Understanding Map Projections

More documents

Recommendations

Info

LAMBERT CONFORMAL CONIC Area Minimal distortion near the standard parallels. Areal scale is reduced between standard parallels and increased beyond them. Direction Local angles are accurate throughout because of conformality. Distance Correct scale along the standard parallels. The scale is reduced between the parallels and increased beyond them. The central meridian is 125° E. The first and second standard parallels are 32° S and 7° N, while the latitude of origin is 32° S. DESCRIPTION This projection is one of the best for middle latitudes. It is similar to the Albers Conic Equal Area projection except that Lambert Conformal Conic portrays shape more accurately than area. The State Plane Coordinate System uses this projection for all east–west zones. PROJECTION METHOD Conic projection normally based on two standard parallels, making it a secant projection. The latitude spacing increases beyond the standard parallels. This is the only common conic projection that represents the poles as a single point. LIMITATIONS Best for regions predominantly east–west in extent and located in the middle north or south latitudes. Total latitude range should not exceed 35 degrees. USES AND APPLICATIONS SPCS for all east–west zones. USGS 7½-minute quad sheets to match the State Plane Coordinate System. Used for many new USGS maps created after 1957. It replaced the Polyconic projection. Continental United States: standard parallels, 33° and 45° N. Entire United States: standard parallels, 37° and 65° N. LINES OF CONTACT The two standard parallels. LINEAR GRATICULES All meridians. PROPERTIES Shape All graticular intersections are 90 degrees. Small shapes are maintained. 66 • Understanding Map Projections
LOCAL CARTESIAN PROJECTION DESCRIPTION This is a specialized map projection that does not take into account the curvature of the earth. It’s designed for very large-scale mapping applications. PROJECTION METHOD The coordinates of the center of the area of interest define the origin of the local coordinate system. The plane is tangent to the spheroid at that point, and the differences in z values are negligible between corresponding points on the spheroid and the plane. Because the differences in z values are ignored, distortions will greatly increase beyond roughly one degree from the origin. USES AND APPLICATIONS Large-scale mapping. Should not be used for areas greater than one degree from the origin. Supported map projections• 67
Page 1 and 2:
Understanding Map Projections GIS b
Page 3 and 4:
Contents CHAPTER 1: GEOGRAPHIC COOR
Page 5:
State Plane Coordinate System .....
Page 8 and 9:
GEOGRAPHIC COORDINATE SYSTEMS A geo
Page 10 and 11:
SPHEROIDS AND SPHERES The shape and
Page 12 and 13:
DATUMS While a spheroid approximate
Page 15 and 16:
2 Projected coordinate systems Proj
Page 17 and 18:
WHAT IS A MAP PROJECTION? Whether y
Page 19 and 20:
PROJECTION TYPES Because maps are f
Page 21 and 22: maintained for both small-scale and
Page 23 and 24: Planar projections Planar projectio
Page 25 and 26: OTHER PROJECTIONS The projections d
Page 27: The four parameters above are used
Page 30 and 31: GEOGRAPHIC TRANSFORMATION METHODS M
Page 32 and 33: Unless explicitly stated, it’s im
Page 34 and 35: National Transformation version 2 L
Page 36 and 37: LIST OF SUPPORTED MAP PROJECTIONS A
Page 38 and 39: Loximuthal McBryde-Thomas Flat-Pola
Page 40 and 41: AITOFF USES AND APPLICATIONS Develo
Page 42 and 43: ALASKA SERIES E LIMITATIONS This pr
Page 44 and 45: AZIMUTHAL EQUIDISTANT Area Distorti
Page 46 and 47: BIPOLAR OBLIQUE CONFORMAL CONIC DES
Page 48 and 49: CASSINI-SOLDNER Area No distortion
Page 50 and 51: CRASTER PARABOLIC Distance Scale is
Page 52 and 53: DOUBLE STEREOGRAPHIC Oblique aspect
Page 54 and 55: ECKERT II The central meridian is 1
Page 56 and 57: ECKERT IV parallels. Nearer the pol
Page 58 and 59: ECKERT VI central meridian. Scale i
Page 60 and 61: EQUIDISTANT CYLINDRICAL LINES OF CO
Page 62 and 63: GALL’S STEREOGRAPHIC Area Area is
Page 64 and 65: GEOCENTRIC COORDINATE SYSTEM Geogra
Page 66 and 67: GNOMONIC PROPERTIES Shape Increasin
Page 68 and 69: HAMMER-AITOFF LIMITATIONS Useful on
Page 70 and 71: KROVAK Direction Local angles are a
Page 74 and 75: LOXIMUTHAL Distance Scale is true a
Page 76 and 77: MERCATOR Greenland is only one-eigh
Page 78 and 79: MOLLWEIDE Distance Scale is true al
Page 80 and 81: ORTHOGRAPHIC PROPERTIES Shape Minim
Page 82 and 83: PLATE CARRÉE Direction North, sout
Page 84 and 85: POLYCONIC Direction Local angles ar
Page 86 and 87: RECTIFIED SKEWED ORTHOMORPHIC DESCR
Page 88 and 89: SIMPLE CONIC Equirectangular projec
Page 90 and 91: SPACE OBLIQUE MERCATOR DESCRIPTION
Page 92 and 93: Montana—The three zones for Monta
Page 94 and 95: TIMES LIMITATIONS Useful only for w
Page 96 and 97: 10,000,000 meters to ensure that al
Page 98 and 99: UNIVERSAL POLAR STEREOGRAPHIC Area
Page 100 and 101: VAN DER GRINTEN I Distance Scale al
Page 102 and 103: WINKEL I Distance Generally, scale
Page 104 and 105: WINKEL T RIPEL Distance Generally,
Page 107 and 108: Glossary angular units The unit of
Page 109 and 110: High Accuracy Reference Network A r
Page 111: UTM See Universal Transverse Mercat
Page 114 and 115: Eckert VI 52 ED 1950 6 Ellipse 101
Page 116: Projections (continued) planar 17,
show all

Understanding Map Projections

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?