TOW 2015: Course Descriptions
There are four types of courses to be offered at the Technical
Operations Workshop (TOW). All workshop and seminar classes have a
time slot of 75 minutes; then a 15-minute overlay time follows to
be used for final questions and change of class rooms for the
subsequent class. Lectures have a time slot of 30 minutes, except
for the VLBI Basics lecture which is 60 minutes long.
- Operations Workshops
are hands-on sessions with a maximum of about 5 participants
each. Each member of the class will have an opportunity
to participate actively in the training.
- Maintenance Workshops
are presentations to an audience of 10-20 people.
The classes will begin with instruction and demonstration, and
there may be some hands-on training. A large fraction of the time
is allowed for discussion and question/answer periods.
The subject matter includes a variety of topics.
- Seminars
are presentations including demonstrations
to an audience of 20-60 people, depending
on the topic. The subject matter includes a variety of
special interest topics.
- Lectures
are intended for a general audience. The
subject matter includes topics that we believe are of interest to
everyone, or include announcements or information that everyone
should be aware of. All attendees at the workshop will be
scheduled for the lectures.
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Operations Workshops are hands-on sessions with a maximum
of about 5-7 participants each.
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Title: VLBI Session Pre-checks and IVS Operations
Teachers: Rich Strand and Mike Poirier
Grade level: beginners and advanced levels; new material on the
VGOS operation will be included.
Description:
This is a double-length class that will include both pre-checks and operations.
This class is offered with two formats. One format is for students with stronger
English skills and will move at a faster pace. The other format is for students
with weaker English skills, will move at slower pace, and have more pauses for
material that may be difficult to understand in translation.
Pre-checks: We will practice all of the procedures and operational tests
that should be performed before each experiment to insure that all of the equipment
is set up and working properly, starting with drudging the schedule file and ending
with pre-session e-mail to ops.
Pointing and gain calibration
will be covered in separate workshops.
This class is for people who use the PC Field System to control data racks such as
the Mark IV, VLBA, DBBC and RDBE. The Mark5B and Mark6 will be discussed at the
operational level. The class will use the Westford VGOS system and the Mark IV,
with appropriate notes made about differences for other systems. The RDBE and
Updown converters will be discussed in detail.
Operations: We will practice experiment operations from starting the
schedule to the post-session operational report with hands-on by students during
the session. The use of the "logpl" program for plotting data from the log during
and after the experiment will be demonstrated along with other tools available
found in the PCFS. This class will be held at Westford, using the VGOS RDBE and
Mark 6 recorder.
Title: Mark 5 Advanced Topics
Teacher: Dan Smythe
Grade level: Advanced.
Description:
What operators don't need to know about Mark 5, but should.
This workshop will focus on Mark 5B(+) and will cover advanced topics not
covered in the VLBI Session Pre-checks and IVS Operations.
Trouble-shooting tools and techniques will be demonstrated. Theory of operation
will be discussed to provide a deeper understanding of what is happening inside
a Mark 5 recorder, and how it affects operations. Topics to be covered include Mark 5
stand-alone testing, StreamStor and Mark 5 utility programs, software correlator
for station checks, voltage and temperature monitoring, and remote chassis power
control.
Title: Operational Use of Mark 6 for Early Adopters
Teacher: Chet Ruszczyk
Grade level: Advanced for early users.
Description:
This class will provide further details and explanations of operating
Mark 6 systems at stations extending on what is covered in the VLBI
Session Pre-checks and IVS Operations class. In addition details will
be given on the usage of Mark 6 systems when attached to a correlator. There are
commonalities between the two deployment options; however, there are also
operational pecularities for each option that early adopters should be aware
of.
Title: Cryogenic System and Receiver Maintenance
Teacher: Jay Redmond
Grade level: Beginners.
Description:
This workshop will address cryogenic system and receiver maintenance from the
operational perspective. The goal is to improve system reliability, reduce
downtime, and lower operational cost. Workshop participants will receive
helpful hints for recovery from vacuum failures, contaminated helium systems,
and the use of standardized maintenance procedures with some common pitfalls
identified. General cryogenic "Do's and Don'ts" will be discussed. This
session will not address the theory of cryogenics or the internal workings
of a dewar.
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Maintenance workshops are presentations or demonstrations
to an audience of 10 or fewer people, with discussion and questions.
There may be some hands-on training.
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Title: Mark 5 Disk Module Testing and Shipment
Teacher: Don Sousa
Grade level: Beginners.
Description:
The first part of this workshop will lead participants through the testing
and conditioning of Mark 5 disk modules. Topics will include the erasing and
conditioning of a module, guidelines for mechanical inspection, and repair of
detected mechanical damage. The second part will deal with preparing the
modules for shipment, including labelling techniques and customs procedures.
Title: Automated Pointing Models Using the FS
Teacher: Ed Himwich
Grade level: Beginners and advanced levels.
Description:
This class will be offered at two levels. One level will concentrate on basics
for students who do not have much experience with the tools presented and want
an introduction. The other level will be for students with more experience or
want to address more advanced topics. The course will cover basic support for
pointing measurements in the Field System. It will also include a demonstration
of the "pdplt" program for analyzing pointing data. It will describe basic
principles for configuring the mdlpo.ctl and ctlpo.ctl files
that control the automated pointing data acquisition and delogging processes.
Gain calibration will be covered in separate workshops.
Title: Antenna Gain Calibration
Teacher: Michael Lindqvist
Grade level: Beginners; some new material.
Description:
This course covers using ONOFF and GNPLT. Instruction will be given on the
preparation and execution of ONOFF for the automatic acquisition of amplitude
calibration data. Attendees will learn about the necessary procedure files,
methods of measuring noise diode temperature and gain curves, and the
interpretation of the resulting log files. The course will provide basic
instruction on analyzing gain calibration data with GNPLT. Typical tasks
(such as calibration of Tcal and gain curves) will be described step-by-step,
a general discussion about GNPLT data analysis capabilities will also be held.
Some time will be reserved to include the possibility of giving feedback and
requesting improvements in the features of the gain calibration tools.
Title: RFI Sources, Identification, Mitigation
Teachers: Brian Corey and Hayo Hase
Grade level: Beginners; some new material.
Description:
This workshop will cover the effects of radio interference on VLBI
observations, sources and identification of RFI, and possible mitigation
techniques for RFI. Methods for conducting an RFI survey and calculating
the impact of an RFI source on VLBI observations will be reviewed.
Title: Phase Cal Basics and RF System Testing
Teacher: Brian Corey
Grade level: Beginners.
Description:
The phase calibration system is the primary means for ensuring that
instrumental effects in the receiver and VLBI terminal do not corrupt
the group delay measurements. This course will cover the basic concepts
and hardware implementation of the calibration system, including the
Mark IV cable measurement system. The nature and causes of spurious
signals, which can degrade the calibration accuracy, will be described.
Following the phase cal basics we will review the fundamentals of measuring
a power spectrum with an analog RF or FFT-based spectrum analyzer.
Applications to VLBI system testing and trouble-shooting will be
discussed and demonstrated, with a particular emphasis on phase noise
and modulation in LO and phase calibration systems. The detection of
spurious phase cal signals with a spectrum analyzer will also be treated,
along with the diagnosis and cure of such signals.
Title: Operational Recovery from System Failures
Teacher: Rich Strand and Mike Poirier
Grade level: Advanced level with frequent student interaction.
Description:
Loss of data issues compiled from 2014 from all stations will be discussed
in detail with proper recovery and simulations. This will be open forum with
input and suggestions from all advanced students, many that have experienced
these issues. Topics will include: (1) Power failure recovery, starting from
scratch. (2) Telescope failure, stuck, poor offsets, slewing. (3) Mark 5 and 6
issues including operational recovery guidelines and power supply repair.
(4) Maser signal failures including 5 MHz and 1PPS at the operational level
to recover. (5) Data rack failure from Video Converters, Receiver and IF
issues, Phase calibration, RDBE and Up-Down converters. Station repair
guidelines and proper tools and test equipment for students that may have
these skills.
Title: Mark 5 and RDBE OS Software Development
Teacher: Chet Ruszczyk
Grade level: Beginners.
Description:
The Mark 5 VLBI and eVLBI community needs a stable and up-to-date OS
to help continue the development of technologies and maintain a secure
environment. After considerable investigation, we have selected a
Debian-based distribution as the new OS and will explain the deployment
and upgrade for current Mark 5 systems out in the community. Moving the
Mark 5 to a Debian-based OS will make the Mark 5 more similar to FS,
which is also Debian based. The reasons for moving to the new OS will
be explained, as well as the details of making the changeover and the
differences that will be encountered.
Title: Advanced Pre-checks and Operations
Teachers: Brian Corey
Grade level: Beginners.
Description:
This course is intended to provide a description of the tests that stations should
periodically perform to evaluate the performance of their station. These checks are more
advanced than the ones covered in the VLBI Session Pre-checks and IVS
Operations course, but most are covered in more detail in other courses. This course
works through the list of checks, explains the reasons for the tests, provides some tips
on performing them, how to use systests scripts for automating and analyzing
measurements, and a chance to ask questions about them. The systests scripts
are an important tool for testing and verification for stations that have Mark IV Decoders.
In order to have a full grounding in this material it is recommended that anyone signing
up for this course should also take some other courses unless they are already familiar
with the material in these courses. The recommend other courses are: RFI
Sources, Identification, Mitigation and Phase Cal Basics and RF System
Testing. Some additional material on troubleshooting not covered in other courses
will be presented here. This course will also give an introduction on how VLBI electronics
works.
Title: Understanding Correlator Feedback
Teachers: Alessandra Bertarini, David Hall and Daniel Veillette
Grade level: Beginners; new material.
Description:
This seminar covers the coordination of observations, the logistics of media
distribution, the set up of correlation, the analysis of results and the feedback
to stations. Particular emphasis will be on correlator-station communication
from the station reports and logs to correlator feedback. Representatives from
the correlators will be available for discussions and advice on issues regarding
your station.
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Seminars are presentations including demonstrations
to an audience of 10 or more people, depending on the topic.
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Title: Differences between Mark 5 and Mark 6
Teacher: Alan Whitney
Grade level: Beginners.
Description:
The currently widely used Mark 5 (in its various flavors) VLBI data system
is based on a significant amount of proprietary technology yielding record
rates of up to 2048 Mbps (Mark 5B+) or 4096 Mbps (Mark 5C). For the VGOS
network, the next-generation VLBI data system Mark 6, which is based
completely on commercial off-the-shelf hardware (COTS) and open-source
software, will be employed allowing recording and playback rates of up to
16 Gbps. This class will describe the differences as well as the commonalities
of the two data systems as they are applied in the field.
Title: Pointing and Amplitude Calibration in Theory and Practice
Teacher: Uwe Bach
Grade level: Beginners; some new material.
Description:
In this course students will learn why accurate pointing corrections must
be known for all parts of the sky to be observed, and how pointing errors
affect geodetic and astronomical results. Students will learn how SEFD and
system temperature measurements are related, how to check the focus, how
to make SEFD measurements, how to measure a gain curve, which sources are
best for the SEFD measurements, how weather can affect the measurements and
results, and how the SEFD measurements are used for data analysis and scheduling.
We will discuss measurement equipment and how it may affect the results if
care is not taken. We will also describe the use of the ANTABFS suite of
scripts for producing well-calibrated and formatted system temperature and
gain curve tables, suitable for use in the common data analysis packages.
It will include some explanation of how the information is obtained and
why good quality amplitude calibration is important; and some examples
of typical errors will be presented.
Title: High-accuracy Time and Frequency in VLBI
Teachers: Katherine Pazamickas, Tom Clark and Richard Hambly
Grade level: Beginners; some new material.
Description:
This presentation will provide an overview of the use of high-accuracy time
and frequency in VLBI. This will include a discussion of all the "clocks"
used in VLBI (Hydrogen Masers, GPS timing clocks, the clocks inside the
Field System computer and the clock information needed by the correlators)
and how they need to be tied together in order to guarantee successful
VLBI measurements. Some focus will be put on the different types of
masers with block diagrams as well as generalized operational procedures.
Title: Topics in FS Station Software Coding
Teacher: Ed Himwich
Grade level: Advanced.
Description:
This session will be organized as a group discussion/demonstration. It
will provide an opportunity for people to present questions they have
about implementing specific station features and to get advice on how to
do it. There is no separate lecture this year covering more of the
basics of station software coding, but the notes from previous years
will be included and that topics can addressed at some level depending
on people's interests and the time available.
Title: DBBC Setup and Operations
Teacher: Uwe Bach
Grade level: All levels; new material.
Description:
This seminar will give an introduction into the installation and operations
of the digital backend DBBC. In its digital down conversion mode the DBBC2
is fully integrated into the Field System and a number of EVN stations use
the DBBC2 for regular VLBI observations. It will be shown how to install,
test and operate a DBBC to replace an existing analog backend. The DBBC2
is capable of processing 8 RF/IF inputs from different bands and/or
polarization between 10 MHz and 3072 MHz (with ADB2) to produce a group
of up to 64 output data channels using two VSI output connectors at a
maximum data rate of 2 Gbps each. It is fully compatible to the existing
analog VLBI backends, but at the same time provides the flexibility to
observe at higher bandwidth and recording rates to meet the future VGOS
observation capability.
Title: e-VLBI Overview
Teacher: Chet Ruszczyk
Grade level: Beginners; some new material.
Description:
The transmission of VLBI data via high-speed networks, dubbed 'e-VLBI',
is developing rapidly. This seminar will explain the basics of e-VLBI.
Topics covered will include general topics such as the advantages of
e-VLBI and types of networks. But also more detailed questions such as
how to extract data files from the Mark 5 system for e-VLBI operations
will be discussed.
Title: e-transfer Operations
Teacher: Jason SooHoo and David Hall
Grade level: Beginners; new material.
Description:
This course will cover operational aspects of performing e-transfers of
data between stations and correlators.
Title: FS Remote Operations
Teacher: Alexander Neidhardt
Grade level: Beginners; some new material.
Description:
We will show the FS remote interface (e-RemoteControl) for users to see
and offer feedback on. The related Ethernet communication infracstructure
for the FS will also be briefly described.
Title: jive5ab and FlexBuff: VLBI data recording and transport utilities for the 21st century
Teacher: Harro Verkouter
Grade level: Beginners; new material.
Description:
In this course I will introduce, explain and, equipment willing, demonstrate
a couple of (e-)VLBI capable tools developed in the EVN. A separately
developed Mark5 control program, jive5ab, supports a wide range of (e-)VLBI
recording and transport capabilities, both real-time and non-real-time. It
allows for freely moving VLBI data between various types of recorders and
file servers. Of particular interest could be the built-in support for a
high-performance network protocol, UDT, which typically performs an order
of magnitude better than TCP on high-bandwidth, high-latency international
network links. The course will also briefly introduce the EVN developed
FlexBuff (Ethernet) VLBI recorder which plays a crucial role in the planned
disk-shipping less operation of the EVN.
Title: MCI Monitoring and Control
Teacher: Alexander Neidhardt
Grade level: Beginners; new material.
Description:
We introduce the MCI Monitoring and Control system at Wettzell with its
own hard- and software.
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Lectures are intended for a general audience.
All attendees at the workshop are welcome to attend the lectures.
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Title: VLBI Basics
Teacher: Alan Whitney
Grade level: Beginners.
Description:
This lecture will describe the VLBI technique from scheduling to data
capture, to correlation and to analysis. It will cover the basic concept,
observational system, delay resolution function, correlation, and observables.
Title: VGOS-related Developments in Japan
Teacher: Mamoru Sekido
Grade level: Beginners; new material.
Description:
This lecture will give an overview of the VGOS-related development
activities in Japan and provide information on data acquisition systems.
Two broadband observation projects are ongoing in Japan: one is the new
VGOS observation station at Ishioka undertaken by GSI and the other is
the GALA-V project of NICT. GSI is not only preparing the VGOS antenna
but also the new data acquisition system K6/iDAS, which is being designed
to be compatible with VGOS specifications. The system has been tested and
will become available in the near future. NICT is working on a new broadband
VLBI system, called GALA-V, intended for distant frequency transfer. Not
constructing a new antenna, NICT has upgraded its Cassegrain-type 34-m
antenna to a VGOS-compatible broadband observation system including the
original development of a broadband feed. Additionally, a new direct sampling
data acquisition method with the new high-speed sampler K6/OCTAD-G (GALAS)
has been developed. Also a VGOS semi-compatible observation mode is possible
by using the analog down converters together with the DBBC sampler ADS3000+.
This lecture will provide an overview of the systems of GSI and NICT. We
anticipate that this information will be useful for future joint VLBI
observations.
Title: Impact of Operations on Data Analysis
Teacher: Ed Himwich
Grade level: Beginners.
Description:
This course will describe the effect on geodetic data analysis of
various problems during data acquisition. Problems such as clock
breaks, bad tracks, parity errors, pointing errors, warm receivers,
and late starts will be covered.
Title: Science Overview
Teacher: David Gordon
Grade level: Beginners; some new material.
Description:
An overview of the scientific goals of geodetic and astrometric
programs will be presented. Particular emphasis will be placed
on reference frames which are the fundamental products of VLBI.
Specific topics will include re-observing the VLBA Calibrator
Surveys for ICRF3, ITRF2014, and near-field correlation.
Title: Field System Near Term Future Plans
Teacher: Ed Himwich
Grade level: Beginners and advanced levels.
Description:
This presentation will cover the immediate and long-term plans for
Field System development. The ongoing collaboration and cooperation on
the Field System among various groups will be described.
Title: Broadband and the Evolution of the VGOS Network
Teacher: Arthur Niell
Grade level: Beginners; some new material.
Description:
After a short review of the history of geodetic VLBI and a summary
of recent results, the presentation will deal with future perspectives.
The goals and requirements of the next generation VLBI system will be
described (VGOS: VLBI Global Observing System). Based on extensive simulation
studies, strategies have been developed to significantly improve product
accuracy through the use of a network of small (12-m) fast-slewing
antennas. A new method for generating high precision delay measurements
and improved methods for handling biases related to system electronics,
deformations of the antenna structures, and radio source structures
have been developed. The presentation will conclude with an overview
of the various VGOS projects anticipated to result in a global
VGOS network in the foreseeable future.
Title: Using Low-Cost COTS Software Defined Radios (SDR) for Phase Cal and RFI Monitoring
Teacher: Tom Clark and Richard Hambly
Grade level: Beginners.
Description:
This lecture will describe the commercial off-the-shelf (COTS) Software Defined
Radios (SDR) and their application in determining phase cal and monitoring RFI.
Title: DBBC Developments
Teacher: Gino Tuccari
Grade level: Beginners; new material.
Description:
This lecture will describe current developments and upcoming plans for the next
generation of digital backends of the DBBC family.
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Further information:
IVS Coordinating Center
ivscc@ivscc.gsfc.nasa.gov
Last updated: March 27, 2015