georeferencing with paper maps

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

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Georeferencing with Paper Maps. Museum of Vertebrate Zoology University of California, Berkeley & Royal Ontario Museum, Toronto. Overview. Map Anatomy Scale Grid Datum Publisher Georeferencing with Paper Maps Latitude and Longitude Mathematically Error Calculator. - PowerPoint PPT Presentation

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Page 1: Georeferencing with Paper Maps

Georeferencing with Paper Maps

Museum of Vertebrate Zoology University of California, Berkeley

& Royal Ontario Museum, Toronto

Page 2: Georeferencing with Paper Maps

Overview Map Anatomy

Scale Grid Datum Publisher

Georeferencing with Paper Maps Latitude and Longitude Mathematically Error Calculator

Page 3: Georeferencing with Paper Maps

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

Page 4: Georeferencing with Paper Maps

Map of Canada’s Wonderland, N of Toronto, Canada

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Page 5: Georeferencing with Paper Maps

Map Anatomy: Map Scale

Page 6: Georeferencing with Paper Maps

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

Page 7: Georeferencing with Paper Maps

Map Anatomy: Map Scale 1:25,000 Large Scale

Page 8: Georeferencing with Paper Maps

Map Anatomy: Map Scale 1:250,000Smaller Scale

Page 9: Georeferencing with Paper Maps

Map Anatomy: Map Scale 1:500,000

Smaller than before

Page 10: Georeferencing with Paper Maps

Map Anatomy: Map Scale 1:1,000,000 Small Scale

smaller than before

Page 11: Georeferencing with Paper Maps

Map Anatomy: Grid

Page 12: Georeferencing with Paper Maps

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

Page 13: Georeferencing with Paper Maps

Map Anatomy: Grid

Map with no grid labeled

Page 14: Georeferencing with Paper Maps

Map Anatomy: Datum

Map with no grid labeled

Page 15: Georeferencing with Paper Maps

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 http://earth-info.nga.mil/GandG/publications/tr8350.2/wgs84fin.pdf (Use Appendix B)

Page 16: Georeferencing with Paper Maps

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”

Page 17: Georeferencing with Paper Maps

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)

Page 18: Georeferencing with Paper Maps

Coordinate Integers for Hemispheres

Page 19: Georeferencing with Paper Maps

Determining Coordinates from Paper Maps

Nauru Island, Pacific Islands Geographic Nauru Island, Pacific Islands Geographic

Society, 1960 1:12,000Society, 1960 1:12,000

Page 20: Georeferencing with Paper Maps

Determining Coordinates from Paper Maps: Latitude

Page 21: Georeferencing with Paper Maps

Determining Coordinates from Paper Maps: Latitude

S

Page 22: Georeferencing with Paper Maps

Determining Coordinates from Paper Maps: Longitude

Page 23: Georeferencing with Paper Maps

Determining Coordinates from Paper Maps: Longitude

E

Page 24: Georeferencing with Paper Maps

Determining Coordinate Precision

Determining Coordinate Precision for the Georeferencing Calculator:Determining Coordinate Precision for the Georeferencing Calculator:

The smallest measurement using our rulers is 1 mm ( = 0.01 cm), The smallest measurement using our rulers is 1 mm ( = 0.01 cm), therefore we need to convert millimeters to minutes:therefore we need to convert millimeters to minutes:

0.1 cm x (2 minutes/14 cm) = 0.014 min0.1 cm x (2 minutes/14 cm) = 0.014 min

Choose the next largest fraction of a minute on the calculator.Choose the next largest fraction of a minute on the calculator.

For 0.014 minutes, select 0.1 minutes.For 0.014 minutes, select 0.1 minutes.

Page 25: Georeferencing with Paper Maps

Determining Coordinates from Paper Maps: Error Calculation

Page 26: Georeferencing with Paper Maps

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

Page 27: Georeferencing with Paper Maps

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 Lat and Long:

Determining Coordinate Determining Coordinate Precision:Precision:

0.1 cm x (2 minutes/14 cm) = 0.014 min0.1 cm x (2 minutes/14 cm) = 0.014 min

Round up to 0.1 minute precisionRound up to 0.1 minute precision