Originally published at: 🛰️ Discover Phase Linking for InSAR Processing in SNAP! – STEP
Interested in improving InSAR analysis over distributed scatterers? Two new resources introduce the Phase Linking approach in the SNAP Microwave Toolbox, combining practical guidance with an explanation of the underlying concepts. 
InSAR Phase Linking – Hands-on Tutorial Follow a step-by-step workflow using Sentinel-1 data to improve coherence over natural surfaces and map earthquake-related ground…
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Title: gpt: “Unknown operator ‘PhaseLinking’” in SNAP 14.0.2, but the operator exists in the Microwave Toolbox jar and in the SNAP GUI
System: SNAP 14.0.2 on Windows, Java 21.0.6 (gpt --diag: SNAP Release version 14.0.2).
Hello @diana_harosa, great work on the release of SNAP 14.
I have tried the Phase Linking but encountered an issue.
The Phase Linking operator (Radar > Interferometric > Phase Linking) is available in the SNAP desktop application and in Graph Builder, but gpt does not know it:
gpt.exe PhaseLinking -h
Unknown operator ‘PhaseLinking’.
What I checked:
- C:\Program Files\esa-snap\microwavetbx\modules\eu-esa-microwavetbx-sar-op-insar.jar (425144 bytes, dated 13/8/2026) contains eu/esa/sar/insar/gpf/PhaseLinkingOp.class and PhaseLinkingOp$Spi.class, plus the phaselinking/ package (KSSelector, EVDEstimator, …).
- META-INF/services/org.esa.snap.core.gpf.OperatorSpi in that jar lists eu.esa.sar.insar.gpf.PhaseLinkingOp$Spi.
- There are no InSAR jars under my user folder (.snap), only in Program Files.
- gpt -h lists Demodulate, StampsExport and MultiMasterInSAR from the same jar, but NOT PhaseLinking, SBASInversion or EmpiricalTropoCorrection, although all three are also in the same services file.
The operator is installed and registered in the jar, but gpt does not load it. Is this a known problem in 14.0.2, and is there a fix or a workaround for gpt (command line / batch processing)?
Regards.
Dear Fakhrul,
I did a quick check on my SNAP installation, and PhaseLinking appears in the list of available GPT operators:
Also, running gpt.exe PhaseLinking -h successfully displays the operator’s help:
This suggests that the operator is accessible through GPT, at least in my installation.
Have you tried running gpt.exe directly from the bin directory of your SNAP installation? If that still doesn’t work, the issue might be related to an inconsistent SNAP installation. You could try reinstalling the module updates or, if that doesn’t resolve the issue, reinstalling SNAP and checking whether the operator is then correctly recognized by GPT.