{ "cells": [ { "cell_type": "markdown", "id": "8ba3865b-b142-4842-ba34-7773c5de62d2", "metadata": {}, "source": [ "# How to: Jackknife Measurement Sets\n", "\n", "This tutorial explains how to jackknife measurement sets (ms-files), particularly for ALMA data, to create observation-specific noise realizations. We will use the `jackknify` package to handle ms-files, split them, and image the visibilities. \n", "\n", "### Step 1: Download Example Data\n", "First, download an example measurement set from [this link](https://drive.google.com/file/d/11933cHM2kpqRG_E2BdlQ81FHRWmyye3i/view?usp=sharing). After downloading, unzip the file and note the directory where you store it for future reference." ] }, { "cell_type": "markdown", "id": "0d1fc8a7-6275-48c4-a64c-0e99d8b25ed2", "metadata": {}, "source": [ "### Step 2: Initializing\n", "To start using the `jackknify` package, we need to initialize the measurement set so that `jackknify` can interface with CASA." ] }, { "cell_type": "code", "execution_count": 1, "id": "a26759ef-8147-477f-8884-9691d0a5df27", "metadata": {}, "outputs": [], "source": [ "import jackknify" ] }, { "cell_type": "code", "execution_count": 2, "id": "5c75dafb-68cb-4e43-87b7-192e3f1c2617", "metadata": { "tags": [] }, "outputs": [], "source": [ "#initilaize\n", "tool = jackknify.Jack(fname = '../../data/Glass-z13.ms', # The file name of the visibilities, \n", " outdir = '../../output/', #the directory to save the outputs in\n", " fields = ['3'], # Each visibility can have multiple fields, \n", " spws = [['0']], # and each field can have multiple spws,\n", " band = 'Band7', # Band of the observation,\n", " array = 'C7', # which configuration the observation are taken in,\n", " )" ] }, { "cell_type": "markdown", "id": "ec1a048d-3e9a-4170-82e4-01981c864e11", "metadata": {}, "source": [ "### Step 3: Create a Jackknifed Measurement Set\n", "To create a jackknifed measurement set, simply run the following code. \n", "This will generate the jackknifed measurement set, which you can then use for further analysis or imaging." ] }, { "cell_type": "code", "execution_count": 3, "id": "6620c09e-6489-451b-bee5-8fb5332d2407", "metadata": {}, "outputs": [ { "name": "stderr", "output_type": "stream", "text": [ " 0%| | 0/1 [00:00