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Report on the new VGOS 12m radio telecope at Kokee Park Geophysical Observatory

Chris Beaudoin, Alan Whitney, Arthur Niell, Brian Corey, Chet Ruszczyk, Chris Eckert, Mark Derome, Russ McWhirter, Jason SooHoo, Mike Titus, Alan Rogers, Peter Bolis, Roger Cappallo, Jon Byford - MIT Haystack Observatory Chopo Ma, Larry Hilliard, Tom Clark – NASA GSFC Ed Himwich – GSFC/NVI Bill Petrachenko – Natural Resources Canada Javier Gonzalez Garcia – Yebes Astronomical Observatory

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Overview

Frontend – Block Diagram – RF Design – Antenna/Mechanical Design

Backend – Block Diagram – Equipment Rack Layout – VGOS UDC w/ baseband output – RDBE-G v3.0

Signal Chain Calibration Subsystem Monitor/Control VLBI Data AcQuisition (VDAQ) Module Schedule

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Frontend – Block Diagram

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Frontend – RF Design

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Frontend – Antenna

• Main reflector surface comprises 100 precision

adjustable stretch formed aluminum panels,

• Carbon fiber composite sub-reflector with optional

high accuracy hexapod adjustment mechanism

• Precision zero backlash torque biased mechanisms

based on COTS motors and controllers

• Extensively galvanized and painted to assist with

corrosion protection, galvanic protection built in by

design

• Meets all the VLBI2010 specifications

• Suitable for array applications

• Passed CDR in July 2014

High accuracy, high slew speed, full motion 12m Antenna System

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Frontend – Mechanical Design

Fiber Tx High/Low Band

Electronics

Turbo Pump

E/mech Vac Valve

Vac Gauge

Cal Generator

Mon/Con VDAQ Module

Payload Interface LNA Bias Supplies

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Backend – Block Diagram

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Backend – Equipment Rack Layout

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Backend – VGOS UDC

• Supports 2-14 GHz input RF Frequency • Provides 2 GHz baseband output • Net LO tuning resolution < 1 Hz

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Backend - RDBE-G v3.0 Firmware

Pulse Calibration Extraction

Raw Capture Histogram

Raw Capture Spectrum

Raw Capture Samples

Noise Diode Off Accumulators Noise Diode On Accumulators •Sy

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Signal Chain Calibration Subsystem

FE Antenna Unit

BE Ground Unit

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Signal Chain Calibration – Antenna Unit

Ethernet/PoE Interface Main Supply and drive signals

Dual Phase/Noise Calibration Signal Outputs

5 MHz Reference

Input

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Signal Chain Calibration – CD Stability

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VLBI Data Acquisition Module

VLBI Data AcQuisition (VDAQ) module – Open-source hardware development – Hot-Swappable – Deployable Temperature, Pressure, Humidity Sensing – On-board temperature sensor – Logging to SD card

Interface – Ethernet Communications – Powered over Ethernet

• Isolated DC Power Sources

– 16 Analog Monitors • Single-ended or Differential • Isolated or Non-Isolated • Configurable signal conditioning

– 40 Digital Monitors or Controls • 10 Isolated Monitors • 10 Isolated Controls • 20 Non-isolated Monitors and/or Controls

– RS232 and I2C Communications

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VLBI Data Acquisition Module

Dimensions: 13 x 10 x 2.5 cm

Ethernet/PoE Interface

Monitor/Control Signal Interface

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Schedule

March 2015: Calibration Subsystem Fab Complete

April 2015: Frontend/Backend Subsystems Fab Complete

May 2015: MCI and Integration Complete

May-July 2015: Integrated Testing at Haystack

August 2015: Ship to KPGO

August-Sept 2015: Installation/Testing

Early October 2015: Complete System Test

Oct-Dec 2015: Commissioning

Jan 2016 and beyond: IVS Integration