---
name: "phasefilt"
section: "1"
platform: "linux"
package: "gmtsar-core"
version: "6.5+ds-3"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/phasefilt"
---

# phasefilt(1)

phasefilt

## NAME

phasefilt - phasefilt

## DESCRIPTION

This program is part of GMTSAR.

-

  phasefilt \[GMTSAR\] - Apply adaptive non-linear phase filter

-

  USAGE:

phasefilt **-imag** imag.grd **-real** real.grd \[-alpha alpha\]\[-psize size\]\[-amp1 amp1.grd **-amp2** amp2.grd\]\[-diff\]\[-v\]

-

  applies Goldstein adaptive filter to phase \[output: filtphase.grd\] or applies modified Goldstein adaptive filter to phase \[output: filtphase.grd, corrfilt.grd\]

**-imag** \[required\] GMT format file of imaginary component **-real** \[required\] GMT format file of real component **-alpha**  exponent for filter - usually between 0.0 and 1.5 (0.0 should not filter).

- default: 0.5

  \[Goldstein filter\] (anything above 1.0 may be excessive)

-

  alpha \< 0 will set alpha = (1 - coherence) \[modified Goldstein\]

**-psize**  patch size for filtering. Must be power of two.

-

  default: 32

**-amp1**           GMT format file of amplitude image of image 1. Needed (and applies) modified filter. **-amp2**           GMT format file of amplitude image of image 2. Needed (and applies) modified filter. **-diff**           Calculate difference between input phase and output phase. **-complex\_out**    Write out filtered real and imaginary (filtphase\_real.grd and filtphase\_imag.grd) **-v**              Verbose. **-debug**  Debug.

example: phasefilt **-imag** imag.grd **-real** real.grd **-alpha** 0.5

-

  USAGE:

phasefilt **-imag** imag.grd **-real** real.grd \[-alpha alpha\]\[-psize size\]\[-amp1 amp1.grd **-amp2** amp2.grd\]\[-diff\]\[-v\]

-

  applies Goldstein adaptive filter to phase \[output: filtphase.grd\] or applies modified Goldstein adaptive filter to phase \[output: filtphase.grd, corrfilt.grd\]

**-imag** \[required\] GMT format file of imaginary component **-real** \[required\] GMT format file of real component **-alpha**  exponent for filter - usually between 0.0 and 1.5 (0.0 should not filter).

- default: 0.5

  \[Goldstein filter\] (anything above 1.0 may be excessive)

-

  alpha \< 0 will set alpha = (1 - coherence) \[modified Goldstein\]

**-psize**  patch size for filtering. Must be power of two.

-

  default: 32

**-amp1**           GMT format file of amplitude image of image 1. Needed (and applies) modified filter. **-amp2**           GMT format file of amplitude image of image 2. Needed (and applies) modified filter. **-diff**           Calculate difference between input phase and output phase. **-complex\_out**    Write out filtered real and imaginary (filtphase\_real.grd and filtphase\_imag.grd) **-v**              Verbose. **-debug**  Debug.

example: phasefilt **-imag** imag.grd **-real** real.grd **-alpha** 0.5