A python script for processing optical comb data useful for Time&Frequency science in the optical domain. The script outputs data in the ROCIT format, useful for comparison using optical fibre links, developed for the EMPIR project ROCIT and for the European Partnership on Metrology Project TOCK. See also:
Development is at
Documentation is available at https://super-auto-comb.readthedocs.io
This package is not yet on Pypi.
This project is managed by Poetry and requirements can be found in the pyproject.toml file.
Install using pipx directly from Github:
$ pipx install git+https://github.com/INRIM/super-auto-comb.git
Verify the installation and the available Command Line Interface (CLI) arguments with:
$ super-auto-comb --help
To simplify the inputs of CLI arguments, prepare a super-auto-comb.txt file in the folder where you want to process comb data similar to:
do = [my_do1, my_do2]
start = 2023-02-24
stop = 2023-04-29
dir = ./Outputs
fig-dir = ./Outputs/Figures
comb-dir = your-path-to-comb-data
setup-dir = your-path-to-comb-setup-files
and invoke $ super-auto-comb to process the data.
For repeating data processing day-after-day you can run $ super-auto-comb --auto to process the data.
The appropriate start date will be read/saved in the file super-auto-last.txt for subsequent use.
Super-auto-combs read files that describe designed oscillators (DO) and combs, and how these setups changed over time. For both DOs and combs information are stored line by line. Each line should start with a datetime in ISO format (e.g., 2021-10-28T16:20:21, local time is ok). It is intended that the data on the line applies from that date to the date on the next line (if any). Changes should be tracked by adding more lines. See the tests/samples folder for examples. If super-auto-comb is invoked by super-auto-comb --do my_do, it will look for a file my_do.dat. If this file has my_comb under the comb column, super-auto-comb will then look for a my_comb.dat file.
The columns of these files should be:
| Column name | Data type | Description |
|---|---|---|
| datetime | ISO | Datetime of the change |
| maser | string | Reference maser |
| frep | float | Repetition rate in Hz |
| f0 | float | Offset frequency in Hz (with sign) |
| counter_f0 | int | Counter channel counting f0 |
DO files are more complex, and should contain all information required to transform from counted frequencies to absolute frequencies, supplemented by the details of the measurement on the counter (divided in counter1 and counter2 for double counting)
| Column name | Data type | Description |
|---|---|---|
| datetime | ISO | Datetime of the change |
| comb | string | Comb used for the measurement comb1 or comb2 |
| physical | string | Physical oscillator |
| nominal | string | Nominal frequency in Hz (should be a string in quotes, e.g. '518_295_836_590_863.6') |
| kscale | float | Frequency scaling (typically 1, 2 in case of SHG) |
| foffset | float | Offset frequency in Hz from the counted beatnote |
| N | int | comb tooth |
| fbeat_sign | int | sign of the physical beatnote |
| f0_scale | int | scaling of f0 (typically 1, 2 for measurements with visible branch) |
| counter1 | int | Counter channel |
| flo1 | float | Local oscillator frequency in Hz (with sign)) |
| min1 | float | Minimum acceptable counted frequency |
| max1 | float | Maximum acceptable counted frequency |
| counter2 | int | Counter channel |
| flo2 | float | Local oscillator frequency in Hz (with sign)) |
| min2 | float | Minimum acceptable counted frequency |
| max2 | float | Maximum acceptable counted frequency |
The math is:
-
$f_N = f_{rep} N + f_0 \times scale_{f_0}$ -
$f_{beat} = sign_{beat} \times |f_{counter} + f_{lo}|$ -
$f_{abs} = k_{scale} \times (f_N + f_{beat}) + f_{offset}$
Data input files are expected to be generated by a K+K counter with names such as 220321_1_Frequ.txt.
This work has received funding from the European Partnership on Metrology, co-financed by the European Union’s Horizon Europe Research and Innovation Programme and by the Participating States, under grant number 22IEM01 TOCK.
(c) 2023-2024 Marco Pizzocaro - Istituto Nazionale di Ricerca Metrologica (INRIM)