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Open a DZT file online

A .DZT file is the raw recording of a GSSI ground penetrating radar. GPRviewer opens it right in your browser, without RADAN, installation or licence: drop the file and the radargram appears in seconds.

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What is a DZT file?

DZT is the native format of GSSI control units and antennas: SIR 3000 and SIR 4000, UtilityScan and UtilityScan DF, StructureScan Mini XT and LXT, FLEX NX, NX25 and NX15, Palm… It holds a header (antenna, time range in nanoseconds, samples, scans per metre, dielectric constant) followed by the radar traces, one or two channels depending on the antenna.

It often comes with a .DZX file (marks, settings), which GPRviewer also reads when it sits in the same folder.

Open a DZT file in 3 steps

Go to gprviewer.com and create a free account (e-mail address).
Drop your .DZT file onto the window, or click “Open”. You can open several files or a whole folder at once.
The radargram appears with distance and depth scales. Adjust gain, colour map and dielectric constant, then export a PNG image.

Radargram from a DZT file opened in GPRviewer, with distance and depth scales

What you can do for free

Read .DZT files, including dual-frequency antennas (two channels).
12 colour maps, zoom from ×0.25 to ×4, live A-scan trace.
Depth calibration and dielectric constant setting.
Background removal and depth cropping.
PNG export of the radargram.

Going further

The Pro version adds rebar picking (manual or AI-assisted), measurement, hyperbola fitting, interface tracing, frequency filters, migration, file merging, C-Scan plan view and 3D view.

Automatic rebar picking on a reinforced concrete radargram

Your files stay yours

Radar files are never kept on our servers: they stay on your computer. Only your settings and picks can be saved, in a .mds file next to the radargram.

Frequently asked questions

Do I need RADAN to open a DZT file?

No. GPRviewer reads the GSSI DZT format directly in the browser, without RADAN or any other software.

Is it really free?

Yes: opening files, display, gain, colour maps, depth calibration and PNG export are free with a simple account. Advanced analysis tools are part of the Pro version.

Which radars are supported?

GSSI systems that record .DZT files (SIR 3000, SIR 4000, UtilityScan, UtilityScan DF, StructureScan Mini XT/LXT, FLEX NX, NX25, NX15…) and Compass files (.nx).

Can I open a DZT file on a Mac or a tablet?

Yes. GPRviewer runs in any recent browser (Chrome, Edge, Firefox, Safari) on Windows, macOS, Linux and tablets.

Is my data uploaded to the internet?

Radar files are not kept on our servers. They stay on your computer.