45 Plotting charts Flashcards
Mercator
Parallels Meridians Scale Shapes Great circle Rhumb line
Properties
Parallels: straight lines, unequally spaced
Meridians: straight lines, parallel, equally spaced
Scale: correct at equator, expands away from equator
Shapes: preserved at equator, but distorts increasingly away from equator
Great circle: curved, convex to nearer pole
Rhumb line: straight lines
Limitations
Excessive scale expansion
Enormous area distortion in higher latitudes
Great circles are plotted as curved lines
Lambert conformal
Parallels Meridians Scale Shapes Great circle Rhumb line
Properties
2 points of tangency
Parallels: concentric circles, meet meridians at right angles
Meridians: straight lines, meet at the pole
Scale: correct at two standard parallels (SP), between SPs it contracts, outside SPs it expands, considered correct over a single sheet
Shapes: approximately preserved everywhere
Great circles: approximately straight lines
Rhumb line: concave to the nearest pole
Limitations
limited to use near the Standard Parallels
Polar Stereo
Parallels Meridians Scale Shapes Great circle Rhumb line
Properties
Parallels: concentric, unequally spaced circles, concave to nearer pole
Meridians: straight lines, converging at the pole
Scale: expands equally in all directions away from the pole
Shapes: correct around the point of tangency, distorted elsewhere
Great circle: approximately straight lines in polar region
Rhumb Line: concave to the nearer pole
Limitations
Unsed in high latitudes only (i.e. 45º to 90º)
Tranverse mercator
Standard cylindrical projection
Line of tangency touches both poles and follows a meridian/anti-meridian
Can spin cylinder around earth to determine which meridian will be line of tangency
Oblique mercator
Standard cylindrical projection
Line of tangency is between any two points
Used to create strip map
Points along the strip map retain all the advantages of the Mercator (at the equator)
Plotting charts used in the CF
GNC
JNC
ONC
WAC
GNC Lambert conformal Tranverse Mercator 1:5 000 000 JNC Lambert conformal 1:2 000 000 Main chart used in the later part of phase 1 ONC WAC Lambert Conformal 1:1 000 000 GPH 206: enroute low altitude charts GPH 207: enroute high altitude charts
