Basic MeerKAT reduction of the DEEP2 field

Prerequisites

Please ensure to first read Putting-together-a-basic-reduction-recipe and Available-parameters-for-a-execution-task-(cab)

Introduction

The dataset and interactive CASA 4.7 tutorial can be downloaded from DEEP2 100MHz 4 hour 16 antenna tutorial. The goal of this tutorial is to translate the interactive tutorial into a Stimela recipe. We may not use the exact same parameters and steps set out in the accompanying document of the original.

In this tutorial we will create a basic reduction recipe for the a MEERKAT array release 1.5 (16 antenna) observation of the so-called DEEP2 field (Mauch et al.). This includes the core antennae and outer-most antennae, with which we can form baselines up to ~7600m. To keep the size down I already averaged the data down conservatively both in time and in frequency and selected the first 4 hours of the observation data between 1 to 1.1 GHz.

In this tutorial we will iteratively develop our reduction recipe. Therefore we will extensively make use of the steps list parameter in the Recipe.run method at the bottom of the standard recipe.

Listobs and basic plotting

Lets start by inspecting the data. We will use the listobs task to inspect what data is available for our reduction. In its most basic form the task takes only the Measurement Set name ('vis' parameter). We begin by defining a most basic recipe. Please make the necessary adjustments to run with uDocker or Singularity if you so desire.

  1 import stimela
  2 
  3 INPUT="input"
  4 MSDIR="msdir"
  5 OUTPUT="output"
  6 
  7 recipe = stimela.Recipe("MEERKAT AR1.5 DEEP2 reduction",
  8                         ms_dir=MSDIR,
  9                         JOB_TYPE="docker")
 10 
 11 # basic data inspection
 12 recipe.add("cab/casa_listobs", "get_obsinfo", {
 13     "vis": "1491291289.1ghz.1.1ghz.4hrs.ms"
 14 }, input=INPUT, output=OUTPUT, label="view obs info")
 15 
 16 STEPS = [
 17     "view obs info"
 18 ]
 19 recipe.run(STEPS)