![]() You can see the coordinate value for a place on a map in the ArcMap status bar, at the bottom right of the application. ![]() This is not an exhaustive list of the delimiters and hemisphere indicators that are used in each system.ĪrcGIS 10 can convert coordinates expressed in each of these systems into the others, and provides ways of displaying and accepting coordinate input in most of them. This table shows the coordinate representation for Philadelphia, Pennsylvania in the US (75° 9’ 18.382” West longitude by 39° 59’ 0.637” North latitude) in each of these systems. Two less frequently used systems, the Global Area Reference System ( GARS) and Geographic Reference System ( GEOREF), divide the world into polygonal areas based on different sets of nested grids and encode locations as a string of grid ID values.Įach of these ways of representing a location results in different strings of characters with a variety of formats. For USNG and MGRS the numeric values of the northing and easting can vary from 1 to 5 digits, depending on the precision of the location (they must both use the same number of digits) and then the values are concatenated. Within the grids, point locations are specified by their position East and North the zone origin or the southeast corner of the cell. Gridded systems, like Universal Transverse Mercator ( UTM), United States National Grid ( USNG), Military Grid Reference System ( MGRS) divide the world into zones which are projected and then overlaid with one or more grids. Another common method is to use a projected coordinate system and X and Y coordinate pairs, that is, two sets of numbers in a planar Cartesian system. These Geographic coordinates may be expressed in several different notations, including Decimal Degrees (DD), Degrees Decimal Minutes (DDM), and Degrees Minutes and Seconds (DMS). The formula for converting Degree Minutes and Seconds to Decimal Degrees is discussed in the ArcGIS 10 Help. One of the most common uses angular latitude and longitude coordinates to specify the location of a point. ![]() Mor constants, extracted from the function:Ĭonst k0 = 0.9996 // scale on central meridianĬonst e = Math.sqrt(1 - (b/a)*(b/a)) // eccentricityĬonst e0 = e / Math.There are many ways of representing locations. Symbols as used in USGS PP 1395: Map Projections - A Working ManualĬonst a = DatumEqRad // equatorial radius (meters)Ĭonst f = 1 / DatumFlat // polar flatteningĬonst drad = Math.PI / 180 // convert degrees to radians Note that this example will give you the coordinates in decimal (which is what most things accept anyways), but you can convert them to degrees/minutes/seconds quite easily (look near the end of the original function). I cleaned up the JavaScript a little since the language has evolved a lot since the original code was written, but the idea is still the same. Since all you need is Zone 34N, you can simplify that a lot by inlining some of the constants, but to make this answer more generic, here is a complete solution that works with any reference system. The JavaScript is inlined in the page source, as Ahmed mentions. The website in GIS's answer is no longer available at the original URL, but you can still have a look on. In other words I want to do what the converter I does. However, let's say that all I want is to convert from UTM to GCS WGS84. ![]() However I would like to know the formula for doing this, since I want to use it in my code. ![]() I want to convert these data in latitude and longitude so that I can draw a simple map in my program. My development environment uses a simple XY system. The SQL Server uses WGS 84 / UTM zone 34N to represent the polygons. I have the data stored in SQL Server (the points of the polygon). My problem is I want to represent some properties (polygons) in some kind of a map (image). Can anyone help me with the formula for converting from WGS 84 / UTM Zone 34N to World Geodetic System? ![]()
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