Knowledge (XXG)

Horizontal position representation

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30: 535:, which makes longitude undefined at these points. Also near the poles the latitude/longitude grid is highly non-linear, and several errors may occur in calculations that are sufficiently accurate on other locations. 738:
When deciding which parameters to use for representing position in a specific application, there are several properties that should be considered. The following table gives a summary of what to consider.
649:-axis in the vertical direction. Hence (three dimensional) position vectors relative to this coordinate frame will have two horizontal and one vertical parameter. The axes are typically selected as 672:
For small areas a local coordinate system can be convenient for relative positioning, but with increasing (horizontal) distances, errors will increase and repositioning of the
550:, and hence specific program code must often be written to handle this. An example of the consequences of omitting such code is the crash of the navigation systems of twelve 454:. There are also several applications where only the horizontal position is of interest, this might e.g. be the case for ships and ground vehicles/cars. It is a type of 869: 716: 712: 707: 470: 389: 527:
However, latitude and longitude should be used with care in mathematical expressions (including calculations in computer programs). The main reason is the
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There are several options for horizontal position representations, each with different properties which makes them appropriate for different applications.
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UTM is widely used, and the coordinates approximately corresponds to meters north and east. However, as a set of map-projections it has inherent
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North and east directions are undefined at the Poles, and near the Poles these directions may change significantly within the area of interest
337: 524:. The parameters are intuitive and well known, and are thus suited for communicating a position to humans, e.g. using a position plot. 417: 859:
Errors increase with increasing horizontal distance from the tangent point (which may require repositioning of the tangent point)
680:, and near the Poles these directions might have significant errors (here the linearization is valid only in a very small area). 477: 203: 957: 219: 1033: 455: 612:-vector is well-suited for mathematical calculations, e.g. adding, subtracting, interpolating and averaging positions. 842: 645:
at a specified Earth-fixed position. The origin is often selected at the surface of the reference ellipsoid, with the
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Instead of one local Cartesian grid, that needs to be repositioned as the position of interest moves, a fixed set of
998: 182: 730:, and thus most calculations based on UTM will not be exact. The crossing of zones gives additional complexity. 480:, and thus two parameters are sufficient to uniquely describe such a position. However, similarly to the use of 812: 780: 578: 528: 489: 149: 619:-vector is inconvenient for communicating a position directly to humans and before showing a position plot, a 96: 432: 247: 267: 29: 856:
Can only be used for relative positioning (the tangent point must be represented by some other quantity)
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horizontal position representation that can replace latitude and longitude. Geometrically, it is a
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may be required. The alignment along the north and east directions is not possible at the
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Cartesian vectors in meters along the directions of north, east and down are obtained
720: 673: 658: 654: 492:, and thus three parameters are required for the horizontal position to avoid this. 481: 92: 727: 582: 551: 49: 984: 890: 763: 600:. It behaves the same at all Earth positions, and it holds the mathematical 521: 511: 466: 450:(height or depth) separately, and to use some other parameters to represent 128: 54: 802: 759: 715:
is one such system, dividing the Earth into 60 longitude zones (and with
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property. The vector formulation makes it possible to use standard 3D
773:
Parameters are easy to recognize by humans (well-suited for plotting)
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When carrying out several calculations within a limited area, a
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is a set of parameters used to express a position relative to a
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Efficient in equations/calculations since standard 3D
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The most common horizontal position representation is
488:, using only the minimum number of parameters gives 958:"A non-singular horizontal position representation" 831:
Inconvenient for communicating a position to humans
743:Comparison of horizontal position representations 900:Calculations get complex when crossing the zones 473:are common horizontal position representations. 882:One unit corresponds approximately to one meter 708:Universal Transverse Mercator coordinate system 554:fighter aircraft while crossing this meridian. 440:. When representing positions relative to the 411: 8: 444:, it is often most convenient to represent 971:(3). Cambridge University Press: 395–417. 657:, and thus this system can be viewed as a 418: 404: 385:Spatial Reference System Identifier (SRID) 380:International Terrestrial Reference System 17: 999:"Stealth fighters hit by software crash" 741: 948: 922:Rotation formalisms in three dimensions 824:All Earth positions are treated equally 20: 879:Approximate north and east directions 546:longitude, where the longitude has a 7: 486:formalism for representing rotations 243: 698:covering the Earth can be defined. 390:Universal Transverse Mercator (UTM) 352:European Terrestrial Ref. Sys. 1989 262:Ordnance Survey Great Britain 1936 228:Discrete Global Grid and Geocoding 119:Horizontal position representation 14: 621:conversion to latitude/longitude 538:Another problematic area is the 476:The horizontal position has two 178:Global Nav. Sat. Systems (GNSSs) 28: 789:Complex behavior near the Poles 342:N. American Vertical Datum 1988 627:Local flat Earth approximation 372:Internet link to a point 2010 302:Geodetic Reference System 1980 220:Quasi-Zenith Sat. Sys. (QZSS) 1: 1029:Geographic coordinate systems 362:Chinese obfuscated datum 2002 456:geographic coordinate system 312:Geographic point coord. 1983 843:Cartesian coordinate system 639:Cartesian coordinate system 272:Systema Koordinat 1942 goda 1050: 705: 687: 641:might be defined with the 630: 595:Earth centered earth fixed 564: 505: 499: 332:World Geodetic System 1984 985:10.1017/S0373463309990415 965:The Journal of Navigation 322:North American Datum 1983 292:South American Datum 1969 615:Using three parameters, 183:Global Pos. System (GPS) 150:Spatial reference system 585:which is normal to the 433:position representation 956:Gade, Kenneth (2010). 792:Discontinuity at the ± 496:Latitude and longitude 834:Uses three parameters 690:Grid reference system 684:Grid reference system 577:is a three parameter 506:Further information: 78:Geographical distance 927:Geodetic coordinates 502:Geodetic coordinates 252:Sea Level Datum 1929 104:Geodetic coordinates 1034:Geographic position 1001:. 27 February 2007. 977:2010JNav...63..395G 744: 633:Local tangent plane 587:reference ellipsoid 452:horizontal position 282:European Datum 1950 240:Standards (history) 140:Reference ellipsoid 88:Figure of the Earth 742: 478:degrees of freedom 160:Vertical positions 937:Plane coordinates 913: 912: 623:might be needed. 598:coordinate system 447:vertical position 428: 427: 376: 375: 155:Spatial relations 145:Satellite geodesy 100: 1041: 1003: 1002: 995: 989: 988: 962: 953: 745: 589:. The vector is 420: 413: 406: 244: 223: 215: 207: 199: 191: 131: 90: 32: 18: 1049: 1048: 1044: 1043: 1042: 1040: 1039: 1038: 1009: 1008: 1007: 1006: 997: 996: 992: 960: 955: 954: 950: 945: 932:Geodetic system 918: 907:are not covered 736: 710: 704: 696:map projections 692: 686: 651:North-East-Down 635: 629: 569: 563: 514: 504: 498: 438:reference frame 424: 395: 394: 241: 233: 232: 221: 213: 205: 197: 189: 173: 165: 164: 123: 73: 65: 64: 40: 12: 11: 5: 1047: 1045: 1037: 1036: 1031: 1026: 1021: 1011: 1010: 1005: 1004: 990: 947: 946: 944: 941: 940: 939: 934: 929: 924: 917: 914: 911: 910: 909: 908: 901: 898: 895:map projection 885: 884: 883: 880: 877: 872: 866: 865: 864: 863: 860: 857: 852: 851: 850: 845: 838: 837: 836: 835: 832: 827: 826: 825: 822: 819:vector algebra 815: 808: 799: 798: 797: 796: 790: 787: 776: 775: 774: 771: 766: 756: 755: 752: 749: 748:Representation 735: 732: 706:Main article: 703: 700: 688:Main article: 685: 682: 631:Main article: 628: 625: 606:vector algebra 565:Main article: 562: 556: 500:Main article: 497: 494: 426: 425: 423: 422: 415: 408: 400: 397: 396: 393: 392: 387: 382: 374: 373: 370: 364: 363: 360: 354: 353: 350: 344: 343: 340: 334: 333: 330: 324: 323: 320: 314: 313: 310: 304: 303: 300: 294: 293: 290: 284: 283: 280: 274: 273: 270: 264: 263: 260: 254: 253: 250: 242: 239: 238: 235: 234: 231: 230: 225: 217: 209: 201: 193: 185: 180: 174: 171: 170: 167: 166: 163: 162: 157: 152: 147: 142: 137: 135:Map projection 132: 121: 116: 111: 109:Geodetic datum 106: 101: 85: 80: 74: 71: 70: 67: 66: 63: 62: 57: 52: 47: 41: 38: 37: 34: 33: 25: 24: 13: 10: 9: 6: 4: 3: 2: 1046: 1035: 1032: 1030: 1027: 1025: 1022: 1020: 1017: 1016: 1014: 1000: 994: 991: 986: 982: 978: 974: 970: 966: 959: 952: 949: 942: 938: 935: 933: 930: 928: 925: 923: 920: 919: 915: 906: 905:Polar Regions 902: 899: 896: 892: 888: 887: 886: 881: 878: 875: 874: 873: 871: 868: 867: 861: 858: 855: 854: 853: 848: 847: 846: 844: 840: 839: 833: 830: 829: 828: 823: 820: 816: 814: 811: 810: 809: 807: 805: 801: 800: 795: 794:180° meridian 791: 788: 786: 782: 781:Singularities 779: 778: 777: 772: 769: 768: 767: 765: 761: 758: 757: 753: 750: 747: 746: 740: 733: 731: 729: 724: 722: 721:Polar regions 719:covering the 718: 714: 709: 701: 699: 697: 691: 683: 681: 679: 675: 674:tangent point 670: 668: 664: 660: 659:linearization 656: 655:East-North-Up 652: 648: 644: 640: 634: 626: 624: 622: 618: 613: 611: 607: 603: 599: 596: 592: 588: 584: 580: 576: 574: 568: 560: 557: 555: 553: 549: 548:discontinuity 545: 541: 536: 534: 530: 529:singularities 525: 523: 519: 513: 509: 503: 495: 493: 491: 490:singularities 487: 483: 479: 474: 472: 468: 464: 459: 457: 453: 449: 448: 443: 439: 435: 434: 421: 416: 414: 409: 407: 402: 401: 399: 398: 391: 388: 386: 383: 381: 378: 377: 371: 369: 366: 365: 361: 359: 356: 355: 351: 349: 346: 345: 341: 339: 336: 335: 331: 329: 326: 325: 321: 319: 316: 315: 311: 309: 306: 305: 301: 299: 296: 295: 291: 289: 286: 285: 281: 279: 276: 275: 271: 269: 266: 265: 261: 259: 256: 255: 251: 249: 246: 245: 237: 236: 229: 226: 224: 218: 216: 210: 208: 202: 200: 196:BeiDou (BDS) 194: 192: 186: 184: 181: 179: 176: 175: 169: 168: 161: 158: 156: 153: 151: 148: 146: 143: 141: 138: 136: 133: 130: 126: 122: 120: 117: 115: 112: 110: 107: 105: 102: 98: 97:circumference 94: 89: 86: 84: 81: 79: 76: 75: 69: 68: 61: 58: 56: 53: 51: 48: 46: 43: 42: 36: 35: 31: 27: 26: 23: 19: 16: 993: 968: 964: 951: 893:(due to the 803: 737: 725: 711: 693: 671: 646: 636: 616: 614: 609: 579:non-singular 572: 570: 558: 537: 526: 515: 482:Euler angles 475: 460: 451: 445: 431: 429: 172:Technologies 127: / 118: 39:Fundamentals 15: 876:Widely used 821:can be used 813:Nonsingular 770:Widely used 728:distortions 608:, and thus 583:unit vector 552:F-22 Raptor 50:Geodynamics 1019:Navigation 1013:Categories 943:References 891:distortion 734:Comparison 602:one-to-one 591:decomposed 889:Inherent 764:longitude 667:parallels 663:meridians 522:longitude 512:Longitude 467:longitude 129:Longitude 55:Geomatics 916:See also 760:Latitude 567:n-vector 540:meridian 518:latitude 508:Latitude 463:Latitude 308:ISO 6709 206:(Europe) 204:Galileo 190:(Russia) 188:GLONASS 125:Latitude 114:Geodesic 72:Concepts 1024:Geodesy 973:Bibcode 806:-vector 783:at the 661:of the 575:-vector 561:-vector 531:at the 368:Geo URI 338:NAVD 88 248:NGVD 29 222:(Japan) 214:(India) 198:(China) 60:History 45:Geodesy 22:Geodesy 841:Local 643:origin 593:in an 358:GCJ-02 348:ETRS89 328:WGS 84 318:NAD 83 298:GRS 80 258:OSGB36 212:NAVIC 93:radius 961:(PDF) 785:Poles 754:Cons 678:Poles 533:Poles 484:as a 442:Earth 288:SAD69 268:SK-42 83:Geoid 903:The 762:and 751:Pros 665:and 544:180° 542:at ± 520:and 510:and 469:and 278:ED50 95:and 981:doi 870:UTM 723:). 717:UPS 713:UTM 702:UTM 653:or 471:UTM 1015:: 979:. 969:63 967:. 963:. 669:. 458:. 430:A 987:. 983:: 975:: 804:n 647:z 617:n 610:n 573:n 559:n 465:/ 419:e 412:t 405:v 99:) 91:(

Index

Geodesy

Geodesy
Geodynamics
Geomatics
History
Geographical distance
Geoid
Figure of the Earth
radius
circumference
Geodetic coordinates
Geodetic datum
Geodesic
Horizontal position representation
Latitude
Longitude
Map projection
Reference ellipsoid
Satellite geodesy
Spatial reference system
Spatial relations
Vertical positions
Global Nav. Sat. Systems (GNSSs)
Global Pos. System (GPS)
GLONASS (Russia)
BeiDou (BDS) (China)
Galileo (Europe)
NAVIC (India)
Quasi-Zenith Sat. Sys. (QZSS) (Japan)

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