TOW Course Descriptions

There are four types of courses to be offered at the Technical Operations Workshop (TOW). All courses have a 90-minute time slot.

Back to top

Operations Workshops

Operations Workshops are hands-on sessions with a maximum of about 5-7 participants each.

Title: Experiment Pre-checks and Operations
Teachers: Rich Strand and Mike Poirier
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 Mark IV, VLBA, or VLBA4 racks, and any type of recorder, including Mark 5 recorders. The class will use the Westford Mark IV system, with appropriate notes made about differences for other systems. Operations: We will practice experiment operations from starting the schedule to the post-session operational report and recovery from power failures and other disasters that can occur during a session. The use of the "logpl" program for plotting data from the log during and after the experiment will be demonstrated. This class will be held at Westford, using the Mark IV and Mark 5 recorders.

Title: Mark 5B Operations
Teacher: Dan Smythe
Description: The pre-checks and operation of the Mark 5B system, both in standalone mode and operating with the Field System, will be described. The basic commands required to record, play and check data will be described and demonstrated. Disk-module management at the station will be covered, as well as the normal tests that verify proper Mark 5B operation. A Mark 5B system and a Field System will be available for hands-on use by participants. Mark 5A operations will be covered as part of the Experiment Pre-checks and Operations workshop.

Title: Cryogenic System and Receiver Maintenance
Teacher: Jay Redmond
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.

Back to top

Maintenance Workshops

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.

Title: Mark 5A Disk Module Testing and Shipment
Teacher: Dave Fields and Don Sousa
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
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
Teachers: Alastair Gunn
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: Generating ANTAB Tsys Files (ANTABFS)
Teacher: Cormac Reynolds
Description: ANTABFS is used at astronomy stations to format Tsys data for use in analysis. Currently, this is not used for geodesy, but will be eventually. This course does not need to be attended by students from geodesy only stations. This class will describe 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. There will be a live demonstration of the scripts.

Title: RFI Sources, Identification, Mitigation
Teacher: Brian Corey
Description: This workshop will discuss sources of interference that might affect VLBI observations. Particular emphasis will be placed on the levels and types of RFI that are most harmful to experiments. Also discussed will be techniques to identify RFI and (the limited range of) techniques to deal with it.

Title: Spectrum Analyzer Testing of Analog RF Systems
Teacher: Brian Corey
Description: This course 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: Rack Maintenance
Teacher: Rich Strand and Mike Poirier
Description: This workshop will cover checkout and maintenance aspects of the VLBI electronic racks. Areas to be covered include formatter checkout, VC/BBC performance, and IF distributor checkout.

Title: Mark-5A and Mark-5B Software Updates, Testing, and Maintenance
Teacher: John Ball
Description: Both station and correlator personnel should be familiar with Mark-5A and Mark-5B software testing and maintenance and with acquiring and installing new software versions. This workshop will describe and demonstrate these procedures. Testing and maintenance involve operating the Mark-5A and Mark-5B systems in stand-alone mode, without a Field System or correlator, using a stand-alone program, tstMark5A or tstMark5B. Participants will learn about the Mark-5 native commands, which are different in detail from the corresponding Field System commands, and about interpreting the responses including the DEBUGgery listings. Other stand-alone programs and scripts will also be described and demonstrated. Some of these procedures are useful also for hardware testing. Tutorials will be offered for participants to follow, and Mark-5A and Mark-5B systems will be available for hands-on use.

Title: New OS for Mark 5 System
Teacher: Chet Ruszczyk
Description: The Mark 5 VLBI and e-VLBI 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: General Station Troubleshooting
Teachers: Brian Corey, Dan Smythe, and Ed Himwich
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 Experiments Pre-checks and 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. They will be expanded in the future to support stations that do not have Decoders, but do have Mark 5B recorders. 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, Phase Calibration Basics, and Spectrum Analyzer Testing of Analog RF Systems. Some additional material on troubleshooting not covered in other courses will be presented here.

Back to top


Seminars are presentations including demonstrations to an audience of 10 or more people, depending on the topic.

Title: Correlator Theory
Teacher: Kerry Kingham
Description: This seminar covers the theory behind correlation, with particular emphasis on the Mark IV Correlators. How the correlator works, what it does and what calibrations are applied. The most common problems and their solutions are covered. A description of what the correlator can diagnose for a station and what to look for in the correlator reports. The companion seminar Correlator Operations covers the practical details of correlator procedures.

Title: Correlator Operations
Teacher: Mike Titus
Description: This seminar picks up where its companion seminar Correlator Theory leaves off. It covers the coordination of observations, 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, especially in the context of correlator reports. Representatives from the correlators will be available for discussions and advice on issues regarding your station.

Title: Intro to Linux
Teachers: Jonathan Quick
Description: This course will cover the basics of using Linux (or any UNIX system) for day-to-day housekeeping operations.

Title: Linux System Administration
Teachers: Jonathan Quick
Description: This course will cover system configuration and management issues outside the normal course of experiment operations. The "fsadapt" program which can be used to simplify many of these tasks will be described.

Title: Pointing and Single Dish Amplitude Calibration Theory
Teacher: Alastair Gunn
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 also discuss measurement equipment and how it may affect the results if care is not taken.

Title: Timing Systems
Teachers: Tom Clark
Description: This presentation will discuss all the reasons for needing 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.

Title: Writing Station Specific FS Code
Teacher: Ed Himwich
Description: This course will cover useful information about how to implement station specific code to work with the FS. This includes the programs "antcn" and "stqkr" primarily, but also "cheks", "sterp" and also how to add station-specific help pages. We intend to provide only one level of instruction for this topic. It will combine "beginning", "intermediate", and "advanced" topics, but perhaps lean towards "beginning" and "intermediate". There should be time to deal with some detailed problems at all levels. You should have some experience with FORTRAN and C if you sign up for this section. A separate ad hoc section for discussing implementation of specific features at audience request is also available as "Topics in FS station software coding".`

Title: Topics in FS Station Software Coding
Teacher: Ed Himwich
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. A separate lecture covering more of the basics of station software coding is covered in the "Writing station specific FS code" lecture.

Title: Phase Calibration Basics
Teacher: Brian Corey
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.

Title: Mark IV Decoder
Teacher: Roger Cappallo
Description: The Mark IV decoder is a useful diagnostic instrument in Mark IV and VLBA4 systems. In this workshop the basic architecture, functions, and operation of the decoder will be described, and its capabilities in measuring recorder parity error rates, sample state statistics, and phase cal signal amplitude and phase will be demonstrated. The feature set of the current firmware revision will be discussed, as well as potential future enhancements.

Title: Hydrogen Maser Monitoring and Maintenance
Teacher: Irv Diegel
Description: The intent of this presentation is to provide VLBI personnel with an overview of the hydrogen maser and its use in VLBI. The discussion will be generic so as to accommodate the different types of masers used throughout the VLBI network. Topics will include block diagram analysis of the physics and electronics systems as well as generalized operational procedures.

Title: e-VLBI Overview
Teacher: Chet Ruszczyk
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.

Back to top


Lectures are intended for a general audience. All attendees at the workshop are welcome to attend the lectures.

Title: How VLBI Works
Teacher: Tom Clark
Description: This lecture will describe the VLBI technique from scheduling to data capture, to correlation and to analysis. It will cover the basic concept, observation equations, and some applications.

Title: Mark 5 System Overview
Teacher: Alan Whitney
Description: The Mark 5 system will be described at the block diagram level to give users a basic understanding of the internal workings of the system. The capabilities will be described in some detail, including strategies to deal with bad or failing disks. A short discussion of additional capabilities under development will also be presented. The information presented in this seminar will lay the groundwork for the Mark 5 workshops to follow.

Title: Impact of Operations on Data Analysis
Teacher: Ed Himwich
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: Arthur Niell
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.

Title: IVS Observing Program
Teacher: Dirk Behrend
Description: This lecture will give a short introduction into the IVS and will describe the current Observing Program. Some emphasis will be put on the IVS product delivery goals and their implications for station observing time, correlator, and analysis requirements.

Title: Field System Near Term Future Plans
Teacher: Ed Himwich
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.

Back to top

Return to feedback form

Further information: IVS Coordinating Center

Last updated: April 5, 2007