topic Re: Help with Coordinate Conversion Using ArcGIS GeometryService in ArcGIS JavaScript Maps SDK Questions

Help with Coordinate Conversion Using ArcGIS GeometryService

swuell — Thu, 10 Oct 2024 04:00:21 GMT

Hello,

I’m currently working on a web application that needs to handle coordinate conversion from WGS84 (used in Google Maps) to NAD83 State Plane Zones, using EPSG codes. The goal is to convert geometries drawn by users (like polylines and polygons) and export them into .shp files for use in external CAD software.

Issues:

The getTransformations() method seems to be missing on the GeometryService object, and I’m unsure how to retrieve and apply the necessary geographic transformations.
There’s a type mismatch error with the geometryService.project() method, where it expects a string, but we’re passing an array of Polygons (some of which may be undefined).

Questions:

What’s the correct way to handle geographic transformations when converting geometries from WGS84 to NAD83 using the ArcGIS API?
Are there specific methods or workflows to use with GeometryService for this type of coordinate conversion?
Any examples or documentation for handling this would be very helpful.

Thanks in advance for your support and guidance!

Sam

Re: Help with Coordinate Conversion Using ArcGIS GeometryService

AndyGup — Thu, 10 Oct 2024 18:21:26 GMT

@swuell it sounds like you might be looking for the API's projection engine: https://developers.arcgis.com/javascript/latest/api-reference/esri-geometry-projection.html#project. This functionality can be run on the client, so no need for a server round-trip.

Re: Help with Coordinate Conversion Using ArcGIS GeometryService

swuell — Fri, 11 Oct 2024 02:40:56 GMT

@AndyGup

I looked into the esri/geometry/projection API, and it seems promising. However, I want to confirm - does this fully replace the need for using GeometryService for coordinate conversion from WGS84 to NAD83 State Plane Zones? My goal is to ensure that the conversion is accurate for polylines and polygons, and then export the data into .shp files.

Would this client-side projection method handle everything without needing a geographic transformation, or do I still need to account for transformation parameters when converting between these coordinate systems?

Thanks for the help!