Elevation API vs Elevation Layer Results

jacobgqc

Hello,

We created a small "elevation checker" utility in React that uses an ElevationLayer object (from @ArcGIS/core/layers/ElevationLayer) queryElevation function to get the elevation data for a clicked point on a map. This works great, and the elevation values we get back seem to be the most accurate from among other sources we've seen.

Related, we wanted a way to programmatically verify the accuracy of a set points' elevations and decided to use https://elevation-api.arcgis.com/arcgis/rest/services/elevation-service/v1/elevation/at-point , which seemed to be a perfect fit. However, the results appear to be rounding to the nearest integer value, whereas the elevation layer query returned values with two decimal places.

I've compared several geographic locations in North America (Vancouver, San Francisco, Cincinnati, NYC) and all of them returned integer values from the API and two decimals of precision in the elevation layer.

Is this expected? Is there any way to programmatically get the same values returned by ElevationLayer.queryElevation()?

Thanks,
Jake

VikramPonnuswamy

Hey @jacobgqc thank you for the post. Yes this is expected. I am interested in your use case to better help you. What is that you are trying to built?

Vikram

VikramPonnuswamy

Hey, @jacobgqc we've now updated elevation service to return z value to 10cm precision, i.e. to 1 decimal place. So example response:

{
  "result": {
    "point": {
      "x": -117.194769,
      "y": 34.057289,
      "z": 395.8,
      "spatialReference": {
        "wkid": 4326,
        "vcsWkid": 105700
      }
    }
  },
  "elevationInfo": {
    "relativeTo": "meanSeaLevel"
  }
}