Latest Contributions by MelitaKennedy

The additional information is helpful. You're correct that NADCON, specifically its CONUS (contiguous/continuous US) grid file. In ArcGIS, that's the NAD_1927_To_NAD_1983_NADCON transformation. Because NADCON is a piecewise method (in a way), bearings and distances won't be the same. To get those corrected, you would probably have to have a surveyor re-adjust/resurvey the data. Melita ... View more

I don't see the same statement in the current documentation, but I found this in an older version of the documentation: ArcSDE feature classes defined exclusively as single point layers will store point features in the SDO_POINT type. Storing single point features in the SDO_POINT type improves performance when indexing and searching on single point features. All other single and multipart features along with multipart points are stored in the SDO_ORDINATES type. And a knowledge base article about the same thing. Melita ... View more

Hi Christin, #1 and #2 were defined by DMA/NIMA/NGA (US military group). They both have very similar parameter values and will give similar results, but #2 is an update of #1. I can't find as much information on #4 but it listed in EPSG has having a little better accuracy (3m as opposed to 5m) than the NGA-defined transformations. So I have to recommend #4. Melita ... View more

Hi Christin, I think this might be the easiest to modify: .... First, I tried in ArcCatalog to �??Create feature class from XY Table�?� (from the Excel file, using MGRS coordinates as above) and set the input coordinate system to �??Indian 1975�?� and the output coordinate system to �??WGS 1984 UTM Zone 47N�?�, so it should transform it. It created a shape file, but didn�??t display any points. As I thought it might be a problem with the MGRS coordinates, I recalculated them as UTM (by adding a �??7�?� infront of the 5 digit code for the X coordinates, and an �??18�?� infront of the Y coordinates). So I tried it again with �??Create feature class from XY Table�?�, this time with the UTM coordinates, but again the same problem that it can�??t display them. .... Add the digits as before to create UTM coordinates, but when you use the Create Feature Class from XY Table, or use Add XY Data, set the input coordinate system as Indian 1975 UTM Zone 47N. At that point confirm they're in the correct locations, then use the Project Tool to create a new dataset in WGS 1984 lat/lon or WGS 1984 UTM Zone 47N. For the geographic/datum transformation from Indian 1975 to WGS 1984, try Indian_1975_To_WGS_1984_4 if it's available, or Indian_1975_To_WGS_1984_2 if it's not. Melita ... View more

Hi Dan, Does the computer have any type of zip program? They should all support tar files. A tar file is just a collection of files; not really compressed. A tar could then be compressed using a zip or compress program. This one appears to have been compressed with WinZip or something similar after the files were collected together into a tar file. See if MKS is installed by opening a DOS window and typing tar. If you get a command usage line back, type tar -tvf C:\path\to\file\filename.tar or tar -tvf filename.tar if you're in the same directory as the file to see the files inside the tar file. To extract the files: tar -xvf filename.tar C:\path\to\where\you\want\the\raster The tar command is a unix/linux command so if you have a colleague who uses linux, ask them to extract the file. (the data's about 25mb, so a little big to email around) Melita ... View more

Hi Sarina, You just need to copy the gsb file to pedata\ntv2\canada in your ArcGIS installation folder. You will probably need to create the canada folder. http://support.esri.com/en/knowledgebase/techarticles/detail/22608 Melita ... View more

The list of supported coordinate systems is documented here. You may be able to use a well-known text representation of the coordinate system. Geographic (datum) transformations usually do not occur automatically but check the help for some more details. If the information isn't considered proprietary, please feel free to send me the details. We would be happy to add the coordinate system definitions to a future release. Regards, Melita mkennedy at esri dot com ... View more

I can think of two possibilities: 1. If you're looking at the raster in ArcMap, make sure that the data frame's display units (data frame properties, general tab) are set to meters). 2. Did you use the Define Projection Tool or the Project Raster Tool? The first one updates the metadata but doesn't change the raster's extents or georeferencing. If you did use the Define Projection tool, use it again to set the coordinate system back to WGS84, then use the Project Tool. I hope this helps, Melita ... View more

The first equation, h = H + N is correct which means the second is not. It should be: H = h - N My references include Wolfgang Torge's Geodesy, 2nd Edition and National Geodetic Survey. I've sent an email to a colleague on the raster team. Melita ... View more

Hi, Check out this help topic: Constructing a high- or low-precision spatial reference Melita ... View more

Hi Beth, Oh, I see it now. I think the DMS setting is for display only; at least, I haven't been able to get it to take any DMS values either interactively or through a link table. You might need to enter DD values (maybe via link tables where it'll be easier to edit?) and run the values out to 15-16 digits. That's double precision and the most that can get stored anyway. So: 34.66666666666667 12 34567890123456 Melita ... View more

Hi Beth, I'm not 100% sure, but I think the link table wants decimal degrees, or xy values, as double precision values, not degrees-minutes-seconds. You may need to convert your corner values into decimal degrees. Melita ... View more

This may be what you're confused about... When part of a UTM-related coordinate system name, 'S' means South and 'N' means North for the Southern and Northern hemisphere zones. If given a UTM string or notation like 17S 432938 3868920, the 'S' could mean a latitude band. That is, the data falls between 32N and 40N. Melita ... View more