1. Georeferencing with Paper Maps
Museum of Vertebrate Zoology
University of California, Berkeley
& Royal Ontario Museum, Toronto

2. Overview Map Anatomy Georeferencing with Paper Maps Scale Grid Datum
Publisher
Georeferencing with Paper Maps
Latitude and Longitude Mathematically
Error Calculator

3. Pros and Cons of Paper Maps
Pros of Paper Maps
Necessary for certain localities, such as distances by road and topographic features, especially when GIS layers are not readily available
Extents more readily obtained
Old paper maps may be the only option for obtaining coordinates for historic localities
Cons of Paper Maps
Time-consuming
Good quality paper maps may be hard to find
Map printing errors

4. Map of Canada’s Wonderland, N of Toronto, Canada4

5. Map Anatomy: Map Scale

6. Map Anatomy: Map Scale
Usually recorded as a ratio, such as 1:100,000, or a fraction, such as 1/100:000
“Large scale” (Fine scale) maps, such as 1/10,000, show finer detail, less area
“Small scale” (Broad scale) maps, such as 1/500,000, show less detail, greater area
Think of “large” & “small” scale as the value of 1 in the fraction.
Example 1/10,000 > 1/500,000

7. Map Anatomy: Map Scale 1:25,000 Large Scale
Tofino
tof 7

8. Map Anatomy: Map Scale 1:250,000 Smaller Scale8

9. Map Anatomy: Map Scale 1:500,000 Smaller than before

10. Map Anatomy: Map Scale 1:1,000,000 Small Scale smaller than before10

11. Map Anatomy: Grid

12. Map Anatomy: Grid
Shows the placement of the parallels and meridians on maps
Used to determine latitude and longitude
Maps with no grid recorded cannot be used to determine coordinates – only to determine extents

13. Map with no grid labeled
Map Anatomy: Grid
Map with no grid labeled

14. Map with no grid labeled
Map Anatomy: Datum
Map with no grid labeled

15. Map Anatomy: Datum
If datum is recorded, usually found near the map scale or publisher’s name
Use Horizontal Datum, not Vertical
Occasionally, if no datum is recorded but the reference ellipsoid is, then one can determine the datum using the pdf document found at (Use Appendix B)

16. Determining Coordinates from Paper Maps: Georeferencing Source
For Georeferencing Sources be sure to include the following:
Publisher name
Map Date
Map Scale
Map name
Example: United States Geological Society (USGS) Topographic Map California, 1956, map scale 1:24,000, map name “Boone”

17. Determining Coordinates from Paper Maps
Paper maps are necessary when gazetteers will not report needed coordinates
Especially useful for distances by roads and topographic features like rivers and mountain ranges
Pay special attention to the grid lines and the hemisphere (latitudes in the southern hemisphere are negative, and longitudes in the western hemisphere are negative)

18. Coordinate Integers for Hemispheres

19. Determining Coordinates from Paper Maps
Nauru Island, Pacific Islands Geographic
Society, :12,000

20. Determining Coordinates from Paper Maps: Latitude

21. Determining Coordinates from Paper Maps: Latitude

22. Determining Coordinates from Paper Maps: Longitude

23. Determining Coordinates from Paper Maps: Longitude

24. Determining Coordinate Precision
Determining Coordinate Precision for the Georeferencing Calculator:
The smallest measurement using our rulers is 1 mm ( = 0.01 cm), therefore we need to convert millimeters to minutes:
0.1 cm x (2 minutes/14 cm) = min
Choose the next largest fraction of a minute on the calculator.
For minutes, select 0.1 minutes.

25. Determining Coordinates from Paper Maps: Error Calculation

26. In Conclusion
Pay attention to whether you should add or subtract the offsets to the grid points
Measure from the center of your feature to the edge for extent
Plot your coordinates to double check your work
Explain any decisions you had to make in the GeoreferenceRemark field
Explain any errors in the locality description in the LocalityErrors field

27. Round up to 0.1 minute precision
For Georeferencing Source be sure to include the following:
Publisher name
Map Date
Map Scale
Map name
Example: United States Geological Society (USGS) Topographic Map California, 1956, map scale 1:24,000, map name “Boone”
Determining Lat and Long:
Determining Coordinate Precision:
0.1 cm x (2 minutes/14 cm) = min
Round up to 0.1 minute precision