The XV_VTDF is a viewer for TDF format files (extension to TIFF 6.0 format for storage of high-resolution satellite data). More information about TDF format and relevant topics, as well as satellite data in this format you may receive from Space Monitoring Information Support lab (Space Research Institute, Moscow, Russia)

The XV_VTDF is a Windows 3.1 program (must also run in Win95 as a 16-bit application). This package is currently freeware, and is subject to the standard disclaimer (i.e. the developers take no responsibility for any losses due to use of this software etc.).

Unfortunately, the on-line help (file: xv_vtfd.hlp) is sufficiently outdated, and so far not included into this package. The preparation of complete on-line help is currently in progress. Hopefully it will be available in a couple of weeks . Until then, please explore the TDF viewer on your own and guess what is the commands are intended to :-). Sorry for inconvenience.

Here is a short list of keyboard and mouse operations and other not obvious topics.


Download the XV_VTDF.ZIP file into temporary directory and unzip it. Find there setup.exe and run it from WINDOWS.


PgUp PgDn switching between image pages (AVHRR channels)
Arrows moving the cursor around in image window
Shift + Arrows moving the zoom window around the image
Ctrl + Arrows scrolling status-bar left/right


Left button double-click - drag rectangular region of interest. Double-click again to restore ROI to full image size

Right button double-click - enter selection of arbitrary-shaped area of interest. Select by left-clicking the consequent points or by dragging with left button. LEFT double-click to close the area and select it. RIGHT click to cancel operation and discard area.

Left button click/drag - point / section popup menu

Right button drag - (if Zoom ON) move the Zoom window around the image

Command line

Until command-line options are documented, these are examples

of main command-line switches:

XV_VTDF -? - startup dialog for setting parameters

XV_VTDF <filename> - load TDF file at startup (default size)

XV_VTDF <filename> -x -y - load TDF file, set image size to that in the file specified

XV_VTDF -x 512 -y 480 - set image size to 512x480

Image size

The XV_VTDF operates with fixed-size satellite images in TDF format. To change default image size, you may:

  1. either start program with -? option,
  2. or specify dimensions explicitly on the command line or using the TDF-file size,
  3. or edit the XV_VTDF.INI settings (ImageSizeX, ImageSizeY) for permanent change of default settings.

Initial (default) settings are 512x512 pixel.

WinG support

WinG is the free Microsoft's software package for fast 8-bit graphics in Windows 3.1 environment. The package is recognized automatically and is supported by the XV_VTDF software. All you need is to install the WinG libraries on your Windows 3.1 system, and the image rendering by XV_VTDF will be significantly accelerated. The WinG libraries can be obtained from Microsoft ( or via FTP: