topic Re: Creating Microwave Paths with Z Values in ArcGIS Data Interoperability Ques.

Creating Microwave Paths with Z Values

AdamRepsher — Thu, 28 Jan 2021 16:03:48 GMT

Hi Everyone,

I have a CSV file of microwave paths. Each record has two sets of X, Y and Z to make a line. Z comes in either feet or meters. X and Y are WGS84 - which i defined in the CSV Reader.

So far, I think I have figured out how to make just the 2D lines. Use two VertexCreator transformers together, first one configured with the "From" X, Y - and the second with the "To" X, Y. I use the Add Point Mode to step from the first VertexCreator making the original point and then ADDING the next POINT to make a line with the second VertexCreator.

In both of those VertexCreators, would I have to do a conversion of either Meters or Feet to Degrees for the Z value since I have defined WGS84 in the reader?

Thanks,
--Adam

Re: Creating Microwave Paths with Z Values

BruceHarold — Thu, 28 Jan 2021 16:13:35 GMT

Adam, WGS84 elevations are defined in meters above/below the ellipsoid so convert feet to meters except if your Z values are from the center of the earth then you'll need to additionally do a vertical datum transformation with CsMapReprojector.

A wider issue is using WGS84 at all, if you're doing anything involving visibility or density or area a local projected coordinate system would be better.

Re: Creating Microwave Paths with Z Values

AdamRepsher — Thu, 28 Jan 2021 16:25:19 GMT

@BruceHarold - I have Meters Above Ground Level.

I may have to add something that gives me the elevation at the points? OR am I getting too deep into my thinking? Would the recorded height be correct above any elevation surface that I would be using?

Re: Creating Microwave Paths with Z Values

DanPatterson — Thu, 28 Jan 2021 16:17:58 GMT

Height in degrees makes no sense since the physical distance between lines of latitude and longitude is not constant and you don't want to introduce that in your Z values.

It is standard practice to have your elevation values in planar units and your locational coordinates in either spherical or planar units.

Should you wish to use ArcGIS Pro, you can produce lines using

XY To Line (Data Management)—ArcGIS Pro | Documentation

if you organize your csv table appropriately.

Re: Creating Microwave Paths with Z Values

BruceHarold — Thu, 28 Jan 2021 16:20:44 GMT

If you have AGL heights then you'll need a ground surface for any analysis.

Re: Creating Microwave Paths with Z Values

AdamRepsher — Thu, 28 Jan 2021 16:24:54 GMT

@DanPatterson - Thank you for the education. - I got that part, as @BruceHarold mentioned above.

I am trying to complete this task in a SpatialETL tool within Pro's Data Interoperability Extension - not as a one-off tool run.

Re: Creating Microwave Paths with Z Values

AdamRepsher — Thu, 28 Jan 2021 16:44:16 GMT

@BruceHarold wrote:
If you have AGL heights then you'll need a ground surface for any analysis.

Sorry for having to ask this @BruceHarold...

Would "analysis" include creating these lines - like I am doing right now?
If so - what Transformer would I be using and where would I be inserting it? Before the VertexCreators and somehow use a value from it in an Arithmetic Editor for Z...

Am I writing the Z directly from the AGL that I have - and it will appear correctly above a ground surface in any analysis I want to do with it in the future?

Sorry - I am very new to 3D as well as Data Interop....

EDIT - and as a note, I am simply trying to get these lines out of a CSV right now. I have to begin with the Coordinate System given to me to get anywhere....

--Adam

Re: Creating Microwave Paths with Z Values

BruceHarold — Thu, 28 Jan 2021 16:42:38 GMT

I was thinking things like visibility analysis; constructing your 3D geometry is OK with VertexCreator, you just need 'ground' to visualize it. Z from the AGL values is OK. There are specialist solutions for radio propagation which I don't know anything about but Esri has a specialist if you need.

Re: Creating Microwave Paths with Z Values

AdamRepsher — Thu, 28 Jan 2021 16:59:15 GMT

That's okay Bruce. Thank you for the extra input.. We already do line-of-sight analysis with a local projected coordinate system for our assessment of future microwave shots - one at a time as they are requested. Right now, I have a little over 350 lines I have to produce from this CSV dataset with coordinates given to us in WGS84 - and I may have to update the data monthly - so I wanted to start this process off in a Data Interop SpatialETL tool right off the bat.

In the first steps, I have to create the lines in WGS84 since that is what I am given - unless I am mistaken. I'll get into reprojecting it later.

Thanks again!

--Adam

Re: Creating Microwave Paths with Z Values

BruceHarold — Thu, 28 Jan 2021 17:05:51 GMT

You should be OK then, but in case you get into any arguments with geodesists make sure you record that the heights are AGL. If the CSV data is available electronically somehow, say FTP, HTTP, email, cloud storage etc. then you can automate download and processing end to end with Data Interop.