CANADIAN METEOR ORBIT RADAR (CMOR)
==================================

  Instrument Overview                                                         
  ===================                                                         
    The Canadian Meteor Orbit Radar (CMOR) is located at the University of    
    Western Ontario (UWO) meteor radar complex near Tavistock, Ontario, and   
    has been in operation since late 2001.  It consists of three separate     
    interferometric radars, synchronized in transmission and reflection and   
    operating from a single site.  Details of the system may be found in Jones
    et al. (2005) and Webster et al.  (2004).                                 
                                                                              
    The three systems operate at 17.45, 29.85, and 38.15 MHz.  The 'orbit'    
    component of the system applies only to the 29.85 MHz system which has two
    outlying remote stations (6.2 and 8.1 km respectively from the main site) 
    providing reflections from portions of the meteor trail not directly      
    accessible from the specular reflections to the main site.  For these     
    echoes, the interferometry from the main site provides sufficient         
    information to permit measurement of velocity vectors for individual      
    meteors.                                                                  
                                                                              
    Each of the three systems has seven antennae and seven separate receivers.
    For the 17 and 38 MHz systems all seven receivers are used for reception  
    (to boost signal to noise levels) but only five are used for determination
    of the measured echo direction using interferometry.  The 29 MHz system   
    uses the two extra receivers to record signals from the two outlying      
    stations.                                                                 
                                                                              
    The transmit and receive antennae have broad (nearly all-sky) gain        
    patterns.  The transmit antenna is a vertically directed                  
    horizontally-polarized three-element Yagi with G = 7.6 dB(i) (relative to 
    an isotropic radiator) and a beam width to the 3 dB points of 30 degrees. 
    The receive antennae are all two-element vertically directed horizontally 
    polarized Yagis with G = 6.5 dB(i) and beam widths of 45 degrees to the 3 
    dB points.  Directions to each echo are measured using the relative phase 
    difference between the antennae within each of the 5-element              
    interferometer arrays.  The interferometric error is less than 0.5 degrees
    for echoes with elevations above 30 degrees found for simulation for      
    echoes with SNRs of 15 dB.  Due to the degradation in interferometric     
    accuracy at low elevations, no echoes are processed with their nominal    
    elevation is below 20 degrees.                                            
                                                                              
    All receivers are cosmic noise limited.  The variation in noise levels is 
    controlled principally by galactic cosmic noise at HF/VHF frequencies and 
    produces a diurnal noise variation of 2 dB for the 29 and 38 MHz systems. 
    The 17 MHz system suffers from heavy terrestrial interference during the  
    day, limiting useful echo detections to night-time hours only.  For the 29
    MHz orbital system, the absolute minimal detectable signal strength       
    corresponds to meteors with radio magnitudes near +9.  However, effective 
    counting statistics for 29.85 MHz are complete only to +8 due to the      
    roll-off in sensitivity as the absolute detection threshold is reached -  
    this is the effective detection limit for the radar and corresponds to    
    meteoroids of ~10^-7 kg mass for an average velocity of 30 km/sec.        
                                                                              
    References:                                                               
                                                                              
    Jones, J., P. Brown, K.J. Ellis, A.R. Webster, M. Campbell-Brown, Z.      
    Krzemenski, and R.J. Weryk, The Canadian Meteor Orbit Radar: system       
    overview and preliminary results, Planetary and Space Science 53, 413-421,
    2005.                                                                     
                                                                              
    Webster, A.R., P.G. Brown, J. Jones, K.J. Ellis, and M. Campbell-Brown,   
    Canadian Meteor Orbit Radar (CMOR), Atmos. Chem. Phys. Discuss. 4,        
    1181-1201, 2004.

References
==========

Jones, J., P. Brown, K.J. Ellis, A.R.   
        Webster, M. Campbell-Brown, Z. Krzemenski, and R.J. Weryk, The        
        Canadian Meteor Orbit Radar: system overview and preliminary results, 
        Planetary and Space Science 53, 413-421, 2005.

Webster, A.R., P.G. Brown, J. Jones,    
        K.J. Ellis, and M. Campbell-Brown, Canadian Meteor Orbit Radar (CMOR),
        Atmos. Chem. Phys. Discuss. 4, 1181-1201, 2004.