GNATSS is an open-source software for processing Global Navigation Satellite Systems - Acoustic (GNSS-A) data for seafloor horizontal positioning. The software is a redevelopment of existing FORTRAN codes and shell scripts developed by C. David Chadwell for processing data including measurements made with Wave Gliders. Existing code, which includes proprietary routines, is developed and maintained by John DeSanto.
This software is available via PyPI, the Python Package Index
You can install the software with pip directly by running the following command:
pip install gnatssOnce the software is installed, you should be able to get to the GNATSS Command
Line Interface (CLI) using the command gnatss. For example: gnatss --help,
will get you to the main GNSS-A Processing in Python help page.
Usage: gnatss [OPTIONS] COMMAND [ARGS]...
GNSS-A Processing in Python
╭─ Options ───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╮
│ --version Show version and exit. │
│ --install-completion Install completion for the current shell. │
│ --show-completion Show completion for the current shell, to copy it or customize the installation. │
│ --help Show this message and exit. │
╰─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯
╭─ Commands ──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╮
│ run Runs the full pre-processing routine for GNSS-A │
╰─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯
Currently there's a single command available in the CLI, run, which will run
the full pre-processing routine for GNSS-A. You can retrieve the helper text for
this command by running gnatss run --help.
Usage: gnatss run [OPTIONS] CONFIG_YAML
Runs the full pre-processing routine for GNSS-A
Note: Currently only supports 3 transponders
╭─ Arguments ─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╮
│ * config_yaml TEXT Custom path to configuration yaml file. **Currently only support local files!** [default: None] [required] │
╰─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯
╭─ Options ───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╮
│ --extract-dist-center --no-extract-dist-center Flag to extract distance from center from run. [default: extract-dist-center] │
│ --extract-process-dataset --no-extract-process-dataset Flag to extract process results. [default: extract-process-dataset] │
│ --outlier-threshold FLOAT Threshold for allowable percentage of outliers before raising a runtime error. │
│ [default: None] │
│ --distance-limit FLOAT Distance in meters from center beyond which points will be excluded from solution. Note │
│ that this will override the value set as configuration. │
│ [default: None] │
│ --residual-limit FLOAT Maximum residual in centimeters beyond which data points will be excluded from solution. │
│ Note that this will override the value set as configuration. │
│ [default: None] │
│ --qc --no-qc Flag to plot residuals from run and store in output folder. [default: qc] │
│ --from-cache --no-from-cache Flag to load the GNSS-A Level-2 Data from cache. [default: no-from-cache] │
│ --remove-outliers --no-remove-outliers Flag to execute removing outliers from the GNSS-A Level-2 Data before running the solver │
│ process. │
│ [default: no-remove-outliers] │
│ --run-all --no-run-all Flag to run the full end-to-end GNSS-A processing routine. [default: run-all] │
│ --solver --no-solver Flag to run the solver process only. Requires GNSS-A Level-2 Data. [default: no-solver] │
│ --posfilter --no-posfilter Flag to run the posfilter process only. Requires GNSS-A Level-1 Data Inputs. │
│ [default: no-posfilter] │
│ --help Show this message and exit. │
╰─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯Currently the pre-processing routine have been tested to only supports 3 transponders, but this will be expanded in the future.
The run command takes in a configuration yaml file, which is used to configure
the pre-processing routine. You will need to provide a config yaml file when
calling gnatss run.
Here's a sample configuration yaml file:
site_id: SITE #Site Identifier
campaign: Region #Geographical region/Subduction Zone
time_origin: YYYY-MM-DD 00:00:00 #Time of survey
array_center:
lat: xx.yyyy #decimal latitude
lon: xxx.yyyy #decimal longitude
transponders: # list out all transponder and info, each entry is a different transponder (default: 3 transponders)
- lat: xx.yyyyyyyyyy #decimal latitude
lon: xx.yyyyyyyyyy #decimal longitude
height: -zzzz.zz #transponder depth (m, positive up)
internal_delay: t.tttt #Transponder Turn-Around Time (s)
sv_mean: vvvv.vvv #Estimate of mean sound velocity (m/s)
- lat: xx.yyyyyyyyyy #decimal latitude
lon: xx.yyyyyyyyyy #decimal longitude
height: -zzzz.zz #transponder depth (m, positive up)
internal_delay: t.tttt #Transponder Turn-Around Time (s)
sv_mean: vvvv.vvv #Estimate of mean sound velocity (m/s)
- lat: xx.yyyyyyyyyy #decimal latitude
lon: xx.yyyyyyyyyy #decimal longitude
height: -zzzz.zz #transponder depth (m, positive up)
internal_delay: t.tttt #Transponder Turn-Around Time (s)
sv_mean: vvvv.vvv #Estimate of mean sound velocity (m/s)
travel_times_variance: 1e-10 #Default value
travel_times_correction: 0.0 #Default value
transducer_delay_time: 0.0 #Default value
# Main input files
input_files:
travel_times: #Assume Chadwell format, (Time at Ping send [DD-MON-YY HH:MM:SS.ss], TWTT1 (microseconds), TWTT2, TWTT3, TWTT4), TWTT=0 if no reply
path: /path/to/pxp_tt
# Posfilter configuration
posfilter:
export:
full: false #false for only required fields, true to include optional RPH value and uncertainties
atd_offsets:
forward: 0.0053 #Value for SV3 Wave Glider
rightward: 0 #Value for SV3 Wave Glider
downward: 0.92813 #Value for SV3 Wave Glider
input_files:
novatel:
path: /path/to/file #File with INSPVAA strings
novatel_std:
path: /path/to/file #File with INSSTDEVA strings
gps_positions: #Assume Chadwell format, (j2000 seconds, "GPSPOS" string, ECEF XYZ coordinates (m), XYZ Standard Deviations)
path: /path/to/GPS_POS_FREED #File path to antenna positions, use wildcards ** for day-separated data
# Solver configuration
solver:
reference_ellipsoid: #These values should be constant unless the Earth changes
semi_major_axis: 6378137.000
reverse_flattening: 298.257222101
gps_sigma_limit: 0.05 #Uncertainty threshold for transducer positions, data with larger uncertainties ignored
std_dev: true #true=standard deviation, false=covariance, probably deprecated
geoid_undulation: xx.yy #Geoid height in m
bisection_tolerance: 1e-10 #Do not change
harmonic_mean_start_depth: -4.0 #Shallowest water depth for calculating mean soundvelocity from CTD data
input_files:
sound_speed: #Assume 2-column text file with depth (m), sound velocity (m/s)
path: /path/to/file
# deletions: # Path to deletns.dat deletions file used by Chadwell code as well
# path: ../tests/data/2022/NCL1/deletns.dat
#gps_solution: #Path to pre-processed input data in standard GNSS-A data format, this skips the Posfilter step
# path: ../gps_solution.csv
#quality_control:
# path: /Users/lsetiawan/Repos/SSEC/offshore-geodesy/tests/data/2022/NCL1/quality_control.csv
# Output configuration
output: # Directory path to output directory
path: /path/to/output/Please refer to our Contributing Guide on how to setup your environment to contribute to this project.
Thanks to our contributors so far!
This has a BSD-3-Clause License, which can be found here.