GBT Remote
Observing Training for UAT
June 19-22, 2018
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 20
15:15-15:45: Lecture on GBT observing
16:30-18:30: GBT Drift Scan observing in teams
Friday, June 22
07:30-11:30: GBT Observations of Pisces-Perseus
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.
http://greenbankobservatory.org/wp-content/uploads/2017/07/GBTpg.pdf
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.
http://greenbankobservatory.org/wp-content/uploads/2017/06/GBTog.pdf
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: http://greenbankobservatory.org/gbt-observers/visitor-facilities-policies/data-reduction-gbt-using-idl/
Otherwise, you can find detailed
descriptions of all the code in the Reference Manual at http://gbtidl.nrao.edu/.
4.
If you want some
demonstrations of how to use Astrid & Cleo, you should check out the short
video tutorials at https://greenbankobservatory.org/gbt-observers/#training.
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).