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Getting data from TART

Each telescope can be queried for data using the telescope API (API)

Authentication

One doesn't need a login to capture data from a TART telescope.

Using the API directly​

The authentication is only need for API requests that modify the telescope properties (like uploading calibration gains and phases).THe API for the telescope is documented online (https://tart.elec.ac.nz/signal/doc/) and shows the restful API calls that can be made. To get imaging data try the (https://tart.elec.ac.nz/signal/doc/#api-Imaging-get_latest_vis)

    wget -O test.json  https://tart.elec.ac.nz/signal/api/v1/imaging/vis

This will download the latest visibilties into a file called test.json

Using the tart_tools package​

You can install the tart_tools python package which will give you some command line tools to work with the TART telescope.

pip3 install tart_tools

Creating a measurement set​

You can install the tart2ms python package which will give you some command line tools to work with the measurement sets

pip3 install tart2ms

Download a single snapshot

tart2ms --ms obs.ms --api https://tart.elec.ac.nz/signal

Download 1 minute worth of visibilities, and combine them into a single observation

tart2ms --ms signal1.ms --vis vis_2023-11-13_07_28_34.576476.hdf --rephase obs-midpoint --single-field

You can create an image using the disko package

disko --ms signal1.ms --SVG --fov 170deg --res 1deg --lasso --alpha 0.05 --healpix

From S3 bucket​

Visibility and Raw data can also be downloaded from the S3 Cache (most recent 30days only).

Install requirements​

pip3 install minio tqdm

Fetch via MinIO​

import os
from tqdm import tqdm
from minio import Minio

MINIO_API_HOST = "s3.max.ac.nz"
BUCKET_NAME = "tart-hdf"

# prefix = 'rhodes/raw/2022/'
# prefix = 'rhodes/vis/2022/'
# prefix = 'signal/raw/2022/'
prefix = 'signal/vis/2022/'

output = 'downloads/'

limit_last_10 = -10     # Only fetch the last 10 entries files


if __name__ == "__main__":
    if not os.path.exists(output):
        os.mkdir(output)

    client = Minio(MINIO_API_HOST, secure=True)
    objects = client.list_objects(BUCKET_NAME, prefix=prefix, recursive=True)


    for item in tqdm(list(objects)[limit_last_10:]):
        fname_out = f'{output}{item.object_name}'
        client.fget_object(BUCKET_NAME, item.object_name, fname_out)
        print(fname_out)

Follow up by creating a measurement set from selected or all hdf files

tart2ms  --hdf downloads/*/vis/*/*/*/*.hdf --telescope_name 'kat-7'