Depending on the jars you have on your CLASSPATH a range of authorities are available to define a coordinate. is_projected # True crs3857. 66"S. Now you'll need to reproject your data to the proper UTM zone. Transform Get position on a map. 06°N. Cadastre, engineering survey, topographic mapping (large scale). is_geographic # TrueDetailed design will require use of appropriate low-distortion local projected and vertical CRSs. addOptions({ sphericalMercator: true, projection: new OpenLayers. coordinates are in decimal degrees (lat, lon)). The original view (EPSG:3857) was following: After changing to CRS to. length >>> 1. EPSG:2526 Projected coordinate system for Belarus, Moldova, Russian Federation and Ukraine - onshore between 28°30'E and 31°30'E. pixel_size_x, pixel_size_y = dataset. You must reproject your data into EPSG:4326 for getting degrees in WGS84. e. Horizontal Coordinates: WGS84 [EPSG: 4326] Vertical Coordinates: WGS84 (EGM96 GEOID) [EPSG: 5171] Units: meter Data Selection Coordinates: Manually enter selection coordinates (in the horizontal coordinate system listed above) X min = Y min = X max = Y max = X min = Y min = X max = Y max = Validate coordinates and estimate area. e. 2 364078 4109926 (corner) M1 1. Custom, user-created CRSs are stored in a user CRS database. “EPSG Geodetic Parameter Dataset is a collection of definitions of coordinate reference systems and coordinate transformations which may be global, regional, national or local in application”. Left: Unprojected (Longitude/Latitude) using World Geodetic System 1984 Datum (WGS84) (EPSG = 4326) Right: USA Contiguous Albers Equal Area Conic, USGS (EPSG = 5070. So if I tell the library I want a buffer with a distance of 5 it will give me back a buffer with a radius of 5 degrees around my point. To convert a single coordinate. EPSG:2438 Projected coordinate system for China - onshore between 121°30'E and 124°30'E. 86666667mCoordinate Conversions. If you want meters, you'd need a projected coordinate system. Coordinates on a map - pick GPS lat & long or coordinates in a projection system. Powered by EPSG database 10. I would like to create 100 meters circle buffers in a UTM projection from a point table whose SRID is EPSG:4326 and keeping the id column. It’s often good practice to specifiy output extents, even for a global map. e. decode("EPSG:4326"); The example above assumes you have gt-epsg-hsql jar on your CLASSPATH. Isle of Man onshore. From what I read, to change the unit from degrees to meters I need to change my CRS. I want to use coordinates in degrees with EPSG:4326 so I initilize layer with: base_layer. Djibouti. By default the layer use EPSG:900913 and the coordinates are in meters. Replaced by Xian 1980 / 3-degree Gauss-Kruger CM 117E (code 2384). Cadastre, engineering survey, topographic mapping (large scale). I want to know the pixel size of my raster. Features that cannot be transformed are returned as empty geometries. Projection('EPSG:4326')}, true);For the second method, we create a transformer from a pyproj. Not used offshore in. Hungary, Poland and Slovakia - east of 22°30'E. select * from users where st_dwithin (location, st_setsrid (st_point (126. Setting projIn is harder, because your netCDF file defines its coordinate system with a WKT string, which (I'm pretty sure) can't be read directly by proj4 or pyproj. EPSG:3338 Projected coordinate system for United States (USA) - Alaska. EPSG:32611 Projected coordinate system for Between 120°W and 114°W, northern hemisphere between equator and 84°N, onshore and offshore. Transform coordinates for position on a map - converting latitude / longitude degrees From MapTiler Team. EPSG:2413 Projected coordinate system for China - onshore between 109°30'E and 112°30'E. EPSG:1840 Transformation for Qatar - onshore. It is distributed in three ways: • the . res 9. 8589506) Lon(2. I'm trying to convert a dataset that has projection parameters in meters to lat/long coordinates. Cadastre, engineering survey, topographic mapping (large scale). geometry import shape. ‘EPSG:4326’, which has the following alias ‘WGS84’ ‘EPSG:4269’ ‘EPSG:3857’, which has the following aliases ‘EPSG:3785’ ‘GOOGLE’ ‘EPSG:900913’ ‘EPSG:102113’ Defined projections can also be accessed through the proj4. Ask Question Asked 5 years, 8 months ago. 347945557 are not that. Modified 5 years, 8 months ago. “epsg:4326”) An EPSG integer code (i. Changing the projection of the map to EPSG:4326 and then saving the layer as CSV worked. Starting with GDAL 3. 06) Lon(253457. Downloading Landsat scenes. It looks like this: +init=epsg:4121 +proj=longlat +ellps=GRS80 +datum=GGRS87. 4 strings. tif reprojected. Spatial referencing. It means "forget about the fact that geojson files are implicitly in EPSG:4326, I'm very sure my input data is in epsg:3857". Error: creation of data source failed (OGR error:Failed to create directory . 575)'); Then I inspected the result in PGAdmin. 722279472, 6765816. You can determine the zone by adding 183 degrees to longitude, dividing by 6 and rounding (or adding 186 and truncating after division). e. 1 Introduction. Reproject Map. Engineering survey, topographic mapping. 4142135623730951. Just cast to geography within the buffer request. Share on: T Q. EPSG:4326 . 10 20,026,376. What you can do (besides using geography type) is projecting your data into the "better" CRS than EPSG:4326 (i. Therefore, the length attribute is expressed in the same unit of coordinates of your linestring, i. “EPSG Geodetic Parameter Dataset is a collection of definitions of coordinate reference systems and coordinate transformations which may be global, regional, national or local in application”. Zoom to a scale of 1:5 000 000 again, as before. Cadastre, engineering survey, topographic mapping (large scale). Area of use: North America - onshore and. Cadastre, engineering survey, topographic mapping (large scale). The EPSG:4326 version has pixels which are square in degrees Pixel Size = (0. I am quite a bit confused for example if, at least in practice, EPSG:4326 is equivalent to Plate Carrée equirectangular projection. Cadastre, engineering survey, topographic mapping (large scale). The points and line string where in "epsg=4326" which I am assuming is latitude and longitude. From the doc I know that res returns the (width, height) of pixels in the units of its coordinate reference system. Pan around the map. I was able to get the distance below. “EPSG Geodetic Parameter Dataset is a collection of definitions of coordinate reference systems and coordinate transformations which may be global, regional, national or local in application”. Now I have another shapefile(s) and I look at the shapefile. Here is my code, if you interested. I want to know the pixel size of my raster. UTM Zones are six degrees wide. The layer configs in Geoserver: native srs -. 8. Projection(‘EPSG:3857’), and the desProj should be OpenLayers. Also found with truncated false easting - see Beijing 1954 / 3-degree Gauss-Kruger CM 114E (code 2435). To avoid terminological confusion: the named "WGS84" is a CRS (coordinate reference system), so synonyms and human-readable abbreviation for urn:ogc:def:crs:EPSG::4326. After googling I know that degrees is my unit. referencing. Re-projecting data to North/South Pole. it seems it required to be cast twice: INSERT INTO buffers SELECT id_points, CAST (ST_Buffer (CAST (points. The confusion arise because Google Map shows (SRID) 900913 coordinates as long/lat degrees when they are actually easting/northing meters. EPSG:2414 Projected coordinate system for China - onshore between 112°30'E and 115°30'E. As defuneste mentions in their answer, 3857 is in meters and 4326 is in degrees, so the intersection didn't work. 889635,. Enter Meters: or Arc-Seconds: Enter Latitude: m km arc-seconds arc-minutes degrees Calculate Meters Calculate Arc-Seconds. WGS84 (EPSG 4326) is a geographic coordinate system with Lat/long coordinates in degree. divide bu 10**6 if you want m^2. R = 6378137 x = R * longitude y = R * ln(tan(pi/4 + latitude/2)) I'm unable to find corresponding functions for EPSG:3395, the so-called World Mercator projection. right-click on layer and select Save As. will return degrees. An authority string (i. 8589506) Lon(2. For comparison, I included a similar conversion from. EPSG:6933 has meters as unit epsg. Change the CRS of the DEM layer. gdaltransform -s_srs EPSG:4326+5773 -t_srs EPSG:4979 Enter X Y [Z [T]] values separated by space, and press Return. This means that the combination of GEOMETRY and EPSG:4326 is pretty much useless if you want to work with distances. csv with the desired CRS; Save the . 78. Also found with truncated false easting - see Beijing 1954 / 3-degree Gauss-Kruger CM 132E (code 2441). I add the layer world map (EPSG:4326 – WGS 84 by default) by taping “world” in the coordinate box in the middle bottom, I also add Open street map (EPSG:3857 – WGS 84 / Pseudo-Mercator by default) from. Looking into the proprieties of the layer indicates to me the CRS is EPSG:4326. 78098m, dY=-283. 555479), 5186), 1) This query gives me 32792923 rows which is all data in the table. 1. (meters, feet). I have tried this set of steps several times. I'm having a bit of trouble with projecting a DataFrame in GeoPandas from EPSG:4326 to EPSG:3857 in a notebook. Generally, a data distributor can set up CRS parameters as he wants to. But how do I directly pass meters as 3rd parameter. 37477m, dZ=+21. EPSG:2641 Projected coordinate system for Russian Federation - Kaliningrad - onshore between 19°30'E and 22°30'E. This elevation is stated in meters. I have reprojected to UTM EPSG: 32611 for both. 0 was released March 8th 2019. Even though there is an answer to my question How to create an accurate buffer of 5 miles around a coordinate in python?, but I can not represent it. Raw. The units are degrees. Truncated form of Pulkovo 1995 / 3-degree Gauss-Kruger zone 11 (code 2645). Spread the love. EPSG:5270 Projected coordinate system for Türkiye (Turkey) - between 28°30'E and 31°30'E, onshore. 62)Select WGS 84 / NSIDC EASE-Grid 2. Replaced by Xian 1980 / 3-degree Gauss-Kruger zone 40 (code 2364). Then the target SRS, and the destination and source filenames. coordinates are in decimal degrees (lat, lon)). shp as layer to the current project. I don't know why it's changing only one axis. ops import transform. First you need to reproject the GeoDataFrame to a different CRS which units is either meter or feet, and then measure the area using areaattribute. 0219772557337 0. The default CRS is set to EPSG:4326 – WGS 84, for both layer and the project (checked in bottom right), and unit is thus in degrees. Is there any solution to change the unit from degrees to meters for a global map? I'd be thankful for your help. To convert a set of coordinates like your example: 616928 6877084 621751 6877314 614317 6871645 588506 6883397 570571 6886266. EPSG:4326. Data should not be permitted to exceed 3-4 degrees into neighboring zones; if it does, UTM is the wrong projection, and you should use a conic (e. now both my shapefile and the project are in EPSG:4326, so unprojected: Here the rough measurement of my shapefile, with the. 9982 24. Replaced by Xian 1980 / 3-degree Gauss-Kruger zone 38 (code 2362). 39 20,048,966. Pixel. transform(epsg28992, wgs84,x,y) When I reverse and enter these coordinates in google maps they give me correct locations. Thus, when you run ST_Buffer on a EPSG:4326 geometry, the output is given in degrees of lat/lon. I don't know, only you will know which actual Coordinate reference systems you have, and want to convert into, but EPSG:4326 is a degrees latitude/longitude CRS so you should expect the first value to be +/- 90 and second value +/-180, and your values 6133089. In fact: >>> from shapely. So if you want a 500 meter buffer. The locations are from Portugal, so I picked up the "right" crs here:. (This is not the same as. Second polygon data: 100% polygon data in EPSG:4326. Transformation defines QND95. 001° of longitude. Vector(new OpenLayers. EPSG:2414 Projected coordinate system for China - onshore between 112°30'E and 115°30'E. Axes: northing, easting (X,Y). Transforms using the pipeline= argument may fail if there is ambiguity in the axis order of the specified coordinate reference system; if you need the traditional GIS order, use "OGC:CRS84", not "EPSG:4326". 0, the axis order mandated by the authority defining a CRS is by default honoured by the OGRCoordinateTransformation class, and always exported in WKT1. Sorry for the confusion, I'll edit the post. A slight confusion might come out of the fact that both 4326 and 3857 are in degrees, so the "right & proper" approach should in theory be: streets_import %>% st. EPSG:2207 Projected coordinate system for Türkiye (Turkey) - between 28°30'E and 31°30'E, onshore. 0 5572242. Cadastre, engineering survey, topographic mapping (large scale). 8. EPSG:4258 - ETRS89. Calculate length and use Tester transformer. In the case of EPSG:4326, coordinates are latitudes and longitues (i. 345' S becomes here -10° 1' 2. Zone width 3 degrees. This is quite exact. EPSG-number 4326 that we have here belongs to the WGS84 coordinate system (i. Second polygon data: 100% polygon data in EPSG:4326. Also found with truncated false easting - see Pulkovo 1942 / 3-degree Gauss-Kruger CM 63E (code 2596). 15. You have to provide the parameters explicitly, as shown here. 0174532925199433,ID["EPSG",9122]], Because the last one is not projected it does not have lengthunit. EPSG:4258 - ETRS89. EPSG:2607 Projected coordinate system for Russian Federation - onshore between 91°30'E and 94°30'E. I have used the Distance() function, but I'm getting some values and I couldn't identify the unit of those values. Sep 17, 2021 at 6:19. EPSG code 4326 that we have here, belongs to the WGS84 coordinate system (i. So the correct transformed coordinate would be: (56. And this is the query : > select * from theuser where ST_DWithin (point , ST_GeomFromText ('POINT (120. Proj (init='epsg:4326') The pyproj library can build a Proj object from an EPSG code. gdalwarp -s_srs epsg:4326 -t_srs epsg:3857 -te -20037508. Transforming EPSG:25831 to EPSG:4326 in Decimal Degrees format. So that is fine. ProjCRS sometimes found in metric form: 1 Gold Coast foot = 0. Convert coordinates from EPSG 4326 to EPSG 28992 in PostGIS. We were using Geotools library for mulitiple backend implementations. The JRC Monthly Water History dataset is an image that uses a single coordinate reference system (CRS) of EPSG:4326, and does not use the same CRS as Landsat images (which use a collection of UTM. It conforms to ISO 19111:2007 1– Spatial referencing by coordinates. 15. Coordinate conversions can be done conveniently using pyproj. 10. A four page cheat sheet about coordinate reference systems (CRSs), including projections, datums, and coordinate systems, and the use of these in R. Search Map Transform About +-q. ここで、組織は「epsg」や「ignf」などの組織名であり、コードは特定のcrsに関連付けられた一意の番号です。 たとえば、一般的なWGS 84緯度/経度CRSは識別子「EPSG：4326」で知られており、Webマッピング標準CRSは「EPSG：3857」です。EPSG:2232 Projected coordinate system for United States (USA) - Colorado - counties Arapahoe; Chaffee; Cheyenne; Clear Creek; Delta; Denver; Douglas; Eagle; El Paso; Elbert; Fremont; Garfield; Gunnison; Jefferson; Kit Carson; Lake; Lincoln; Mesa; Park; Pitkin; Summit; Teller. 32 to covert to km). Method: Position Vector transformation (geog2D domain) Remarks: Transformation defines QND95. EPSG:2602 Projected coordinate system for Kazakhstan, Kyrgyzstan and Russian Federation onshore - between 76°30'E and 79°30'E. I'm trying to convert a dataset that has projection parameters in meters to lat/long coordinates. After researching online and on stack exchange, I came up with a code. the bounds. EPSG:6425 Projected coordinate system for United States (USA) - California - counties Imperial; Orange; Riverside; San Diego. 972246695723605e-07. That's why you need to do an spTransform. WGS 84) is not a projection. EPSG:2703 Projected coordinate system for Russian Federation - onshore between 31°30'E and 34°30'E. You can use the search on the site to find an EPSG code. How it can be, if the range of these coordinates is. Create Vector Grid in Meters with EPSG:3857. Any formal standard CRS is composed by ellipsoid parametrized model reference + datum reference. 6. Replaced by Xian 1980 / 3-degree Gauss-Kruger zone 37 (code 2361). Cadastre, engineering survey, topographic mapping (large scale). ) from a spatial object in R. For example EPSG:4326 is using degrees as units while EPSG:3857 is using meters. The ST_Distance / ST_DWithin /etc. “epsg:4326”) An EPSG integer code (i. 3. Is there any solution to change the unit from degrees to meters for a global map?I'd be thankful for your help. WGS 84 - WGS84 - World Geodetic System 1984, used in GPS - EPSG:4326. “EPSG Geodetic Parameter Dataset is a collection of definitions of coordinate reference systems and coordinate transformations which may be global, regional, national or local in application”. Just wondering if if there is a way to change the buffer unit to meters but keep using EPSG 4326 as then all my layers seem to be at the right scale. STSrid=4326; But it doesn't work either. Use case. FIONA: from fiona. CRS; CoordinateReferenceSystem sourceCRS = CRS. The following example converts the station coordinates of two German stations to the regionally used Gauß-Krüger system. Scope: Cadastre, engineering survey, topographic mapping (large and medium scale). The simplest way to transform coordinates in Python is pyproj, i. But I want to use metres. Russian Federation - onshore. CRS. Only on top of the Equator one degree is as long in both directions. 4 I have a project with two point layers (in WGS84). Also used offshore by State Geological Surveys. We are developing Geographical Information System for Korean company. Since the WGS84 Reference System is not projected, it uses geographical coordinates (lat and long) which are expressed in degrees. Porting any of those code fragments to Objective-C or Swift. I am a GIS beginner, and I have a question about how to get the distance between two points in meters instead of decimal degree. Only on top of the Equator one degree is as long in both directions. WGS84 (EPSG: 4326) ## Commonly used by organizations that provide GIS data for the entire globe or many countries. Specifically, a square of 0. WGS 84 - WGS84 - World Geodetic System 1984, used in GPS - EPSG:4326 I have a global map with CRS WGS84-EPSG:4326 and I want to calculate the area of my polygons. 408917;37. )When dealing with coordinates systems in Python with fiona and osgeo, there seem to be a lot of ways to define a coordinate system by importing/exporting different crs formats , for example:. The reason it's a bad idea (usually) to buffer in degrees is that your buffer width/length will not be the same everywhere as the length of a degree of longitude shrinks towards the poles, or put another way, 2 degrees longitude is a much smaller length in Alaska than at the equator. For 4326 (for example), it's the meter. Share Tour Start here for a quick overview of the site Help Center Detailed answers to any questions you might have All points are stored with SRID=4326. See section Custom Coordinate Reference System for information on managing your custom coordinate reference. Hungary - west of 16°30'E. Introduced in 2000 as an alternative to CRS code 31300 to avoid the special projection method LCC (2SP Belgium) (code 9803). Also found with truncated false easting - see Beijing 1954 / 3-degree Gauss-Kruger CM 114E (code 2435). This approximation ignores the ~2. However, this value decreases as you move toward the poles due to the Earth’s curvature. 15. Geographical coordinates are not meant for area and distance calculations. After looking up the EPSG codes of source and target coordinate system, the conversion can be done in just a few lines of code. Mexico. Cadastre, engineering survey, topographic mapping (large scale). Truncated form of Pulkovo 1942 / 3-degree Gauss-Kruger zone 26 (code 2542). The EPSG Dataset is maintained by the IOGP Geomatics Committee’s Geodesy Subcommittee. However, there are plenty of projected coordinate reference systems (CRS) that use the WGS84 datum with metres as the horizontal units. Default is cyl . Questions tagged [wgs84] WGS 84 (that spelling) is the name of an ellipsoid (EPSG::7030), the name of a geodetic coordinate reference system (EPSG::4326), and the alias of a datum (EPSG::6326), official name World Geodetic System 1984. Also found with truncated false easting - see Pulkovo 1942 / 3-degree Gauss-Kruger CM 171W (code 2639). 0, GDAL 3. In our Postgres/Postgis database we store polygons in a column defined as lonlat/EPSG:4326, as it may contain data from anywhere in the world. buffer() takes arguments in degree format only, how can I use meters format? Do I. So clearly, PostGIS (or pgAdmin) expect my data as long/lat, instead of lat/long. Engineering survey, topographic mapping. I need to create vector grids with precise measurements in meters. A typical input is coordinates in meters and the name of an SRS which has meters as unit. There is no exact conversion to meters from 4326 degrees. Now, let's look at the geometry and geography types. EPSG:3332 Projected coordinate system for Bulgaria and Romania - between 22°30'E and 25°30'E. Data should not be permitted to exceed 3-4 degrees into neighboring zones; if it does, UTM is the wrong projection, and you should use a conic (e. 384 km, it will only create a grid square size of 10 km. The coordinates are being transformed from EPSG:3857 (WGS 84 / Pseudo-Mercator, units = meters) to EPSG:4326 (WGS 84 / geographic, units = degrees) For example, here is the coordinates from your screenshot transformed from EPSG:4326 to EPSG:3857. I have EPSG:4326 data for polygons and would like to calculate the intersection of these polygons in square meters. EPSG:4326, also known as the WGS84 projection (because it’s based on WGS84’s ellipsoid), is a coordinate system used in Google Earth and GSP systems. e. 0044996 degrees@DmytroGokun thanks for the feedback. EPSG:31467 Projected coordinate system for Germany - former West Germany onshore between 7°30'E and 10°30'E - states of Baden-Wurtemberg, Bayern, Bremen, Hamberg, Hessen, Niedersachsen, Nordrhein-Westfalen, Rhineland-Pfalz, Schleswig-Holstein. I have two points on a EPSG:4326 layer. To avoid terminological confusion: the named "WGS84" is a CRS (coordinate reference system), so synonyms and human-readable abbreviation for urn:ogc:def:crs:EPSG::4326. EPSG:32637 Projected coordinate system for Between 36°E and 42°E, northern hemisphere between equator and 84°N, onshore and offshore. from_user_input(): CRS WKT string. EPSG:3857. ShareEPSG:4326 is measured in degrees, but EPSG:32612 is measured in metres. For cadastral purposes, replaces Kertau 1968 / Singapore Grid (CRS code 24500) from August 2004. 25 The fact that the units of the CRS are meters (rather than degrees) tells us that this is a projected CRS: st_is_longlat(london_proj) now returns FALSE and. We have a requirement to calculate the surface area (i. Hi @MichaelDelgado, you are correct I want Lat/ Lon in degrees, so it will be EPSG:4326 is WGS84 (lat/lons on a geoid). S. While the . 6374,4826473. However I have problem now with conversion from. Depending on the jars you have on your CLASSPATH a range of authorities are available to define a coordinate. The coordinates you posted are not the same coordinates between the two, you would have to convert the geometry to a 3857 geometry, or convert from the decimal degrees to meters. g. Replaces CH1903/LV03 (code 21781). 956 m. 86424016952515 36. Select Vector > Geoprocessing Tools > Buffers > set buffer distance as. . To illustrate that: let's say you have coordinates in EPSG:4326 (WGS84, GPS coordinates) 0° E, 51. 75 4109976. ). From epsg. EPSG:2436 Projected coordinate system for China - onshore between 115°30'E and 118°30'E. i created a point layers of store locations and customers in Florida by given coordinates (WGS 84 EPSG: 4326). Cadastre, engineering survey, topographic mapping (large and medium scale). The method is fully documented at Geomatics Guidance Note No 7, part 2 There's an mathematical example at page 40 where you can use to cross-reference your code. When I properly transformed the 4326 projection then my intersection started working properly. Coordinate system Change. EPSG:9354 Projected coordinate system for Southern hemisphere - south of 50°S onshore and offshore, including Antarctica. GeoPandas can accept anything accepted by pyproj. Also found with truncated false easting - see Beijing 1954 / 3-degree Gauss-Kruger CM 114E (code 2435). select st_distance (st_setsrid (st_makepoint (126. (init='epsg:4326') outProj = Proj(init='epsg:3857') x1,y1. So maybe this version does a bit better job for fitting and cropping the result to valid area of EPSG:3857 but not at all perfect. One solution is to use the GEOGRAPHY data type. Area of use: South Africa - east of 32°E. UTM Zones are six degrees wide. EPSG Projection 4326 - WGS 84 Home | Upload Your Own | List user-contributed references | List all references Previous: EPSG:4324: WGS 72BE | Next: EPSG:4327: WGS 84 (geographic 3D)As you see from the brackets, the EPSG:9001 is only valid for the UNIT variable. May 20, 2013 at 20:53. Case study to illustrate assigning CRS vs. The standard is. Transforms using the pipeline= argument may fail if there is ambiguity in the axis order of the specified coordinate reference system; if you need the traditional GIS order, use "OGC:CRS84", not "EPSG:4326". Truncated form of Pulkovo 1942 / 3-degree Gauss-Kruger zone 31 (code 2547). PROJ or PROJ. g. EPSG:32616 Projected coordinate system for Between 90°W and 84°W, northern hemisphere between equator and 84°N, onshore and offshore. 1 degree° = 60 arc minutes ' 1 arc minute ' = 60 arc seconds '' 1 arc second '' at equatorial sea level = 1852m/60 = 30. EPSG:2415 Projected coordinate system for China - onshore between 115°30'E and 118°30'E. Geometry assumes a flat map, geography takes in. And this is the query : > select * from theuser where ST_DWithin (point , ST_GeomFromText ('POINT (120. And the conversion depends on the latitude of the points, as 1 degree at the equator will be less meters than 1 degree at high latitudes. Quick way of telling what SRID your lat/lon is in: Look at how big the number & the precision. 0, GDAL 3. In this following example we will be computing straight line distances between Penzance and London in PostGIS with different projections to emphasize the importance of choosing wisely. As a rough estimate, at the equator, 1 degree of latitude is approximately 111 kilometers, which is roughly equivalent to 111,000 meters. Cadastre, engineering survey, topographic mapping (large scale).