ValueError: Zero-size array to reduction operation maximum which has no identity during 'ion-filt'

[hillsonghimire]

While I tried running alos2App.py, I faced this issue in ion_filt step.
Here is the error message I got during the process.
I didn't face this issue while working with other datasets.

NOTE: I am using both Pds_ProductID="WBDR1.1__D" and so the error is noted, but when i use other category of ALOS-2 data say, Pds_ProductID="FBDR1.1__A, I do not get such issues.

2023-11-22 13:54:30,685 - isce.alos2insar.runIonUwrap - INFO - 
####################################################################################################
    runIonUwrap
----------------------------------------------------------------------------------------------------
####################################################################################################
Dumping the application's pickle object _insar to file  PICKLE/ion_unwrap
The remaining steps are (in order):  ['ion_filt', 'ion_correct', 'filt', 'unwrap', 'geocode', 'slc_mosaic', 'slc_match', 'dense_offset', 'filt_offset', 'geocode_offset']
Running step ion_filt

computing ionosphere
after adjustment:
Traceback (most recent call last):
  File "/home/gic/mambaforge/envs/isce2/bin/alos2App.py", line 1173, in <module>
    insar.run()
  File "/home/gic/mambaforge/envs/isce2/lib/python3.11/site-packages/isce/components/iscesys/Component/Application.py", line 142, in run
    exitStatus = self._processSteps()
                 ^^^^^^^^^^^^^^^^^^^^
  File "/home/gic/mambaforge/envs/isce2/lib/python3.11/site-packages/isce/components/iscesys/Component/Application.py", line 405, in _processSteps
    result = func(*pargs, **kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^
  File "/home/gic/mambaforge/envs/isce2/lib/python3.11/site-packages/isce/components/isceobj/Alos2Proc/Factories.py", line 40, in __call__
    return self.method(self.other, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/gic/mambaforge/envs/isce2/lib/python3.11/site-packages/isce/components/isceobj/Alos2Proc/runIonFilt.py", line 98, in runIonFilt
    ionos = computeIonosphere(lowerUnw, upperUnw, cor**corOrderAdj, fl, fu, adjFlag, 0)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/gic/mambaforge/envs/isce2/lib/python3.11/site-packages/isce/components/isceobj/Alos2Proc/runIonFilt.py", line 387, in computeIonosphere
    print('max phase difference: {}'.format(np.amax(unw_diff)))
                                            ^^^^^^^^^^^^^^^^^
  File "/home/gic/mambaforge/envs/isce2/lib/python3.11/site-packages/numpy/core/fromnumeric.py", line 2827, in amax
    return _wrapreduction(a, np.maximum, 'max', axis, None, out,
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/gic/mambaforge/envs/isce2/lib/python3.11/site-packages/numpy/core/fromnumeric.py", line 88, in _wrapreduction
    return ufunc.reduce(obj, axis, dtype, out, **passkwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
ValueError: zero-size array to reduction operation maximum which has no identity

Also my configuration file alos2App.xml looks is as:

<?xml version="1.0" encoding="UTF-8"?>
<alos2App>
    
  <component name="alos2insar">
      
    <property name="reference directory">./Pre/231009</property>
    <property name="secondary directory">./Post/231120</property>

    <property name="reference frames">[3500]</property>
    <property name="secondary frames">[3500]</property>

    <property name="starting swath">1</property>
    <property name="ending swath">5</property>

      
    <property name="geocode file list">[filt_*-*_*_*.int, filt_*-*_*_*.unw, filt_*-*_*_*_msk.unw]</property>
    <property name="use GPU">True</property>
  </component>
</alos2App>