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ImageStation Surface Formats

by Technical Evangelist ‎09-19-2019 07:33 AM - edited ‎09-20-2019 06:35 AM (446 Views)


What elevation formats are supported by the ImageStation products?


Supported Elevation Data Formats
Elevation data files provide the land surface information that is used in orthorectification to correct relief displacement. This data can consist of regularly spaced ground elevation grids, of triangulated networks of ground elevations, or of regularly or irregularly spaced ground elevations in ASCII format. ImageStation OrthoPro supports the following elevation data file formats:



  • GeoTIFF (.TIF)
  • Intergraph grid (.GRD)
    • Intergraph triangulated (.XYZ)
    • Intergraph triangulated (.TTN)
    • Intergraph triangulated (.DTM)
    • Intergraph ASCII queue (.QUE)
    • Esri band-interleaved-by-line (.BIL, .FLT)
    • Esri binary grid (.ADF)
    • Esri ASCII grid (.ASC)
    • LIDAR (.LAS/.LAZ)
    • ASCII (.ASC)
  • SRTM (.HGT)
    • USGS SDTS (.DDF)
    • USGS DEM (.DEM)
    • NIMA DTED (.DT0, .DT1, .DT2)
    The USGS files and NIMA files contain coordinate system information and require no associated coordinate system files. For Intergraph files, you must either define the coordinate system manually or select an associated design file that contains the coordinate system information.


    Supported Surface Formats
    ISDQ loads and saves surfaces in several formats. The preferred format is the Intergraph DTM format.
    The DTM format:
    • Supports morphological features, such as break lines, boundaries, and contours.
    • Supports (limited) multiple outer boundaries (islands).
    • Is a TIN format (irregular/non-gridded) and is therefore more accurate than grid surface formats.
    • Is the most efficient for ortho production.
    TIN refers to Triangulated Irregular Network. Although the table below refers to many formats as "TIN" only the DTM format stores the triangles of the surface within the file. This makes it more efficient for use in other applications when compared to other TIN formats, such as ASCII files, because the file does not need to be triangulated in memory before being probed for elevations.
    This table outlines the capabilities of supported surface file formats:
    Supported Format Type  Read  Write  Internal Georeferencing
    ADF Grid/Raster Yes No Yes
    ArcGRD Grid/Raster Yes No No
    ASCII TIN Yes Yes No
    BIL/FLT Grid/Raster Yes No No
    DEM/DDF Grid/Raster Yes Yes Yes
    DGN TIN Yes No Yes
    DTED Grid/Raster Yes Yes Yes
    DTM TIN Yes Yes No
    GeoTIFF (three channels, 24-bit integer, shaded relief) Grid/Raster No Yes Yes
    GeoTIFF (one channel 16-bit integer) Grid/Raster Yes No Yes
    GeoTIFF (one channel 32-bit float values) Grid/Raster Yes Yes Yes
    Hgt (SRTM) Grid/Raster Yes No Yes
    HPC (Hexagon Point Cloud) TIN No Yes No
    IMG Grid/Raster Yes No Yes
    Intergraph GRD Grid/Raster Yes Yes No
    ISPM (Photo files) TIN Yes No Yes
    LandXML TIN Yes Yes Yes
    LAS/LAZ TIN Yes No Yes
    QUE TIN Yes Yes No
    SCOP TIN Yes No No
    TTN TIN Yes No No
    Intergraph XYZ TIN Yes No No
on ‎10-02-2020 09:47 AM

What is the best tool and process to convert Bentley Inroads dtm to Intergraph dtm for use in ISOP? thanks!

by Technical Evangelist
on ‎10-02-2020 10:38 AM


Dgn2Dtm loads a DGN file and converts it to a TIN DTM format file.

If the DGN has an embedded coordinate system you can open the file with DefCsf.exe to review the coordinate system.

The mapping of the DGN layers to DTM features is defined using the filter parameter. The mapping may be defined using an .ini file from ISAE or ISDC.

Command Parameters


Default Value




Input DGN filename.



(Optional) Input coordinate system filename.


Input filename with .dtm extension

Name of the output file. If no output filename is given, the extension of the input file is replaced with .dtm. If the output file exists (e.g. is the input file), it is overwritten silently.



(Optional) Output coordinate system filename.



Define the mapping of DGN levels, colors, etc., to DTM features. You can define more than one mapping. The command also accepts an ISAE or ISDC .ini file.



Creates a property with name <YYYY-MM-DD HH:MMSmiley FrustratedS> and content <text>.



Flag to output additional information. Options: yes or no.


--filter  "INT level 30 color red weight 1 style 2"
--filter  "BRK level 20 color green weight 1 style 2"
--filter  "EXT level 40 color blue weight 2 style 3"
--filter  "REG level 50 color -1 weight -1 style -1"

Import features based on level and symbology. "-1" indicates any occurrence of the indicated symbology or level type.


--filter "EXT levelname {Level 1}"
--filter "REG levelname {Level 6}"
--filter "REG levelname {Level 7}"
--filter "REG levelname {Level 10}"
--filter "INT levelname {Level 3}"
--filter "BRK levelname {Level 4}"

Import features using the level names.


--filter "C:\Program Files (x86)\Hexagon\ImageStation DTM Collection\cfg\Default_dtm_sym.ini"
Import features using an INI file.