Latest Contributions by MelitaKennedy

You still need to convert between latitude-longitude and XYZ. See section 4.1.1 of IOGP / EPSG Guidance Note 7-2. It's available from https://www.epsg.org.  ... View more

Hi Xander,  Yes! And they need converted to XYZ. There is an abridged Molodensky method that uses decimal degrees directly--but accuracy is a little less. After converted through the conformal 3D equation, the output XYZ need to be converted back to lat-lnng-ellipsoid h. That conversion is usually iterative but I think there are some direct but less accurate conversions. Melita ... View more

Duh! mkennedy at esri dot com ... View more

Hi Lauren,  I'm very sorry for the late response. Can you post the equation/steps the surveyor gave you for the data? For CAD data it's sometimes possible to assign translation/rotation/scale values to a CAD layer. It's also sometimes possible to modify the projection parameters (scale factor, false easting, false northing) and create a custom coordinate system that gets the data to match up. I have two documents that discuss some of this. If you (or anyone else) sends me an email, I'll send them. They're pretty old now and written for ArcGIS Desktop so workflows may be different if you're using ArcGIS Pro. Melita ... View more

Are you converting the input coordinates to radians and converting to XYZ? The main equations look okay to me. ... View more

We don't support 3D Cartesian in ArcGIS yet. It is in the Esri projection engine, but not exposed in the software using the library. I'm sorry! Melita ... View more

I don't think it's actually MGRS. MGRS is an alphanumeric system for locations. By default, it's only accurate to the nearest meter (+/-0.5, actually a little more) although we support MGRS strings up to mm precision. It might be UTM, which MGRS is based on. ... View more

Hi everybody,  I'm sorry that I didn't respond to this before. Both ArcMap and ArcGIS Pro support on-the-fly reprojection which often includes a geographic/datum transformation component. Both software packages use the same underlaying code, so if you have different results, it's usually because they're not using the same transformation. Open the map or data frame properties and make sure the same geographic transformation is being used.  ArcGIS Pro will often automatically select a transformation, but ArcMap doesn't do that, so it's easy to have the two giving different results. Melita ... View more

Hi Erik, I'm sorry for the delay in responding. There has been no update in the release of files/test data from NGS. However, NGS has said that they are going to delay the adoption of NSRS / 2022 for a few years. See Delayed Release of Modernized NSRS | New Datums | National Geodetic Survey  and Track Our Progress - New Datums - National Geodetic Survey . The summary is that the official adoption will likely occur in 2025, although they'll keep the 2022 name. Meanwhile, we implemented for ArcGIS 10.8.1 and ArcGIS Pro 2 a variant of Lambert conformal conic projection that will be used by NGS for the new state plane and other zones. It was already supported but awkward to use. We're still following NGS closely. Melita ... View more

Thanks, Justin. I just wanted to be sure! I have the files, but am swamped right now. I'll get to them soon. Melita ... View more

Hi Robert!  I don't see the attachment--maybe post a link? Is it the table of different map projections and their properties or the pdf file that lists projected coordinate systems, areas of use, etc? If it's the pdf file, look in the geographic coordinate systems pdf. That contains the vcs info too. Melita ... View more

Hi Justin,  Can you contact me via email so I can get some sample files, if possible. mkennedy at esri dot com The gtf file aren't supposed to be directly editable. The bit of binary at the beginning of the file contains version and string length so it's possible that it's getting messed up and we're failing to read it.  Thanks, Melita ... View more

Hello, What tectonic plate or plates is the data on? Are there other forces that would change coordinates like post-glacial rebound, seismic activity, subsidence, etc.? An area of interest in Australia versus New Mexico versus Washington would likely have different answers. Melita ... View more

I'm sorry for the delay in answering. You can copy the string to a text file (use Notepad). Make sure that it's one line. Save the file with a .prj extension. Now you can import it in ArcGIS Pro through the coordinate systems dialog/picker.  ... View more

Hi Dave,  Is there any chance I can get the DEM for testing? I haven't heard of your issue. If it's possible, and the file's not too large, you can send it to mkennedy at esri dot com. Melita ... View more