 |
 |
I agree with Keith On Wed, Oct 10, 2018, 10:46 AM Miller, Keith <[log in to unmask]> wrote: > I may be showing my ignorance here, but I would think that the fact that > the five different lat longs all plotting at the same point showed that > there WERE transformations taking place. If the “points” were supposed to > represent the same physical location on the earth, then they SHOULD all > overlap, as long as you tell ArcGIS the proper coordinate system used, > which is what it sounds like you did in the second step. The first step > showed the problem with not having proper documentation, in that the same > “point” showed up in five different places on the map. What am I missing? > > > > Sincerely, > > Keith Miller > > > > *From:* Northeast Arc Users Group [mailto:[log in to unmask]] *On > Behalf Of *Christina Herrick > *Sent:* Wednesday, October 10, 2018 10:49 AM > *To:* [log in to unmask] > *Subject:* Re: Transforming xy data > > > > I'd be curious to know if anyone figures this out. I gave it a try and > I'm also having the same issues. > > > > *Christina Herrick* > > Research Scientist > > V: 603.862.2639 | F: 603.862.0188 > > *University of New Hampshire* > > *Institute for the Study of Earth, Oceans, and Space* > > *Earth Systems Research Center* > > Morse Hall, 8 College Road > > Durham, NH 03824 > > > > ResearcherID: O-3375-2017 > > ORCID ID: 0000-0002-8384-9450 > > > > > > > > On Wed, Oct 10, 2018 at 10:19 AM Dan Martin - NOAA Federal < > [log in to unmask]> wrote: > > Good morning, > > > > I will try to make this as understandable as possible: > > > > Objective: To show why proper metadata (datum/realization wise) is > important. > > > > I got the datasheet for a geodetic control point in NJ. It has a current > NAD 83(2011) lat/lon. It also has many superseded coordinates (Lat/Lon) > going all the way back to NAD 83(1986). > > > > I created a map in ArcMap, and established the data frame coordinate > reference to be NAD 83(2011) > > > > I then created a .txt file of the various NAD 83 positions that reflected > the various realizations 2011, 2007, 1996, 1992, 1986. > > > > I added the xy data to the map and told ArcMap that they were Geographic > NAD 83 (2011) (which of course they were not). As one would expect, I got > 5 dots on the map with a spatial separation that reflected the differences > between the 5 realizations. > > > > Next I created one file for each coordinate, and added each file one at a > time. This time, I told ArcMap that the coordinate system for each file > was actual realization of the position, i.e., when adding the NAD 83(2007) > lat and lon, I told ArcMap that the coordinate system of the position was > in fact NAD 83(2007). The result was 5 dots that plotted exactly on top of > the other 5 dots, i.e., no transformation took place? > > > > Am I doing something wrong? > > > > Thanks for any input. I have attached the files if anyone wants to test > this them selves. I have provided the files to some of my counterparts and > they experienced the same. > > > > Dan > > > > > Daniel J. Martin > Northeast Regional Geodetic Advisor > > (ME, NH, VT, MA, CT, RI, NY, NJ) > NOAA/NOS/National Geodetic Survey > > Email: [log in to unmask] > > Cell: 240-676-4762 > > > > ------------------------------------------------------------------------- > This list (NEARC-L) is an unmoderated discussion list for all NEARC Users. > > If you no longer wish to receive e-mail from this list, you can remove > yourself by going to http://s.uconn.edu/nearcsubscribe > <https://urldefense.proofpoint.com/v2/url?u=http-3A__s.uconn.edu_nearcsubscribe&d=DwMFaQ&c=c6MrceVCY5m5A_KAUkrdoA&r=Fgp5Fj8BRI312O5a7XGOsE368byJfExS1LmNrumOv3s&m=SyeEl6O2EkDJ78lMtP_8EFzRH5GH_XbgF3TwR6spuyk&s=oal8vGy1_uILrcFkAnUZkoOWrBuCxHKSN5vV7OK_A30&e=>. > > > ------------------------------------------------------------------------- > This list (NEARC-L) is an unmoderated discussion list for all NEARC Users. > > If you no longer wish to receive e-mail from this list, you can remove > yourself by going to http://s.uconn.edu/nearcsubscribe. > ------------------------------------------------------------------------- > This list (NEARC-L) is an unmoderated discussion list for all NEARC Users. > > If you no longer wish to receive e-mail from this list, you can remove > yourself by going to http://s.uconn.edu/nearcsubscribe. > ------------------------------------------------------------------------- This list (NEARC-L) is an unmoderated discussion list for all NEARC Users. If you no longer wish to receive e-mail from this list, you can remove yourself by going to http://s.uconn.edu/nearcsubscribe.