prx

prx reads a RINEX 3.05 observation file and outputs a CSV file of the following format

# {"approximate_receiver_ecef_position_m": [4627852.5264, 119640.514, 4372994.8358], "input_files": [{"name": "TLSE00FRA_R_20240011200_15M_01S_MO.rnx", "murmur3_hash": "bbc2db05fb5d0384ac26e9b9c0236f69"}, {"name": "BRDC00IGS_R_20240010000_01D_MN.rnx", "murmur3_hash": "f7df97043856eb0e57b8e1589c061043"}], "prx_git_commit_id": "ee48104e3d96098a7dc945f7af8ae8484fcd232a", "processing_start_time": "2024-10-02 17:21:08.7285603", "processing_time": "0 days 00:00:19.708024"}
time_of_reception_in_receiver_time,sat_clock_offset_m,sat_clock_drift_mps,sat_pos_x_m,sat_pos_y_m,sat_pos_z_m,sat_vel_x_mps,sat_vel_y_mps,sat_vel_z_mps,ephemeris_hash,frequency_slot,relativistic_clock_effect_m,sagnac_effect_m,tropo_delay_m,sat_code_bias_m,carrier_frequency_hz,iono_delay_m,sat_elevation_deg,sat_azimuth_deg,rnx_obs_identifier,C_obs_m,D_obs_hz,L_obs_cycles,LLI,S_obs_dBHz,constellation,prn
2024-01-01 12:00:00.000000,57153.224736,-0.018397,21838606.222023,36012172.441686,-1479022.231769,-3.184508,4.675864,-0.920381,2245131395643944762,1.000000,-0.668490,-39.902407,10.053189,0.149896,1561098000.000000,-15.044328,13.082414,115.281248,2I,40176280.391000,-14.730000,209208378.723000,,35.400000,C,05
2024-01-01 12:00:00.000000,57153.224736,-0.018397,21838606.222023,36012172.441686,-1479022.231769,-3.184508,4.675864,-0.920381,2245131395643944762,1.000000,-0.668490,-39.902407,10.053189,0.000000,1268520000.000000,-22.784446,13.082414,115.281248,6I,40176273.273000,-11.969000,169998932.830000,,36.900000,C,05
2024-01-01 12:00:00.000000,57153.224736,-0.018397,21838606.222023,36012172.441686,-1479022.231769,-3.184508,4.675864,-0.920381,2245131395643944762,1.000000,-0.668490,-39.902407,10.053189,-2.728111,1207140000.000000,-25.160417,13.082414,115.281248,7I,40176276.934000,-11.391000,161773185.396000,,38.400000,C,05
...

In addition to the observation values extracted from the RINEX file, the rows of the CSV contain the corresponding satellite position and speed at the time of transmission as well as relativistic effects, broadcast group delays, broadcast ionosphere delays etc.

Running prx

From the prx repository root, run

poetry env use 3.12
poetry install
poetry shell
python src/prx/main.py --observation_file_path <path_to_rinex_file> 

You might have to add <path to prx root>/src/prx to your PYTHONPATH environment variable if you run into import errors.

How we manage python version and dependencies

We use poetry to make sure every developer and user of prx runs the same python version and the same set of dependencies such as numpy and pandas. Poetry reads pyproject.toml, resolves dependencies and writes the result to poetry.lock, which is the file used when running poetry install.

To install poetry see https://python-poetry.org/docs/#installation

To create the virtual environment, run poetry install in the prx repository root. This has to be run every time an update to the pyproject.toml and poetry.lock files is done (for example, after a git pull)

Jumping into the virtual environment

Run poetry shell to activate the virtual environment in a terminal.

Using the poetry virtual environment in PyCharm

Run poetry env info -p to find the path of the virtual environment, which we'll call <venv-path> Under File -> Settings -> Project -> Python Interpreter add <venv-path> as python interpreter. If you run into problems, try <venv-path>/bin/python on Linux or <venv-path>\Scripts\python.exe on Windows.

Add packages to poetry

Let's say you wrote some code that uses import new_package. To have new package added (what you otherwise would use pip or some other package manager for), run

poetry add new_package

Poetry will resolve dependencies - i.e. figure out which is the latest version of new_package that is compatible with our virtual environment - and add it to pyproject.toml and poetry.lock.

Testing

After poetry shell

Run pytest in the prx repository root to run all tests. Run pytest -x to stop after the first test that fails. Run pytest -k "my_test" to run a specific test Run pytest ---durations=10 to run all tests and have pytest list the 10 longest running tests.

Coding style

We use https://google.github.io/styleguide/pyguide.html as our python style guide.

Acronyms

See the Rinex 3.05 spec, page 5, for a list of most acronyms used in the code. Those not covered by the RINEX spec are listed below.

Acronym	Long Form
PRX	Preprocessed Rinex