Skip to main content
Question

Querying NED Data from the Web

  • February 13, 2018
  • 1 reply
  • 8 views

So I am trying to create a workbench that will take a 3D Polyline and drape the vertices based on the USGS 10m NED data. I would like for the data to be queried based on the 3D Polyline which will be projected into a UTM Zone based on US Survey Feet. The thought of using an HTTPCaller has been suggested, however I am not quite sure on the steps to take to ensure the query is accurate.

Has anyone achieved this?

This post is closed to further activity.
It may be an old question, an answered question, an implemented idea, or a notification-only post.
Please check post dates before relying on any information in a question or answer.
For follow-up or related questions, please post a new question or idea.
If there is a genuine update to be made, please contact us and request that the post is reopened.

1 reply

fmelizard
Safer
Forum|alt.badge.img+20
  • Safer
  • 3719 replies
  • February 20, 2018

Hi @jberneathy,

 

You will have to build you're request to meet the requirements of the servers you are accessing. Is there any documentation at USGS that you can use - or, if applicable, the general structure of the URLs you want to access? - this looks like a good place to start: https://nationalmap.gov/epqs/

For me the first place I would start would be learning how the requests work, sending manual HTTP requests and getting the response I'm expecting. Once I have that then I would look to automate the extraction of the required info from your Polylines and build it into the request. We have a number of tools on how you might go about doing this but it all depends on the structure of the request. The next part will involve getting the Data from the response into FME.

 

 

Have you looked at the MapzenAWSDEMDownloader - This is a custom transformer. It might save you some work. I'm not sure if it's the same data but it's a DEM and the resolution looks to go as high at 10 m per pixel. Something to think about anyway.