fetch GNSS time-series

[yunjunz]

Function(s) to fetch the GNSS time-series with documentation on the correction levels. This should include two functions:

• search the available GNSS sites
• for each site, download and read the time-series data

1 - search_gnss()

Search the list of available GNSS sites given a certain set of criteria.

Inputs

• SNWE - list of 4 floats in (south, north, west, east) in degrees
• start_datetime - datetime object
• end_datetime - datetime object
• solution_provider - str, GNSS solution provider, e.g. UNR, JPL, SOPAC
• kwargs - dict, usability metric, e.g. ?
  • min_num_observation
  • fraction

Outputs

• site_names - list of str, the list of names/IDs of available GNSS sites
• site_lats - list of float, the list of latitudes of available GNSS sites
• site_lons - list of float, the list of longitudes of available GNSS sites

Status [done]

• mintpy.objects.gnss.search_gnss() supports the UNR / SIDESHOW / ESESES solutions.

2 - get_gnss_displacement()

For each GNSS site, download the data file and read them. The output should be one common format as defined below, regardless of the solution providers.

Inputs

• site_name - str, GNSS site name/ID
• start_datetime - datetime object
• end_datetime - datetime object
• solution_provider - str, GNSS solution provider, e.g. UNR, JPL, SOPAC

Outputs

• site_lat/lon - float, latitude and longitude of the GNSS site in degree
• site_hgt - float, height of the GNSS site in meter
• E/N/U time-series - 1D np.ndarray in float32, displacement time-series in meters
• E/N/U time-series uncertainty (STD) - 1D np.ndarray in float32, uncertainty of displacement time-series in meters
• reference_frame - str
• correction_level - str or list of str [require more detailed definitions/descriptions]
• step_time_coseismic - list of datetime objects, times with co-seismic jumps
• step_time_antenna - list of datetime objects, times with antenna changes/maintainances.

Status [in progress]

• mintpy.objects.gnss.py supports UNR / SIDESHOW / ESESES solutions.

Missing functionalities

• correction_level - str or list of str [require more detailed definitions/descriptions]

[dbekaert]

Interest from Adrian Borsa @hydrogeodesy