Latest Contributions by BojanŠavrič

Hi @akisai, Transformation parameters you are using match NAD_1983_CSRS_To_WGS_1984_2 (WKID::1946) transformation, but they have opposite +/- signs. From your formulas, I see your rotation matrix matches the one for Position Vector and not the Coordinate Frame method. In your case, you are trying to apply the transformation in reverse (from WGS84 to NAD83 CSRS) by using transformation parameters and rotation matrix with opposite signs as they are originally defined. I would need to verify the math first, but I suspect your approach might not match the exact reverse formulas used in ArcGIS. Please see EPSG Guidance Note 7.2 for detailed (exact reverse) formulas and the table of Geographic Transformations in ArcGIS Pro 2.7. I hope this helps... ... View more

Hi Ilia Neudakhin‌! Length calculates a Cartesian length of segments as they appear in a projected coordinate system, in your case the WGS 1984 UTM Zone 15N. Geodesic Length of your segments is always calculated as they appear on the Earth's surface model (in a geographic coordinate system), in your case this is WGS 1984. The WGS 1984 UTM Zone 15N is defined with transverse Mercator projection, which enlarges most areas and distances compare to the true areas and distances on the Earth's surface. This projection, used in the WGS 1984 UTM Zone 15N, is the reason why the Geodesic Length is shorter everywhere.  I hope this helps... ... View more

I am sorry David. I am not sure why this is happening. I am tagging few people and groups on this post and maybe someone will be able to assist you.  Simon Woo‌ Imagery and Remote Sensing‌ raster export‌ raster projection‌ export raster‌  ... View more

David, You could use custom geographic coordinate systems (GCS-es) and set of custom transformations (GT-s) to rotate your raster. See the workflow below.  NOTE: Described workflow is not recommended for high accuracy data and ellipsoids, and it does not work well with vector data.  Suggested workflow To generate a map the globe gores centered on 100° W 40° N, you need to rotate your center point to the North Pole. One way to accomplish that would be using two custom GCS-es and two custom GT-s: 1) Open coordinate system picker, create and store in Favorites two custom GCS-es: e.g. RotatedGlobe1 and RotatedGlobe2. 2) Create a custom geographic transformation from GCS of your data, e.g. WGS 1984, to RotatedGlobe1 GCS. In my example, I used Coordinate Frame method, which includes rotation parameters, passed in seconds: -100° = -360 000". You could also use Longitude Rotation method in this step. This rotates your raster around Earth's rotation axis, or Z-axis and shifts everything to 100° W meridian. 3) Create another custom geographic transformation from RotatedGlobe1 GCS to RotatedGlobe2 GCS. This time you rotate around Y-axis for 50° = 180 000".  This moves your point, 100° W 40° N, to the "North Pole" location. 4) You go back to map properties and select map's coordinate system to be RotatedGlobe2 GCS and select two custom transformations to rotate your data properly.  Here is the resulting rotated raster: 5) You can also create a custom polyconic projected coordinate system and automatically project your data. Note: In ArcGIS Pro 2.5, there are some issues with reading custom coordinate systems from Favorites, so you might have to manually input correct GCS definition when creating it. If done correctly, it will pick your custom transformations.  Here is the result. 6) You might want to overlay with un-transformed graticule to properly clip a gore. Create a copy of 15° graticule vector layer, use Define Projection tool to change GCS of that layer to be RotatedGlobe2 GCS, and add it to your map.  7) To generate other gores, just change Central Meridian parameter to shift everything to the center of the next gore.  Again, you might have to manually input correct GCS definition when creating it due to a bug in ArcGIS Pro 2.5. ... View more

Hi David! Unfortunately, the polyconic projection is not implemented as an oblique map projection in ArcMap and ArcGIS Pro. The Latitude of Origin parameter only moves (0, 0) point to the given latitude on the Central Meridian. ... View more

Hi Marta Bescans, You are missing a transformation, because your definition of GCS_CAPE is a custom definition (WKID is 0). Correct definition is: To make it work with a custom GCS, you need to create a custom geographic transformation that transforms your data between a custom GCS and WGS 1984.  For the whole area of the Chobe District, which covers approximately the area between 23.8 and 26 degrees East and 17.78 and 19 degrees South, you should probably use Cape_UTM_Zone_36S, which has the area of use between 21 and 27 degrees East and 17.78 and 26.88 degrees South. You could also use Cape_UTM_Zone_35S since it covers most of the area of the Chobe District. I hope this helps, Bojan ... View more

Hi Marta Bescansa! I have two questions... 1) Can you provide me the full definition of you Transverse_Mercator coordinate system in GCS_CAPE? Does the coordinate system has an WKID? 2) What version of ArcGIS Pro are you using?  Thanks, Bojan ... View more

Define Projection tool should only be used to assign CS information when data has unknown or incorrect coordinate system. It does not change the coordinates therefore your data moves. To convert (change coordinates) of your data to some other CS, you should use Project tool. ... View more

As Melita Kennedy‌ already mentioned, VCS-es are listed in ArcGIS Desktop and Server / ArcGIS Pro Geographic and Vertical Coordinate System Tables. Map projections are a bit different than coordinate systems. They do not have many properties that can be marked Yes/No/Partially, like map projections do. Their list is also much longer and it keeps growing. However, I am open to ideas. What information would you be interested to see for available VCS-es? Thanks. ... View more

I am not familiar how exactly map service works or if you can use linear units on WGS84, but those values should always be in angular units. Meters do not make any sense when data is in geographic coordinates: a degree span at the equator is different then 1 degree near a pole.  ... View more

raju vayu, coordinates of your point are probably in Projected Coordinate System called WGS 1984 Web Mercator (auxiliary sphere), WKID 3857. They are projected with Mercator Auxiliary Sphere projection from latitude and longitude values defined in Geographic Coordinate System WGS 1984, WKID 4326. If you project those values back to geographic coordinates, you would have much smaller numbers, roughly -79.8523124, 43.2021892. I hope this helps. ... View more

Go to Map Properties, select "Coordinate Systems" and then "New Projected Coordinate System..." Local projection would work for your application. For Longitude and Latitude of Center use geographic coordinates of the origin point, False Easting, False Northing, and Azimuth are 0, and Scale Factor mark as 1. For the Geographic Coordinate System, select the one of your origin point. ... View more

What geographic transformation is used to convert between WGS 1984 and Everest 1830? It might be that your misalignment is caused by incorrect transformation or the lack of it. ... View more

Maps that seem to be aligned with meridians and not with parallels were probably transformed with wrong or without any geographic transformation between WGS84 to D48 datums. Other maps probably do not align because they are in geographic coordinates, latitudes and longitudes, but they have assigned projected coordinate system instead. If you can send me examples of both, I can have a look. I just PM you contact info.  ... View more