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RADAR Detection of Extensive Air Showers. Nils Scharf III. Physikalisches Institut A Bad Honnef 31.08.2007. Outline. Cosmic Rays and the Auger Observatory RADAR Principles Test Setup First Results Conclusion. Cosmic Rays. Open questions: Composition Origin Propagation of UHECR

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radar detection of extensive air showers

RADAR Detection of Extensive Air Showers

Nils Scharf

III. Physikalisches Institut A

Bad Honnef 31.08.2007

outline
Outline
  • Cosmic Rays and the Auger Observatory
  • RADAR Principles
  • Test Setup
  • First Results
  • Conclusion

RADAR Detection of EAS

slide3

Cosmic Rays

  • Open questions:
    • Composition
    • Origin
    • Propagation

of UHECR

Measure Extensive Air Showers generated by cosmic rays

RADAR Detection of EAS

the auger observatory
The Auger Observatory

1480 deployed

1400 filled

1364 taking data

082407 ~ 85%

All 4 fluorescence

buildings complete,

each with 6 telescopes

AIM: 1600 tanks

RADAR Detection of EAS

detection methods
Surface detector

Water Cherenkov detector

Samples secondary particles on ground level

Nearly 100 % duty cycle

Fluorescence detector

Measures fluorescence light

Samples shower development

Very sensitive, works only in moonless nights -> 15 % duty cycle

Detection Methods

RADAR Detection of EAS

radar
RADAR
  • Radio Detecting and Ranging
  • Possible sources for reflection / scattering:
    • Metallic objects
      • Airplane monitoring, Car velocity measurements
    • Regions of high ion density
      • Lightning RADAR
      • Atmospheric Probing (Ionized regions in the Atmosphere)
      • Ionization trails of Meteors
        • Used as long range communication channel (commercial and by radio amateurs)
        • Used for meteor science

RADAR Detection of EAS

slide7
Monostatic:
    • Transmitter and receiver close to each other (ideal same antenna)
    • Area around transmitter is monitored

RADAR Detection of EAS

slide8
Bistatic / Forward Scatter
    • Great distance between transmitter and receiver
    • Area between transmitter and receiver is monitored
    • Use of existing transmitters possible

RADAR Detection of EAS

properties of radar for eas
Properties of RADAR for EAS
  • Large monitored volume (several km3)
  • Nearly 100 % duty cycle
  • Active scanning of shower
    • Monitoring longitudinal shower development
    • Detection of horizontal showers
  • Relatively simple detection method
    • Low budget and low maintenance

RADAR Detection of EAS

test setup airplanes
Test Setup - Airplanes
  • Use local transmitter (i.e. TV station)
  • Radio waves reflected on moving airplanes -> Doppler shift
  • Monitor original and Doppler shifted signal

RADAR Detection of EAS

slide11

To antenna

Power Supply for

Preamplifier and Receiver

Sound card

96 kHz

16bit sampling

Preamplifier

Receiver

DAQ

RADAR Detection of EAS

slide12

Demodulation

Receiver frequency 144 MHz

Receiver bandwidth 3 kHz

Radio waves with frequencies from

144.000 MHz to 144.003 MHz

received

amp

Receiver

Bandwidth

freq

144 MHz

amp

Output

Sound waves with

frequencies

from 0 Hz to 3000 Hz

freq

RADAR Detection of EAS

meteor scatter
Meteor scatter

Ionization

Column

Meteor

RADAR Detection of EAS

comparison eas meteors
Meteors

Velocity: ~ 70 km/s

Altitude: 80 km to 120 km

Energy: ~ 0.1 J

Ionization column radius: ~ 10 m

Signal duration: 10 ms – 5 s

EAS

Velocity: nearly c

Altitude: 0 km to 20 km

Energy: 0.1 J (1018 eV)

Ionization column radius: ~ 10 m

Signal duration: 20 µs – 20 ms

Comparison EAS – Meteors

RADAR Detection of EAS

test setup for meteor scatter
Test Setup for Meteor scatter
  • Needed:
    • Transmitter with continuous transmission / high pulse rate below radio horizon of receiver ( distance greater than 500 km)
    • No local transmitter in used frequency range (noise reduction)

RADAR Detection of EAS

slide17

Transmitter site in southern Norway

    • Frequency 144 478 000 Hz
    • Power 120 W
    • Continuous transmission
    • Distance 810 km
    • Matching antenna and receiver for beacon frequency

RADAR Detection of EAS

first results meteor scatter
First Results - Meteor scatter

Receiver Bandwidth

Local transmitter

Expected MS

signals in this

range

RADAR Detection of EAS

first results sound
First Results - Sound

Just 3 examples: different signal types,

sometimes only distinguishable by listening to them

RADAR Detection of EAS

results
Results

Meteor scatter signals with durations between 0.01 s and 3.5 s found

  • Hourly rate between 10 and 20

(higher with active meteor shower)

  • Simple setup working

RADAR Detection of EAS

outlook
Outlook
  • Measurements in coincidence with existing shower detectors
  • Upgrade hardware (higher sampling rate) to detect expected very short EAS signals

Antenna Array

RADAR Detection of EAS

conclusion
Conclusion
  • RADAR is possible new detection method for EAS -> additional information on shower development
  • Detection of meteor scatter with simple setup established
  • Several groups are working on EAS detection by RADAR

RADAR Detection of EAS