› ›

Raster (Tiff) and Shape Polygons not aligned

cassherncasshern Global Mapper UserPosts: 7
edited July 2012 in Georeferencing Imagery Discussion
Hi,

I am new to global mapper. Currently i have one raster image of buildings and another shapefile polygons of those buildings. Apparently when i load them together onto gobal mapper v11.01, those polygons are way off from the raster's buildings. I wondered what actually caused this problem and what are the steps i can follow to solve it?

Additional information:
1) i checked their meta-data in control center and discover that their NSEW Latitude and Longitude are slightly different.

2) I put them on ArcMap and ArcMap prompted that the Raster is of WGS84 while the shapefile is of Geographic coordinate system and i am being asked to transform.

3) I tried to do a geo-referencing on ArcMap but there are far too many controls points to set due to the amount of buildings and the result is also not too satisfactory.

Please kindly assist.

Thank you.

Comments

  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited February 2012
    It sounds like maybe the datums are different between the 2 files so one of them is being loaded with the wrong datum and therefore being slightly mis-placed. Is it possible for you to post the 2 files here or email them to gmsupport@bluemarblegeo.com so that I could take a look?

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • cassherncasshern Global Mapper User Posts: 7
    edited February 2012
    Hi Mike,

    Sorry i couldnt email u those files as they are simply too large (in gb). I have checked their datum in ArcMap and the tiff is D_WGS_1984 while the shape file is D_WGS84. However in Global Mapper, both files' Proj_Datum are WGS84 and they have the same EPSG code too. Apparently only their West Long, North Lat, East Long and South Lat are different. Is there any way i can do to adjust them to be the same West Long, North Lat, East Long and South Lat (if that is going to solve my prob)? Or how can i generate a new shape file based on this tiff (original lat long)?

    Thank you.
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited February 2012
    Can you first try downloading the latest v13 install from the links below and see if the data lines up properly there to see if you are just seeing an issue in v11.01 that has since been fixed? The data should load fine in the trial:

    32-bit: http://www.globalmapper.com/global_mapper13_setup.exe
    64-bit: http://www.globalmapper.com/global_mapper13_setup_64bit.exe

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • cassherncasshern Global Mapper User Posts: 7
    edited February 2012
    i wonder if this 11.01 issue that u mentioned is solved in Global Mapper 12? because it doesnt seems to be solved with my global mapper 12.
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited February 2012
    I would have to know which issue it is first. If you download the v13 trial that will be newer than v12 anyway.

    If you want to send me the files you can FTP them to ftp.globalmapper.com using a username of 'upload@globalmapper.com' and a password of 'upload'.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • cassherncasshern Global Mapper User Posts: 7
    edited February 2012
    the issue is not with the global mapper but is with the Lat and Long of the 2 files.

    As you can see from the below info of these 2 files, their WEST LONGITUDE, NORTH LATITUDE, EAST LONGITUDE and SOUTH LATITUDE are different. How can i make both of their WEST LONGITUDE, NORTH LATITUDE, EAST LONGITUDE and SOUTH LATITUDE the same?

    Shape file
    AREA COUNT=22149
    AREA VERTEX COUNT=178977
    LINE COUNT=0
    POINT COUNT=0
    UPPER LEFT X=103.8580522199
    UPPER LEFT Y=1.3657513607
    LOWER RIGHT X=103.9104190726
    LOWER RIGHT Y=1.3132897697
    WEST LONGITUDE=103° 51' 28.9880" E
    NORTH LATITUDE=1° 21' 56.7049" N
    EAST LONGITUDE=103° 54' 37.5087" E
    SOUTH LATITUDE=1° 18' 47.8432" N
    PROJ_DESC=Geographic (Latitude/Longitude) / WGS84 / arc degrees
    PROJ_DATUM=WGS84
    PROJ_UNITS=arc degrees
    EPSG_CODE=4326
    COVERED AREA=13.141 sq mi

    Tif File
    UPPER LEFT X=103.8558300169
    UPPER LEFT Y=1.4015825884
    LOWER RIGHT X=103.9636551200
    LOWER RIGHT Y=1.2930588436
    WEST LONGITUDE=103° 51' 20.9881" E
    NORTH LATITUDE=1° 24' 5.6973" N
    EAST LONGITUDE=103° 57' 49.1584" E
    SOUTH LATITUDE=1° 17' 35.0118" N
    PROJ_DESC=Geographic (Latitude/Longitude) / WGS84 / arc degrees
    PROJ_DATUM=WGS84
    PROJ_UNITS=arc degrees
    EPSG_CODE=4326
    COVERED AREA=55.972 sq mi
    NUM COLUMNS=20480
    NUM ROWS=20480
    NUM_BANDS=3
    PIXEL WIDTH=0.0000053 arc degrees
  • cassherncasshern Global Mapper User Posts: 7
    edited February 2012
    Forget to add that the shape file polygons are still not aligned to the raster image's buildings on Global Mapper v13. Thanks.
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited February 2012
    I don't think just getting the lat/lon bounds to line up perfectly is the answer. The SHP file lat/lon bounds represent the bounding box of all of the features in the SHP file, while for the TIFF file it is the bounds calculated from the geo-positioning (either embedded in the TIFF or from a world file) and those extend to the outer edge of the pixels of the TIFF. Unless the features in your SHP file go exactly to the same pixel bounds as the TIFF I would not expect them to result in the exact same lat/lon.

    How far off are the Shapefile features from the TIFF? Is the shift in a particular direction? Are you being prompted to select a projection for either one? I'm wondering if maybe the datum for one of the files isn't really WGS84 but is something else, like maybe a Google Maps datum (this one would cause a due-north shift).

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • cassherncasshern Global Mapper User Posts: 7
    edited February 2012
    The shift seems to be a downwards and right direction (South-East direction?) So what should i do on global mapper to solve this issue?
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited February 2012
    You can right-click on a layer in the Control Center and select the shift it or reposition it via rectification (this works for vector layers as well), but it still sounds like the real problem is that the datum is not really WGS84 for one of the files. An incorrect datum selection can cause shifts in any direction up to hundreds of meters. What is the source of the data? Does it come with any metadata that might describe the actual projection/datum of the coordinates in the file?

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • cassherncasshern Global Mapper User Posts: 7
    edited February 2012
    The METADATA is mentioned in the previous posts:

    Shape file
    AREA COUNT=22149
    AREA VERTEX COUNT=178977
    LINE COUNT=0
    POINT COUNT=0
    UPPER LEFT X=103.8580522199
    UPPER LEFT Y=1.3657513607
    LOWER RIGHT X=103.9104190726
    LOWER RIGHT Y=1.3132897697
    WEST LONGITUDE=103° 51' 28.9880" E
    NORTH LATITUDE=1° 21' 56.7049" N
    EAST LONGITUDE=103° 54' 37.5087" E
    SOUTH LATITUDE=1° 18' 47.8432" N
    PROJ_DESC=Geographic (Latitude/Longitude) / WGS84 / arc degrees
    PROJ_DATUM=WGS84
    PROJ_UNITS=arc degrees
    EPSG_CODE=4326
    COVERED AREA=13.141 sq mi

    Tif File
    UPPER LEFT X=103.8558300169
    UPPER LEFT Y=1.4015825884
    LOWER RIGHT X=103.9636551200
    LOWER RIGHT Y=1.2930588436
    WEST LONGITUDE=103° 51' 20.9881" E
    NORTH LATITUDE=1° 24' 5.6973" N
    EAST LONGITUDE=103° 57' 49.1584" E
    SOUTH LATITUDE=1° 17' 35.0118" N
    PROJ_DESC=Geographic (Latitude/Longitude) / WGS84 / arc degrees
    PROJ_DATUM=WGS84
    PROJ_UNITS=arc degrees
    EPSG_CODE=4326
    COVERED AREA=55.972 sq mi
    NUM COLUMNS=20480
    NUM ROWS=20480
    NUM_BANDS=3
    PIXEL WIDTH=0.0000053 arc degrees

    If you suggest that datum is not really WGS84 for both files, then what ways can i do to make both files' datum to be the same?
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited February 2012
    There is no doubt that WGS84 is what the files are being interpreted as, what I'm saying is that might not be correct. Are you being prompted for the projection for either file when loading it? You can change the projection/datum assignment for a file after load by going to the Projection tab of the Options dialog for the layer. That way you can correct the projection/datum assignment of an already loaded layer that came in with the wrong projection/datum.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • klsears74klsears74 Global Mapper User Posts: 4
    edited June 2012
    Hi. I am working in Global Mapper v13.2 64-bit. I am having a problem with control points. I save the file when I have to quit the georeferencing process for the day. When I reload the points into the project the next morning, they have shifted. Help please.
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited June 2012
    How are you saving and reloading the control points and in what way have they shifted? When you say you are restarting the georeferencing process, how exactly are you doing that?

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • klsears74klsears74 Global Mapper User Posts: 4
    edited June 2012
    I go to File --> Save control points to a file, then I save the file as a .gcp. Then, when I restart the program the next morning and open and set the datum and projection, I go to File --> Load control points from a file, and choose the .gcp I saved. I have always done it this way, but haven't had a problem until now.

    When I restart the process since the points don't match, I just delete the .gcp and start all over.

    Thank you for any help you can give.
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited June 2012
    That is strange, how far are the GCPs shifting? Can you provide a sample GCP file and the file you are rectifying? When you are rectifying are you using File->Rectify Imagery or first loading the file then right-clicking on it in the Control Center to Reposition it?

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • klsears74klsears74 Global Mapper User Posts: 4
    edited July 2012
    Good morning. I tried the process again this morning and it is fine. Would this problem occur if too many points were put in for georeferencing?

    Thanks.
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited July 2012
    The number of points shouldn't really make any difference. If you had selected an incorrect projection or datum that might make a difference. If this crops up again in a reproducible manner let me know.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • klsears74klsears74 Global Mapper User Posts: 4
    edited July 2012
    I was able to reproduce the problem again. I created a word document explaining what happens. If I send an email to the above address, will it go straight to you?

    Thanks.
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited July 2012
    Yes, you can send it to gmsupport@bluemarblegeo.com and I'll get it unless one of the other support folks gets to it first. Probably me though since it's almost 5PM EST where the Blue Marble offices are.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
Sign In or Register to comment.