GAMMA Questions

Hello,
Those mk_* routines can be used for stacks of interferograms.
To filter and unwrap individual interferograms: adf2 and mcf are the
programs to use.

Use the defaults as a starting place. Generally use a low value of
exponent for adf2 (.4 as the max).

Best regards,
Charles

On 2026-08-04 16:44, Lucas Johnson wrote:

GAMMA QUESTIONS - UNWRAPPING: GUIDE FOR UNWRAPPING [1]

Lucas Johnson

I'm curious if there is a script or procedure that encapsulates many
of the steps for unwrapping differential interferograms in the GAMMA
software. It appears that mk_unw_2d and mk_adf2_2d might be the thing
i'm looking for? But I don't see them used in the examples that i have
found. Essentially I'm curious if you recommend these routines or if
the more granular functions from the demos (like mcf and similar) are
still the best practice.

Thanks!

- Lucas
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[1] https://dep1doc.gfz.de/boards/21/topics/695

Thank you! I do indeed want to process stacks of interferograms. In the mk_diff_2d function there's a def option described as follows: "a map of the linear deformation rate is available that matches the size of the differential interferogram it is specified by the def filename parameter, otherwise a "-" can be entered." I have a few questions:

1. What does "linear deformation rate" mean? Would that be the mean velocity in LOS direction? Or could it be the mean velocity magnitude (magnitude = sqrt(vx^2 + vy^2))?
2. What does mk_diff_2d do with this linear deformation rate? Does simulate a phase and use similarly to the topo-simulated phase?

Thank you!

- Lucas

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Hello,
See my answers below.
Best regards,
Charles

On 10.08.2026 23:49, Lucas Johnson wrote:

GAMMA Questions - Unwrapping: RE: recommendation for unwrapping procedures
<https://dep1doc.gfz.de/boards/21/topics/695?r=697#message-697>

/Lucas Johnson/

Thank you! I do indeed want to process stacks of interferograms. In the |mk_diff_2d| function there's a |def| option described as follows: /"a map of
the linear deformation rate is available that matches the size of the
differential interferogram it is specified by the def filename parameter,
otherwise a "-" can be entered./" I have a few questions:

1. What does "linear deformation rate" mean? Would that be the mean velocity
in LOS direction? Or could it be the mean velocity magnitude (|magnitude =
sqrt(vx^2 + vy^2)|)?

Differential interferometry from a single stack always is defines deformation in
the LOS direction.

2. What does |mk_diff_2d| do with this linear deformation rate? Does simulate
a phase and use similarly to the topo-simulated phase?

It calculates a temporal phase function that is determined from the LOS rate 
specified for each point in the differential interferogram.
(I think the LOS rate is specified in the units of meters/day).  In the script
you can see the underlying gamma software program that
calculates the simulated phase. See the documentation.

Thank you!

- Lucas

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