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:


    Read the GBT Proposer's Guide, particularly Section 5.


    Familiarize yourself with GBT Observer's Guide, particularly Section 6.2.4, 6.3, and 6.7.     


    Take a look at the Observer Training Videos, particularly those on Astrid Scheduling Blocks.


    Use these resources to complete the attached Scavenger Hunt. 




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 Reference Manual at


4.     If you want some demonstrations of how to use Astrid & Cleo, you should check out the short video tutorials at 


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:






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  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  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  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).