GBT
Remote Observing Training for UAT
June 19-21, 2019
Thank you for your
interest in learning how to observe with the GBT. Since we have a busy week of UAT
activities to do along with the training, you will need to do some work before
you arrive.
Our schedule for the week is as follows:
Wednesday, June 19
16:30-17:00: Lecture on GBT observing
17:30-18:30: GBT Drift Scan observing in teams
Thursday, June 20
19:00-23:00: GBT Observations of LSB galaxies
At the end of the week, you will be familiar
with
1.
how to
prepare a GBT observation,
2.
how to
conduct a GBT observation, and
3.
how to
reduce GBT data.
Before you arrive:
á
Read
the GBT Proposer's Guide, particularly Section 5.
á
Familiarize
yourself with GBT Observer's Guide, particularly Section 6.2.4, 6.3, and
6.7.
á
Take a
look at the Observer Training Videos, particularly those on Astrid Scheduling
Blocks.
á
Use
these resources to complete the attached Scavenger Hunt.
á
Resources
To observe with
the GBT, there are three pieces of software you need to be at least somewhat
familiar with. They are
1.
Astrid: This is the program that you use to
observe and monitor your observations in real time.
2.
Cleo: This package has many useful utilities
for monitoring the state of the GBT and the signal path, planning your
observations, and communicating with the telescope operator.
3.
GBTIDL: This is the software package for
reducing GBT spectral line data.
There are numerous
resources available to learn about Astrid & Cleo and to plan your GBT
observations as well:
1.
GBT
Proposers' Guide: This document
describes the capabilities of the GBT and is a good resource both for getting
familiar with the telescope and writing proposals.
2.
GBT
Observers' Guide: This document
describes almost everything you need to know to prepare for observing and to
actually observe. It tells you how
to run Astrid & Cleo; how to write scheduling blocks and associated
observing files; the capabilities of different backends
and specialized observing modes; and strategies for planning your
observations.
3.
GBTIDL: Documentation for GBTIDL tasks can
generally be found via a Google search, but you can check out this webpage for
an overview and a link to the Users' Guide.
Otherwise, you can find
detailed descriptions of all the code in the GBTIDL Reference Manual.
5.
When
doing remote observing, the following webpage is an excellent resource with
step-by-step instructions for how to connect to the control computers: https://science.nrao.edu/facilities/gbt/observing/remote-observing-with-the-gbt Observing Training Scavenger Hunt The following
questions will primarily draw on the online resources, the GBT Proposer's Guide
and the GBT Observer's Guide. 1.
In
order to determine how much observing time you need to detect a source, you
need to know the Tsys and Gain of the GBT
L-band receiver. What are
they? You also need to pick a
frequency resolution. What mode of
VEGAS would you choose to observe HI in a galaxy? What frequency resolution and bandwidth
will it provide? 2.
You
can find an example configuration file for VEGAS observations at http://www.gb.nrao.edu/~dpisano/example.config.
A number of parameters: restfreq, bandwidth, nchan, and vegas.subband, have been left blank. Using the values for the mode you picked
in question 1, how would you complete this configuration file? 3.
The example.config file above has swmode='tp', what does this mean? Do you think you would you use this for
position-switched or frequency-switched observations? 4.
You
can find an example catalog file for GBT observations at http://www.gb.nrao.edu/~dpisano/example.cat.
This file only contains one source.
Pick your favorite galaxy and add it to this catalog file. 5.
You
can find an example scheduling block file for GBT observations at http://www.gb.nrao.edu/~dpisano/example_sb.turtle.
The basic outline of a scheduling block is in this file, but there are
important details that are missing.
Do your best to complete these details using your configuration file and
catalog file as needed. Please have your configuration,
catalog, and scheduling block files completed and accessible when you arrive in
Green Bank. Everyone will get a
chance to use these during our drift scan observations on Wednesday night
(although you will be stuck observing the position that is drifting through the
GBT beam wherever it is pointing).