FAQ
BT to CAL Conversion
What are BT files?
BT is a binary terrain format developed by Ben Discoe for the Virtual Terrain Project (VTP) to store regular elevation grids used in 3D terrain visualization and simulation. A file of this type consists of a fixed 256-byte header followed by an uncompressed array of elevation samples, stored as 16-bit integers, 32-bit integers, or 32-bit floating-point numbers. The header carries the grid dimensions, sample size, horizontal units, geographic extents, datum, and, for projected data, a UTM zone, while a complete projection definition may be supplied in an accompanying .prj file. Elevation samples are written column by column, starting from the western edge and moving south to north within each column. The format is used to exchange digital elevation models between terrain-building tools and visualization software, and is often distributed in a gzip-compressed .bt.gz form.
What are CAL files?
A CAL image file represents a monochrome bitmap image that uses the CALS raster image standard for storing graphics data. This standard was created in the 1980s by the US Department of Defence as a compressed interchangeable image format. CAL and CALS are extensions used for similar purposes.
Can reaConverter convert BT to CAL?
Yes! reaConverter instantly converts .bt to .cal with perfect quality preservation. With its batch processing feature, you can convert multiple files at once in just a few clicks. You can even convert images directly from Windows Explorer using the right-click menu — fast and convenient.
What is reaConverter used for?
reaConverter is a Windows converter for 800+ formats, GIS data among them. For BT to CAL it replaces the usual detour through QGIS, ArcGIS or ogr2ogr: add the files, pick the output format, and the whole batch converts offline. Surveyors, planners and engineering teams use it to pass data between GIS, CAD and everyday document formats.
Why choose offline conversion with reaConverter?
reaConverter is a software program that is used for offline files conversion. Your proprietary documents never leave your computer – essential for architects, engineers, healthcare and government contractors handling classified projects. Meets GDPR, HIPAA, CCPA, and corporate security policies by ensuring files never cross borders or third-party systems.
Can I convert BT to CAL online?
If you only need to convert a few BT files to CAL format, feel free to try our free online free online BT to CAL converter — perfect for small batches with no installation needed!
How can I turn BT files into CAL on my computer?
The best way to change BTs to CALs on your PC is to install a quality piece of software, such as reaConverter. This software is extremely efficient in managing a wide range of batch files conversions, including conversion from BT to CAL.
How can I automate BT to CAL files conversion?
reaConverter supports all the most useful automation features such as right-click сonversion and Watch Folders for the most efficient automated files conversion in any software of this type.
Is there a way to convert BT files to CAL using the command prompt?
reaConverter provides full access to all its features via Windows command line, including a high-performance command-line bt to cal converter for batch processing.
What else can I do with reaConverter?
Change format settingsCopy metadata (EXIF, IPTC)Convert CAD formatsSet manual file dateConvert medical images
Related conversions
Other ways to convert BT files, and other sources that convert to CAL.
