![]() ![]() While data may be maintained using the recommendations above, it is now acceptable common practice to publish GIS web services using Web Mercator Auxiliary Sphere (WGS84). Scale distortion of 15 parts in 10,000 (or a scale factor of 1.0015). UTM zone 18 extended to cover All of New York provides a maximum System provides scale distortions of less than 4 parts in 10,000 insideĪny zone. UTM zoneġ8 mathematically extended to cover the entire state provides a convenientĪnd appropriate continuous for mid to small scale mapping. Idaho is split into two UTM zones: Zone 11 (west of 114 W. Should be built on a continuous statewide coordinate system. Many federal entities maintain data in the Universal Transverse Mercator (UTM) projection. Sets including 1:24,000 scale quadrangles and digital orthophoto quadrangles Of less than one part in 10,000 within any one zone. The state plane coordinate system provides scale distortions Survey Feetįor data at scales smaller than 1:10,000: UTM Zone 18, MetersĪre most appropriate for large scale applications such as parcel and utility Coordinate Systems Recommendation:įor data at 1:10,000 scale and larger: State Plane, Meters or U.S. Note: the GRS-80 ellipsoid should be used with the NAD-83 datum.Īs of the date of this updated standard, the model to transform between ellipsoid coordinates and NAVD88 heights is GEOID 12B. This datum has several adjustments or realizations over the years, so data custodians should document which they are using. The Universal Transverse Mercator (UTM) system divides the world into a regular, nonoverlapping grid of quadrangles called zones. The intent is not to require data providers to convert old data to new coordinate systems, but rather to make clear a preferred set of standards which make sense and provide maximum utility for new technologies. Accurate documentation will be especially important during the transition to a new horizontal datum and vertical datum scheduled for 2022. Specifically, the intent is to minimize the number of datum and map projection/coordinate systems combinations in use and to encourage accurate documentation of the systems referenced by data coordinates. The intent of this standard is to minimize the effort required to use data collected from various sources in New York State. This is not intended to advise the practice of land surveying. The intended audience for this standard is the GIS practitioner community of New York throughout all sectors. The co-ordinates thus derived define a location within a UTM projection zone either north or south of the equator, but because the same co-ordinate system is repeated for each zone and hemisphere, it is necessary to additionally state the UTM longitudinal zone and either the hemisphere or latitudinal zone to define the location uniquely world-wide.The following recommendations were compiled by the Standards Work Group (now the Standards and Data Coordination Work Group), and have been approved by the Coordinating Body (now the Geospatial Advisory Council). ![]() Within each longitudinl zone the transverse mercator projection is used to give co-ordinates (eastings and northings) in metres.įor the eastings, the origin is defined as a point 500,000 metres west of the central meridian of each longitudinal zone, giving an easting of 500,000 metres at the central meridian.įor the northings in the northern hemisphere, the origin is defined as the equator.įor the northings in the southern hemisphere, the origin is defined as a point 10,000,000 metres south of the equator. For example, the southern end of South America is 19F. Each of these is 8 degrees south-north, apart from zone X which is 12 degrees south-north.Īreas are referenced by quoting the longitudinal zone number, followed by the latitudinal zone letter. Here is a convenient way to find the zone number for a particular longitude. There are 20 latitudinal zones spanning the latitudes 80°S to 84°N and denoted by the letters C to X, ommitting the letters I and O. The conterminous United States is within UTM zones 10 to 19. Each of these zones is 6 degrees wide, apart from a few exceptions around Norway and Svalbard. There are 60 longitudinal projection zones numbered 1 to 60 starting at 180°W. UTM Grid Zones of the World compiled by Alan Morton ![]()
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