The Juliusruh Meteor Radar

Scheme of meteor observations with radars consisting of 1 transmitting antenna (red) and 5 receiving antennas (green).

Short electromagnetic pulses are circumpolarly transmitted and from ionisation traces of invading meteoroids backwards reflected if the ionisation trace is perpendicular corresponding to the radar beam. The meteor echo is received by a reception antenna system consisting of 5 crossed Yagi antennas and is interferometrically analysed, thus estimating the location, the echo amplitude, and the radial velocity of the ionisation trace moving with the neutral wind. From many of such individual observations among other things the wind field for an altitude range between about 80 and 110 km can be estimated. Meteor observations in Juliusruh have continuously been carried out between November 1999 and August 2001 at 32.55 MHz and since May 2007 at 32.55 MHz and 53.5 MHz.

Technical parameters

 

Frequency

32.55 MHz & 53.5 MHz

Peak power

12 kW

Pulse width

13.3 µs

Height resolution

2 km

Transmitting  antenna

1 crossed 3-element Yagi antenna

Receiving antennas

5 crossed 2-element Yagi antennas

 

 

Upper part: Seasonal variation of the temperature near 87-90 km altitude from meteor observations at Juliusruh (54.6°N; red crosses), from OH* measurements at Wuppertal (51.3°N; green points) and from Kalium-Lidar observations at Kühlungsborn (54.1°N; black crosses). Lower part: Temperature deviations of OH* (green points) and Lidar temperatures (black crosses) from Meteorradar temperatures at Juliusruh.

Observation data

  • Individual Meteor echoes (time, location, echo amplitude, radial velocity)
  • Wind field for 80-110 km (hourly mean values, prevailing winds, 12h- and 24h tides)
  • Temperature near 90 km (deduced from diffusion coefficient)
  • Data of invading meteoroids (entry velocity, radiant)