Global Mapper v26.0

GlobalMapper changing my data

limeyx
limeyx Global Mapper User
edited May 2010 in Bug Report
I have a shapefile that has some important GPS waypoints in it.

I have multiple projects, each of which opens this master shapefile as well as their map data.

I have one particular location that if I enter it in the layer of my master shapefile, then once I type the data, GM actually records it in a different location than the data I typed.

if I enter it in "User Defined Features" layer then it's fine UNTIL i move it to the layer for my master file when it gets corrupted.

Am I doing something wrong ? For now, it appears to be just this one data point...

GM 11.02

EDIT: Scratch that, it still changes the data but not in any way that I can understand. This seems very broken but so far with just this geographical area.

Comments

  • global_mapper
    global_mapper Administrator
    edited May 2010
    Can you be more specific about what it is doing? I'm not real clear on how the data is being corrupted.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • limeyx
    limeyx Global Mapper User
    edited May 2010
    limeyx wrote: »
    I have a shapefile that has some important GPS waypoints in it.

    I have multiple projects, each of which opens this master shapefile as well as their map data.

    I have one particular location that if I enter it in the layer of my master shapefile, then once I type the data, GM actually records it in a different location than the data I typed.

    if I enter it in "User Defined Features" layer then it's fine UNTIL i move it to the layer for my master file when it gets corrupted.

    Am I doing something wrong ? For now, it appears to be just this one data point...

    GM 11.02

    EDIT: Scratch that, it still changes the data but not in any way that I can understand. This seems very broken but so far with just this geographical area.


    Sure.

    I go to the Digitizer tool.
    Right click the map and say "Create new Point/Text feature at specified location"

    Type in my location in minutes/degrees

    Then I give the waypoint a name

    the location is around 32.47/118.23 area

    I click OK.
    at some point later, the 118.23 gets changed to 118.24 something
    I have all data in zone 11

    if I do not open any files, and just create this point, it is fine.
    If i load my data of this area (just the map) then it is sometimes fine
    If I load the map + my shapefile of waypoints, then suddenly its changed.
    Or if I move it from User Features layer to the layer of my waypoints.

    It so far ONLY seems to happen with 118.23 area as far as I can see
  • limeyx
    limeyx Global Mapper User
    edited May 2010
    It was sugested by a friend that I may have a datum mismatch, and that may shed some light here.

    My MAP is WGS84 and zone 11

    my shapefile was NAD83

    However, if I change my shapefile to NAD83/Zone 11, it still adjusts the data but ... in the other direction.

    Obviously it seems I have some kind of mismatch here but I have no idea what
  • global_mapper
    global_mapper Administrator
    edited May 2010
    When you are creating a new point at a specified location then the current projection/datum selected on the Projection tab of the Configuration dialog is used for the coordinates. Depending on what you have selected there for the datum, the same numeric latitude/longitude values may be at slightly different locations on the earth, so it is important to verify you have the proper datum for your location selected on the Projection tab of the Configuration dialog prior to creating the point at those coordinates.

    As a note, the WGS84 and NAD83 datums are coincident to within a meter, so just the difference between those datums is insignificant.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com