110.57
10° 68.73 110.61
20° 68.79 110.70
30° 68.88 110.85
40° 68.99 111.04
50° 69.12 111.23
60° 69.23 111.41
70° 69.32 111.56
80° 69.38 111.66
90° 69.40 111.69
Length of One Degree of Longitude (WGS 84 Ellipsoid)
Latitude Miles Kilometers
69.17 111.32
10° 68.13 109.64
20° 65.03 104.65
30° 59.95 96.49
40° 53.06 85.39
50° 44.55 71.70
60° 34.67 55.80
70° 23.73 38.19
80° 12.05 19.39
90° 0.00 0.00

Robinson et. al. (1995). Elements of Cartography (6th ed.). New York: John Wiley & Sons Inc.


Appendix III: Some Common CRS Definitions

The following CRS are pretty common and are included in the EPSG library used by QGIS – no need to custom define them, just search by name or code.

Geographic Coordinate Systems:

+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs 
+proj=longlat +ellps=GRS80 +datum=NAD83 +no_defs

Since WGS84, NAD83, and all geographic coordinate systems are unprojected they will all look like Equirectangular or “Plate Caree” projections regardless of scale. Global view on the left, zoomed into NYC on the right:

Equirectangular ProjectionEquirectangular Projection centered on NYC

Local Projected Coordinate Systems:

+proj=lcc +lat_1=41.03333333333333 +lat_2=40.66666666666666 +lat_0=40.16666666666666 +lon_0=-74 +x_0=300000.0000000001 
+y_0=0 +ellps=GRS80 +datum=NAD83 +to_meter=0.3048006096012192 +no_defs 
+proj=utm +zone=18 +ellps=GRS80 +datum=NAD83 +units=m +no_defs 

Visually the difference between State Plane (on the left) and UTM 18 North (on the right) is almost imperceptible when focused on the NYC area, but both are clearly distinct from the GCS (WGS 84 / NAD 83):

NY Long Island State Plane centered on NYCUTM Zone 18 North centered on NYC

The following CRS are common continental and global projected coordinate systems that are NOT included in the EPSG library that is part of QGIS; you have to custom define them using the proj4 definitions available at http://spatialreference.org/.

Continental Projected Coordinate Systems

+proj=lcc +lat_1=20 +lat_2=60 +lat_0=40 +lon_0=-96 +x_0=0 +y_0=0 +ellps=GRS80 +datum=NAD83 +units=m +no_defs
+proj=aea +lat_1=20 +lat_2=60 +lat_0=40 +lon_0=-96 +x_0=0 +y_0=0 +ellps=GRS80 +datum=NAD83 +units=m +no_defs

Although difficult to see at this scale, visually Albers Equal Area Conic (on the right) looks more compact east to west versus Lambert Conformal Conic (on the left):

North America Lambert Conformal ConicNorth America Albers Equal Area Conic

Global Projected Coordinate Systems

+proj=robin +lon_0=0 +x_0=0 +y_0=0 +ellps=WGS84 +datum=WGS84 +units=m +no_defs
+proj=moll +lon_0=0 +x_0=0 +y_0=0 +ellps=WGS84 +datum=WGS84 +units=m +no_defs

Visually the differences between Robinson (on the left) and Mollweide (on the right) seem clear:

Robinson ProjectionMollweide Projection

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