Questions tagged [datum]
The information connecting numerical coordinates to actual locations on the earth.
248
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Identifying the coordinate system in a set of Australian data
I have the following set of data.
Name
Easting
Northing
Point 1
7675
0576
Point 2
7758
0330
Point 3
7568
0864
I would like to know what coordinate system this data uses, to convert it to latitude ...
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autonavi / amap xyz tile layer appears shifted in OpenLayers (Chinese Web Mercator with GCJ-02 datum)
I am trying to add an xyz source tile layer to OpenLayers v8.1.
The source URI for the tiles is the Chinese autonavi / amap provider.
http://webrd0{1-4}.is.autonavi.com/appmaptile?lang=zh_cn&size=...
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Converting geodetic coordinates to ENU coordinates
I am trying to understand conversion from geodetic coordinates to ENU coordinates. As per this wikipedia page, its two step process: geodetic to ECEF coordinates and then ECEF coordinates to ENU ...
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Location from which QGIS reads datum transforms
I am trying to transform coordinates from the Adindan datum (EPSG:4201) to the WGS-1984 datum (EPSG:4326) using the transform Adindan to WGS 84 (6) (EPSG:1105).
But when I try to select it, QGIS only ...
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Vertical transformation of DEM from NAVD88 to CGVD2013 datums
I am attempting to recalculate a DEM raster from the vertical datum of NAVD88 to the 'new' Canadian vertical datum, which is CGVD2013. I've looked at a few similar questions but they only are geoidal ...
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53
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How to apply the vertical offset/shift properly in WKT
We are trying to use a vertical offset in one of our WKT which is a GDA94/MGA zone 52 CRS by integrating the Australian Height Datum but it does not apply the vertical offset. I am wondering if we are ...
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More information on transformation warning
Software: ArcGIS Pro 2.9.5
Issue: datum transformation error
Want: some details on where the error can be found
Detail: like most folks at some point, I am getting a "transformation warning" ...
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129
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Convert XYZ file with WGS84 Ellipsoid elevations to EGM96 Geoid elevations
I have multiple files in XYZ format in UTM horizontal + WGS84 ellipsoid vertical that I need to convert to UTM horizontal EGM96 geoid elevations. There are about 250'000 points in a an area that is ...
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Are datum and geodetic datum the same?
Although I really read many post and text book, I really don't know 'datum' and 'geodetic datum'. If they are different, could you tell me how?
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Convert GPS heights to AHD
My workplace is looking to replace our Geo 7X and TerraSync. We are looking to replace the Geo 7X with the Trimble DA2 and replace TerraSync with QField.
I'm currently trying to test QField and see if ...
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NAD83 / NAD83 HARN datum transformation
I have data in two projected coordinate systems (PCS), 1) NAD 1983 HARN StatePlane California III FIPS 0403 (US Feet), and 2) NAD 1983 StatePlane California III FIPS 0403 (US Feet). Using HARN, ...
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49
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ArcGIS Pro: Vertical datum Transformation with custom parameters
I have a DEM/tif which has local austrian height values in the raster cells in the MGI datum. (EPSG for the height values: https://epsg.io/5778)
I need to make an inverse 7-parameter vertical datum ...
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125
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Mobile phone GPS altitude decreases when measured from high rise buildings
I am using my mobile phone (Motorola G30) in which I had installed GPS Test app, to measure altitude. I am coming across something really weird. Attached is the screengrab comparing the altitude ...
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Difference between WGS84 datum and WGS84 UTM 15N [closed]
I have two digital elevation models. One’s datum is in WGS84, and the other datum is WGS84 UTM 15N. I am using both for geologic mapping.
What’s the difference between the two datum?
Is it okay for ...
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Using Project tool in ArcMap
I am trying to get my shapefiles to line up using the project tool.
This is the information of the "Input Dataset or Feature Class"
Data Type: Shapefile Feature Class
Shapefile: C:...
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How is datum used in assigning lat and long to point on Earth's surface?
It's accepted wisdom that geographic coordinate systems require a datum in order to assign lat/long to a point on Earth's surface.
However, every point in 3d space already has 3d polar coordinates ...
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463
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Vertical Datum transformation for raster using ArcGIS Pro
I have a DEM raster file on WGS84 CRS and height referenced to ellipsoid on same datum. I want to convert that DEM to local CRS (horizontal & vertical) including the vertical datum transformation. ...
- 1,078
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188
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Gridshift in QGIS 3
I try to access to a specific gridshift for a projection but It doesn’t appear in the datum transformation window.
I’m working on QGIS 3.16.16. I want to use the NAD8398.gsb (from NTv2) in a ...
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If NAD83 is a datum and not a projection, what is happening when set CRS = EPSG:4269 (NAD83)
My understanding is that different projections can use the NAD83 Datum i.e. UTM, Lambert Conformal Conic.
But what happens when I'm working in R and I set the CRS of a shapefile to EPSG:4269 (https://...
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210
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Lowering GeoTIFF raster by fixed value using QGIS
I'm trying to find a way to lower a GeoTIFF raster file by a fixed value. I will try to describe my process so far.
I start by downloading a GeoTIFF from the usgs webviewer, these are in CRS "...
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257
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Defining Geographic Transformation in Project Raster using ArcGIS Pro
I am using ArcGIS Pro 2.9.
I have a raster in D_NAD_1983_2011_Transverse_Mercator and wish to project it to WGS_1984_UTM_Zone_12N so I may export this projected raster as a .tif file.
I have tried ...
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4
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2
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Convert Vertical Datum of GDAL file
I have 2 DTM datasets, the first has a vertical datum of WGS84, while the second has an orthometric vertical datum (maybe EGM96). gdalinfo seems to only provide the horizontal datum info:
Size is ...
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698
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Identifying vertical datum of raster
I have a DEM that purports to use the Canadian Geodetic Vertical Datumn 1928 (CGVD28) where heights are normal-orthometric.
However, when I run gdalinfo dem.tif from the command line the output for ...
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210
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How is Trimble Pathfinder Office transforming positions?
I am struggling to understand how Trimble’s Pathfinder Office transforms and exports GNSS data and I’m hoping someone here can explain. I've seen posts like this and this, and documents like this, but ...
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251
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Raster does not match the target extent and shape of another raster ArcGIS
I have future climate data in .nc format. I transferred them into multiband rasters so I can separate them using another tool and make some calculations. I faced one issue in one variable where it had ...
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246
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Finding the correct aspect ratio from image
I'm trying to put an image over my map.
I know the correct bounding box of it, but when I load it, I see it doesn't fit correctly in the map.
Just for curiosity, I cut a piece of map of same region ...
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218
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Custom datum transformation in bash or Python
I need to transform a shapefile from Deir ez Zor / Levant Stereographic (EPSG:22780) to UTM 36N using 7-parameters Helmet transformation on Ubuntu bash script or Python script.
In ArcGIS, I can ...
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1
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73
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vDatum returns error at Linux command line - fails to accept parameters with GUI
I am trying convert a GeoTiff using VDatum at the Linux command line.
My data reference the Washington State Plane South CRS with z values referencing EGM96. I would like to convert these z values to ...
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111
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Identifying undefined vertical datum
I was given two DEM files covering the same area of Northern California (lets call them File_A and File_B). They're derived from LiDAR that was flown separately in the last 10 years. My goal ...
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383
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PostGIS ST_Transform seems to treat the vertical datum but not the equivalent pyproj Transformer, even so they both rely on Proj
I've narrowed down a problem I met when processing some points having altitude values to the following:
It seems that PostGIS and pyproj do not treat the vertical datum in the same way but both are ...
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125
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Datum transformation with velocity corrections
I have a coordinates with velocity values of some points in ITRF2014 at 2010.0 epoch and I want to convert these coordinates to ITRF96 1998.0 epoch.
I apply the velocity corrections to my coordinates ...
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285
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Special relationship between EPSG:4326 and EPSG:4369
This is a follow-up question to a previous one (Projection between EPSG:4326 and EPSG:4269 using pyproj does nothing).
When using pyproj (python 3.8.8 and pyproj 3.0.1 on windows) to project a point ...
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Projection between EPSG:4326 and EPSG:4269 using pyproj does nothing [duplicate]
According to this quite thorough answer :
Is re-projection needed from SRID 4326 (WGS 84) to SRID 4269 (NAD 83)?
the crs EPSG:4326 and EPSG:4269 are slightly different, due to a difference in one of ...
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99
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Datum transformation not working properly [closed]
I want to create a map with 20 coordinates (UTM), that I have loaded as a CSV-file into QGIS 3.12. The area is located in UTM zone 32 U (northwest of Munich).
As a background I want to use an 80 cm ...
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2
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1k
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Transformation datum from WGS84 to BTM (Bangladesh Transverse Mercator)
I'm changing raster layers in ArcMap from WGS84 to BTM (Bangladesh Transverse Mercator). I first set my data frame to be in BTM
[BTM
Projection: Transverse_Mercator
False_Easting: 500000.0
...
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0
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57
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Visualizing resource dependencies and relationships underlying EPSG CRS
I'll go straight to the point; I remember long ago that I was quite shocked the first time I discovered that EPSG:4326 was kind of an "umbrella" definition on top of many others, which often ...
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NAD27 data distributed in NAD83 by Canadian government
Natural Resources Canada (NRCAN) produced 1:50000 topo maps for all of Canada according to the Natural Topographic System grid configuration. The maps are now considered a legacy product, but GeoTIFFs ...
- 3,668
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243
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EPSG for TanDEM-X Ellipsoid
I have TanDEM-x data and according to the documentation:
"The elevation values represent the ellipsoidal heights relative to the WGS84 ellipsoid in the WGS84-G1150 datum."
I would like to ...
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Understanding EPSG in WKT
I notice several EPSG codes in one WKT. At the first glance it almost is non-intuitive to see so many EPSG codes linked to a single EPSG.
Can someone explain each line of the following WKTs for EPSG:...
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Drawing two points in two datums with same coordinate value
Today I was trying to use ArcMap to find out what is the distance between two locations with same coordinate values in NAD27 and NAD83, but the points I drew appeared to be at the exact same location. ...
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2
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106
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Failure to project shapefile to Mass State Plane NAD83 (meters) SRS with ArcMap
I am working with a shapefile that I have not been able to project to the Mass State Plane NAD83 meters (i.e., EPSG:26986) SRS using ArcMap's "Project" tool. The "Project" tool ...
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205
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Why do I continue to get a datum conflict message even though layers match?
I have a document with multiple raster layers and a set of buffer zones for which I am trying to use the zonal statistics tool to summarize some of the raster information within the buffers. Most of ...
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165
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Using NTV2 transformations in MapInfo
I am investigating the use of MapInfo to apply transformations between GDA94 and GDA2020.
I am using MapInfo Pro 2019.1 so the NTv2.xml file has 10 entries relevant to Australia. They come in pair ...
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249
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Setting a custom projection in ArcGIS, from data provided by the Government of Mauritius?
I am trying to save a custom projection in ArcGIS. It is a local projection used by the Land Unit from the Government of Mauritius. Below are the information provided by the government:
My question ...
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get "Cannot find coordinate operations" in GDAL 3; works in GDAL 2
I get the following error when trying to use GDAL 3.1.2 for computing the LLA from my custom gnomonic projections. Am I setting it up wrong? Missing some information/files? Would it be a misconfigured ...
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367
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How to convert elevation data from Google Elevation API to NAVD 88?
I want to convert the elevation data obtained from Google elevation API to NAVD 88. I understand that Google uses WGS84 with EGM96 Geoid.
Do you know what I should do to convert the elevation data? ...
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128
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Datum transformation in QGIS Server 3.10 [closed]
I have a QGIS project that uses data stored in Web Mercator (epsg:3857) spatial reference system. The project itself has epsg:5514. To have a better precision I use one of datum transformations that ...
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What is MHHW Mean Highest High Water, in terms of datums/coordinate systems?
I'm modeling sea level rise, which entails adding the projected sea level rise for a specific decade to the current MHHW height (I think. I am new to this.)
My question is very general--what is MHHW ...
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609
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Conversion of EGM96 to NAVD88
I am new to ArcGIS and geoids/ellipsoids, and I want to convert a dataset in EGM96 (the USGS SRTM DEMs) to NAVD88. I have the SRTM dataset from NASA downloaded and open in ArcGIS as .hgt files.
I ...
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135
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Geographic Transformations in QGIS 3.12
I have a problem with the way that QGIS handles transformation parameters between coordinate systems based on the Datum NAD27 and those based on the Datum WGS84. In version 3.12.1 I have found that ...
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