TOW 2013: Course Descriptions

There are four types of courses to be offered at the Technical Operations Workshop (TOW). All courses 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.

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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
Grade level: beginners and advanced levels; some new material.
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 5A and Mark 5B 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 5 Advanced Topics
Teacher: Dan Smythe
Grade level: Advanced; some new material.
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 Experiment Pre-checks and Operations Workshop. 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, 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: 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

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 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: Generating ANTAB Tsys Files (ANTABFS)
Teacher: Uwe Bach
Grade level: Beginners; some new material.
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
Teachers: Brian Corey and Mamoru Sekido
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 will be reviewed, and initial results from broadband surveys undertaken for the VLBI2010 project at several sites will be summarized. A more detailed look at the practical issues and results of such a survey will be presented for the case of the broadband surveys conducted by NICT at several locations in Japan.

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: Hardware Maintenance
Teacher: Rich Strand and Mike Poirier
Grade level: Beginners.
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: Hydrogen Maser Monitoring and Maintenance
Teacher: Irv Diegel
Grade level: Beginners.
Description: The intent of this workshop 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: 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 and Ed Himwich
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 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 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. The VLBI signal path will be traced through a receiver/backend block diagram. It will touch on what can be monitored with the Field System and point out parallels and differences between analog (BBC/VC) and digital (DBBC/RDBE) techniques.

Title: Practical Correlation
Teachers: Alessandra Bertarini and Mike Titus
Grade level: Beginners; new material.
Description: Hands-on activities on the DiFX: brief introduction on what a correlator is, preparation of files for correlation, correlation and search for fringes with interpretation of the fourfit output. Various exercises to detect common problems at stations that would need to be resolved. This workshop will also deepen the understanding of the correlator reports. The aim of the exercises is to promote the mutual understanding between stations and correlators. Students are encouraged to put questions related to their stations to the representatives from the correlators, who will be available for personal discussions throughout the duration of the TOW.

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

Title: Pointing and Single Dish Amplitude Calibration Theory
Prospective teachers: Uwe Bach
Grade level: Beginners.
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: Next Generation GPS Timing for the Mark 5 Era
Teachers: Tom Clark and Richard Hambly
Grade level: Beginners; some new material.
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: 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: Writing VLBI Observation Schedules
Teacher: John Gipson
Grade level: Beginner; new material.
Description: This seminar will describe how a VLBI observation schedule is created based on the software package 'sked'.

Title: DBBC Setup and Operations
Teacher: Gino Tuccari
Grade level: All levels; some new material.
Description: This seminar will give an introduction into the installation and operations of the digital backend DBBC, pointing out the present legacy and VLBI2010 observation capability. An overview of the latest development of DBBC3 will show the upgrade and novelty of this VLBI platform.

Title: RDBE Setup and Operations
Teachers: Chet Ruszczyk
Grade level: Beginners; new material.
Description: This seminar will give an introduction into the installation and operation of the digital backend RDBE.

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
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 and Jim Lovell
Grade level: Beginners; 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: Cable-wrap: what it is and how to deal with it
Teacher: Ed Himwich
Grade level: Beginners; new material.
Description: The basics of cable-wrap will be described. In addition, how to deal with it during scheduled observing will be covered as well as how SKED handles cable-wrap in schedules. More advanced material on how to implement it in the local antenna interface, antcn, will be covered from an operational, but not a programming, point-of-view.

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

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: 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: John Gipson
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.

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; 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, called VLBI2010, will be described. 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 VLBI2010 projects anticipated to result in a global VLBI2010 network in the foreseeable future.

Title: Mark 6 System Description
Teacher: Alan Whitney
Grade level: Beginners; new material.
Description: A next-generation VLBI data system based completely on commercial off-the-shelf hardware (COTS) is being developed at MIT Haystack Observatory. Several demonstrations at sustained 8-Gbps recording have been successfully completed. The Mark 6 system will be described in detail.

Title: Using Low-Cost COTS Software Defined Radios (SDR) for Phase Cal and RFI Monitoring
Teacher: Tom Clark and Richard Hambly
Grade level: Beginners; new material.
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.

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Further information: IVS Coordinating Center

Last updated: April 4, 2013