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Frequency Coverage and RFI Observations at Effelsberg. K. Grypstra, R. Keller, Max-Planck-Institut für Radioastronomie, Bonn, Germany. Overview. Frequency coverage and protected bands RFI at low frequencies Observations in an RFI polluted environment. Frequency coverage. Frequency coverage. - PowerPoint PPT Presentation
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Frequency Coverage and RFI Observations at Effelsberg
K. Grypstra, R. Keller, Max-Planck-Institut für Radioastronomie, Bonn, Germany
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
2
Overview
• Frequency coverage and protected bands
• RFI at low frequencies• Observations in an RFI polluted
environment
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
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Frequency coverage
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Protected Bands
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
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Frequency coverage
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Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
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Frequency coverage
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E-VLA RX
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
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RFI at 18cm
• RFI Signal
• Spectral Lines(same scale)
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
7
RFI examples: TV
• Analogue– High level
carriers– Low spectral
density in between
• Digital– No carriers– High
spectral density
– Lower power level
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
8
RFI by Radar Signals
• Radar Spectrum at Effelsberg
• 1.0 – 1.2 GHz • Setup:
Log Periodic+ 120K LNA+ Spectrum Analyzer
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
9
RFI at 21cm
Setup:• 100m RT• 15K RX• 9x20MHz
Source:• PCs?• Media
Converters?• WebCam?• Radar?• ?
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
10
RFI at 18cm
Setup:• 100m RT• 20K RX
Source:• PCs?• Media
Converters?• WebCam?
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
11
RFI at 18cm
BackendArtefacts
Setup:• 100m RT• 20K RX• FFT-Spectr.
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
12
Airplane Radar Altimeter
• Airplanes over Effelsberg
• 4.2-4.4GHz• 2hrs• Aaronia
Spectrum Analyzer(2k€)
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
13
RFI examples: UMTS
• UMTS• On the field• Setup:
– LogPer– 200K LNA– R&S FSH6
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
14
RFI examples: Wireless
• WLAN 2.4GHz• Spectrum
50MHz
• Setup:– LogPer– 200K LNA– R&S FSH6
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
15
RFI examples: Wireless
• WLAN 5.28GHz
SAPOS-GSM
WLAN
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
16
RFI examples: Wireless
• WLAN 5.28GHz• Time Series• OFDMA
Orthogonal Frequency Division Multiple Access
• Setup:– LogPer– 200K LNA– R&S FSH6
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
17
RFI: Electric Fences
• Distances0,5-1km
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
18
RFI: Electric Fences
• ‚Pulsar‘1.382sec
• Setup:– 100m RT– 20K L-Band RX– FFT Anal.
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
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Ultra Wide Band
• UWB Generator
• @ 0-5GHz• Spurious up to
18GHz
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
20
RFI and Measurements
• GSM900• Setup:
– LogPer.– 120K LNA– 30dB
Gain– R&S FSH6
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
21
RFI and Measurements
• GSM900• Setup:
– LogPer.– 200K LNA– 12dB
Gain– R&S FSH6
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
22
RFI and Measurements
• GSM900• Setup:
– LogPer.– 200K LNA– 12dB
Gain– R&S FSH6– Pointed
to zenith
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
23
Observations through RFI
• 3C28618.6Jy
• @21cm
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
24
Usable Frequencies
• 50cm: 608-614MHz protected; TV band IV narrow BW
• 21cm: 1.4-1.427GHz protected, outside critical
• 13cm (S): 2.2-2.29GHz prot. (no observation / experience)
• 11cm: 2.69-2.7GHz protected, surrounded by radar
• 9cm: 3.26-3.267GHz & 3.332-3.339GHz narrow BW
– 4-4.2GHz Airplane Radar Altimeter
• 6cm: 4.8-5GHz prot.; free in wide bands
– 5.1-5.5GHz earth bound radar, WLAN
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
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Usable Frequencies
• 5cm: 5.7-6.7GHz nothing prot.; free in wide bands
• 3.6cm (X): 8.215-8.4GHz prot.; >9GHz classical radar
• 2.8cm: 10.6-10.7GHz; not usable in practice → TV-sat
• 1.9cm: 14.47-14.5 & 15.35-15.4GHz prot.; radar @ 16.7
• 1.3cm: 22.01-24GHz prot. with gaps; ptp comm. @ 24
• Above: more or less free (cloudsat @ 86)
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
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Usable Frequencies
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Don't use!
Wettzell;March 18-20, 2009
Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR
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Don‘t suppress!
Setup:
• 100m RT, 15K RX, 20MHz BW, 1420MHz CF.
Recommended