1. Grid Systems

2. Transverse Mercator Projection

3. Copyright © 2009 by Maribeth H. Price 3-3 South Dakota Zone 16 Universal Transverse Mercator Based on Transverse Mercator (cylindrical) projection World divided into 60 zones 6 degrees wide Distortion is minimal within each zone Maps of different areas use best zone Best for maps covering small area in one zone

4. UTM Zones

5. UTM Pole to Pole

6. Halfway to the Pole

7. Using UTM

10. Three Kinds of North True North – Along Meridians Magnetic North – What a compass detects – Important in field – Not important in most GIS Grid North – Along N-S grid lines – Minor importance for compass work – Be aware there’s a difference! – Military uses exclusively

11. Cautions About UTM Military maps use two letter codes for each 100-km square, but maps will have information to enable conventional UTM With military grid references, number of digits indicates level of precision Older maps will sometimes have obsolete grids Datum, datum, datum!

12. Military Grid System 45N 89 W = E 342,369, N 4,984,896 Zone 16T Digraph = CQ 1 km accuracy = 16T CQ 42 84 100 m accuracy = 16T CQ 423 848 10 m accuracy = 16T CQ 4236 8489 1 m accuracy = 16T CQ 42369 84896 Ticks on USGS topo map = 3 42,000, 4,9 84,000

13. Where Zones Meet

14. Why a Grid? Latitude /LongitudeGrid System North varies from place to place on the map Grid north is always the same direction Angular units differ in scale between N-S and E-W Grid scale the same in all directions E-W angular units vary in scale with latitude Grid squares are always the same size and shape Hexadecimal ScaleDecimal Scale

15. Copyright © 2009 by Maribeth H. Price 3-15 State Plane System States divided into one or more zones identified by a unique FIPS number Uses several types of projections E-W zones generally Conic, N-S zones generally UTM

16. Copyright © 2009 by Maribeth H. Price 3-16 Projections for large scale maps Local, city, county maps, smaller states – Projection systems virtually eliminate distortion – Choose appropriate UTM or State Plane zone

17. Wisconsin State Plane Zones

18. Wisconsin Grid Systems

19. Copyright © 2009 by Maribeth H. Price 3-19 Projections for smaller scales Distortion is inevitable, so purpose drives the choice – Equidistant maps when distances are important – Equal area maps when areas are important – Conformal or compromise projections for general purpose maps Coordinate system names generally indicate the locale and purpose it is optimized for. Use for clues to choice.

20. Metes and Bounds System

21. Public Land Survey System AKA Congressional System Established 1785 Does not apply to: – 13 Original Colonies – Derivative States (VT, KY, TN, ME, WV) – Texas (Former independent country) – Hawaii (Uses Kingdom of Hawaii system) Land Division – 6 x 6 mile townships, 36 sections, quarter sections

22. USA Public Land Surveys

23. Non- Congressional Grids

24. Before Greenwich

25. Arbitrary Geography

26. More Arbitrary Geography

27. Grid vs. No Grid

28. Gridded Landscape

29. Where Wisconsin’s Grid Starts

30. Where California’s Grid Starts

31. Section Numbering

32. Wisconsin Townships

33. Township Labels

34. Section Descriptions

35. Limitations of the Congressional Land Survey System

36. Congressional Land Survey System Not an accurate grid! Locations within subdivisions may be imprecise Data points used in GIS may be tied to system Authoritative surveys are forever – French strips in LA, MO, WI – Spanish and Mexican land grants

37. French Long Lot System

39. California: PLSS and Land Grants

41. Oh, Canada Eastern Canada: Metes and Bounds, Long Lot Northern Ontario: 6 and 10-mile townships Western Canada: Dominion Land Survey – Modeled on PLSS – 6-mile townships – Townships numbered N-S with Arabic numerals – Ranges numbered E-W with Arabic or Roman numerals – Road allowances between sections – Sections zigzag from 1 in SE to 36 in NE (Opposite US) – ¼-1/4 sections numbered from 1 in SE to 16 in NE

42. Dangers of Cheap Work

43. Missed It By That Much