Rfi measurements at the wsrt
Download
1 / 18

RFI measurements at the WSRT - PowerPoint PPT Presentation


  • 193 Views
  • Uploaded on

RFI measurements at the WSRT. Hans van der Marel ASTRON RFI Mitigation workshop, Groningen, 29-31 March 2010. Introduction. Astronomical observations Local or non-local interference Spectrum monitoring station National Frequency allocation table Test observations for less known bands

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'RFI measurements at the WSRT' - issac


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Rfi measurements at the wsrt

RFI measurements at the WSRT

Hans van der Marel

ASTRON

RFI Mitigation workshop, Groningen, 29-31 March 2010


Introduction
Introduction

  • Astronomical observations

    • Local or non-local interference

  • Spectrum monitoring station

  • National Frequency allocation table

  • Test observations for less known bands

  • Investigations for local interference




Spectrum monitoring station
Spectrum monitoring station

  • Current station operational since 2005

    • Latest antenna modification December 2007

  • Continuous coverage 20 - 3000 MHz

  • Scanning 24/7

  • Calibrated data

  • Data in RMDF format

  • Analysis program available

  • Data available to CRAF


Set up of monitor station
Set-up of Monitor Station

R&S HF902

R&S HK309

Roof of construction hall

Construction hall

coax

Antenna switch

coax

Control cable

coax

converter

R&S EB200 receiver

coax

UTP

Field

Main building

Control computer

Glass fiber

To ASTRON network


Rohde schwarz eb200 miniport receiver
Rohde & Schwarz EB200 Miniport receiver

  • Frequency range 10 kHz - 3 GHz

  • Noise floor -117 dBm @ 30 kHz BW

  • Scan speed 126 points/s 20 - 3000 MHz in 13.5 min @ 30 kHz BW


Rohde schwarz antennae

HK 309

Freq range: 20 - 1300 MHz

Passive

Linear polarization

HF 902

Freq range: 1 - 3 GHz

Passive

Linear Polarization (V used)

Rohde & Schwarz antennae


Schematic of control program
Schematic of Control Program

Measurement module

Measurement

file

measure.dat

Calibration

files

*.dat

TCP/IP connection

EB 200 measurement receiver









Investigations of local or internal interference
Investigations of local or internal interference

  • Usually in 1 or few telescopes

  • Malfunctioning equipment

    • E.g. oscillating amplifiers, leaking of LO

  • Interfering equipment

    • Computers, networks, lab equipment

      Tools:

  • Handheld antennas, probes, spectrum analyzer, receiver

  • Experience


Summary
Summary

  • Astronomical observations are inspected,they are the most sensitive

    • Autoplots give first indication

    • Reports from astronomers

  • Spectrum monitoring station gives indication about possible RFI

  • Test observations can reveal real usability of frequency band

  • Good relation with National Agency is important

  • Know your enemy (e.g. Galileo)

  • Local and internal interference requires continuous attention


ad