"GARPOS" (GNSS-Acoustic Ranging combined POsitioning Solver) is an analysis tool for GNSS-Acoustic seafloor positioning.
Latest version is GARPOS v1.0.0 (Feb. 8. 2021)
Watanabe, S., Ishikawa, T., Yokota, Y., & Nakamura, Y. (2020). GARPOS: analysis software for the GNSS-A seafloor positioning with simultaneous estimation of sound speed structure, Front. Earth Sci. (https://doi.org/10.3389/feart.2020.597532).
Shun-ichi Watanabe, Tadashi Ishikawa, Yusuke Yokota, & Yuto Nakamura. (2020). GARPOS: Analysis tool for GNSS-Acoustic seafloor positioning (Version 1.0.0). Zenodo. https://doi.org/10.5281/zenodo.4522027
- Shun-ichi Watanabe
- Hydrographic and Oceanographic Department, Japan Coast Guard
- Website : https://www1.kaiho.mlit.go.jp/KOHO/chikaku/kaitei/sgs/index.html (in Japanese)
"GARPOS" is distributed under the [GPL 3.0] (https://www.gnu.org/licenses/gpl-3.0.html) license.
Please see Watanabe, S., Ishikawa, T., Yokota, Y., and Nakamura, Y., (2020) https://doi.org/10.3389/feart.2020.597532
- Python 3.7.3
- Packages NumPy, Scipy, Pandas, and Matplotlib are also required.
- Fortran 90 compiler (e.g., gfortran)
Environments under Anaconda for Linux is tested.
For the calculation of travel time, a Fortran90-based library is needed. For example, the library can be compiled via gfortran as,
gfortran -shared -fPIC -fopenmp -O3 -o lib_raytrace.so sub_raytrace.f90 lib_raytrace.f90
Path to the library should be indicated in "Settings.ini".
When using GARPOS, you should prepare the following files.
- Initial site-parameter file (e.g., *initcfg.ini)
- Acoustic observation data csv file
- Reference sound speed data csv file
- Settings file (e.g., Settings.ini)
"bin/solveSingleEpoch.py" is a driver code. Two observation epochs are stored in "sample" directory as demo data.
cd sample
./demo.sh
or run the program manually.
cd sample
# to solve position for each transponder (for epoch SAGA.1903)
solveSingleEpoch.py -i Settings-prep.ini -f initcfg/SAGA/SAGA.1903.kaiyo_k4-initcfg.ini -d demo_prep/SAGA
# to solve position for each transponder (for epoch SAGA.1905)
solveSingleEpoch.py -i Settings-prep.ini -f initcfg/SAGA/SAGA.1905.meiyo_m5-initcfg.ini -d demo_prep/SAGA
# to make the averaged array
makeFixCfg.py -d cfgfix --res_singles "demo_prep/SAGA/*res.dat"
# to solve in array-constraint condition (for epoch SAGA.1903)
solveSingleEpoch.py -i Settings-fix.ini -f cfgfix/SAGA/SAGA.1903.kaiyo_k4-fix.ini -d demo_res/SAGA
# to solve in array-constraint condition (for epoch SAGA.1905)
solveSingleEpoch.py -i Settings-fix.ini -f cfgfix/SAGA/SAGA.1905.meiyo_m5-fix.ini -d demo_res/SAGA
The following files will be created in the directory (specified with "-d" option).
- Estimated site-parameter file (*res.dat)
- Modified acoustic observation data csv file (*obs.csv)
- Model parameter list file (*m.p.dat)
- A posteriori covariance matrix file (*var.dat)
Please be aware of your storage when searching hyperparameters,
since it will create result files for all combinations of hyperparameters.
- drive_garpos (in garpos_main.py)
- parallelrun (in garpos_main.py)
- MPestimate (in mp_estimation.py)
- init_position (in setup_model.py)
- make_splineknots (in setup_model.py)
- derivative2 (in setup_model.py)
- data_correlation (in setup_model.py)
- calc_forward (in forward.py)
- corr_attitude (in coordinate_trans.py)
- calc_traveltime (in traveltime.py)
- calc_gamma (in forward.py)
- jacobian_pos (in forward.py)
- corr_attitude (in coordinate_trans.py)
- calc_traveltime (in traveltime.py)
- outresults (in output.py)
- MPestimate (in mp_estimation.py)
No. | Index | Description |
---|---|---|
00 | SET | Names of subset in each observation (typically S01, S02,...) |
01 | LN | Names of survey lines in each observation (typically L01, L02,...) |
02 | MT | ID of mirror transponder (should be consistent with Site-parameter file) |
03 | TT | Observed travel time |
04 | ResiTT | Residuals of travel time (observed - calculated) |
05 | TakeOff | Takeoff angle of ray path (in degrees, Zenith direction = 180 deg.) |
06 | gamma | Correction term setting in the observation equations |
07 | flag | True: data of this acoustic shot is not used as data |
08 | ST | Transmission time of acoustic signal |
09 | ant_e0 | GNSS antenna position (eastward) at ST |
10 | ant_n0 | GNSS antenna position (northward) at ST |
11 | ant_u0 | GNSS antenna position (upward) at ST |
12 | head0 | Heading at ST (in degree) |
13 | pitch0 | Pitch at ST (in degree) |
14 | roll0 | Roll at ST (in degree) |
15 | RT | Reception time of acoustic signal |
16 | ant_e1 | GNSS antenna position (eastward) at RT |
17 | ant_n1 | GNSS antenna position (northward) at RT |
18 | ant_u1 | GNSS antenna position (upward) at RT |
19 | head1 | Heading at RT (in degree) |
20 | pitch1 | Pitch at RT (in degree) |
21 | roll1 | Roll at RT (in degree) |
22 | dV0 | Sound speed variation (for dV0) |
23 | gradV1e | Sound speed variation (for east component of grad(V1)) |
24 | gradV1n | Sound speed variation (for north component of grad(V1)) |
25 | gradV2e | Sound speed variation (for east component of grad(V2)) |
26 | gradV2n | Sound speed variation (for north component of grad(V2)) |
27 | dV | Correction term transformed into sound speed variation (gamma x V0) |
28 | LogResidual | Actual residuals in estimation (log(TT) - log(calculated TT) |
*Indices #04-#07, #22-#28 will be updated after the estimation.