Timeseries interpretation

[Wahdan Achmad Syaehuddin]

Hi All,

Sorry for the basic question. I want to make sure of my interpretation of the time series output. Is the displacement value for each date relative to reference date, the date before, or difference between two inteferogram acquisitions? Thank you.

Best,
Wahdan

[Yuan-Kai Liu]

The answer is relative to the reference date you set.

The time series are generated by calling this code internally in smallbaselineApp.py:

 ifgram_inversion.py

You can see from the --help of it

 ifgram_inversion.py -h

  --ref-date REF_DATE   Reference date, first date by default.

You will see the setting also in the config file (smallbaselineApp.cfg, which is your default value if you run smallbaselinApp.py)

########## 9.2 reference_date
## Reference all time-series to one date in time
## reference: Yunjun et al. (2019, section 4.9)
## no     - do not change the default reference date (1st date)
mintpy.reference.date = 20150426   #[reference_date.txt / 20090214 / no], auto for reference_date.txt