The WAVES instrument is a joint effort of the Paris-Meudon Observatory, the University of Minnesota, and the Goddard Space Flight Center.

Click here for WAVES block diagram

The sensors are

(1) three electric dipolar antenna systems supplied by Fairchild Space (two are coplanar, orthogonal wire dipole antennas in the spin-plane, the other a rigid spin-axis dipole) and

(2) three magnetic search coils mounted orthogonally (designed and built by the University of Iowa).

After preamplification, the sensor outputs are routed to the analysis electronics, consisting of a low frequency (DC - 10 kHz) FFT receiver, a broadband (4 kHz - 256 kHz) multi-channel analyzer designed principally to study the electron thermal noise, two dual radio receivers covering the band 20 kHz to 13.825 MHz, and a time-domain waveform sampler (sampling to 120,000/s).

The experiment is controlled by a central microprocessor (DPU) which will be used in flight to reconfigure the sensor outputs and to maximize the science return for the bit rate and power allotments that are available. A DC/DC power converter is also part of the electronics stack.

The frequency ranges of the five subsystems are shown below:

The principal characteristics of the analysis electronics are summarized in Table 1. In this table the spin-plane electric antennas are referred to as Ex and Ey, the axial electric antenna as Ez and the 3 search coil magnetic axes as Bx, By and Bz.

TABLE 1

 
1.  Low Frequency FFT Receiver (FFT)
 
   Low Band
	Inputs:             	4 of Ex, Ey, Ez, Bx, By or Bz
	Frequency range:    	0.3 Hz - 170 Hz
	No. channels:       	4
	Sensitivity:        	250 microvolts (RMS)
	Dynamic range:      	72 dB 

   Mid Band 
	Inputs:             	4 of Ex, Ey, Ez, Bx, By or Bz
	Frequency range:    	7 Hz - 3.5 kHz
	No. channels:       	4
	Sensitivity:        	10 microvolts (RMS)
	Dynamic range:      	110 dB 

   High Band
	Inputs:             	2 of Ex, Ey or Ez
	Frequency range:    	20 Hz - 10 kHz
	No. channels:       	2
	Sensitivity:        	1 microvolts (RMS)
	Dynamic range:      	128 dB 

2.  Thermal Noise Receiver (TNR)

	Inputs:             	Ex, Ey or Ez
	Frequency range:    	4 kHz - 256 kHz
	No. channels:       	32 or 16 per band (5 bands)
	Bandwidth:          	400 Hz - 6.4 kHz
	Sensitivity:        	7 nV/Sqrt(Hz)

3.  Radio Receiver Band 1 (RAD1)

	Inputs:            	Ex+Ez, Ez
	Frequency range:    	20 kHz - 1,040 kHz
	No. channels:       	256
	Bandwidth:          	3 kHz
	Sensitivity:        	7 nV/Sqrt(Hz)  
 
4.  Radio Receiver Band 2 (RAD2)

	Inputs:             	Ey+Ez, Ez
	Frequency range:   	1.075 MHz - 13.825 MHz
	No. channels:       	256
	Bandwidth:          	20 kHz
	Sensitivity:        	7 nV/Sqrt(Hz)  
 
5.  Time Domain Sampler (TDS)
    
   Fast Sampler
	Inputs:             	2 of Ex, Ey or Ez
	Sample rate:        	up to 120 ksamples per second per channel
	Memory:             	2 Mbits
	Sensitivity:        	80 microvolts (RMS)
	Dynamic range:		90 dB
    
   Slow Sampler
	Inputs:             	4 of Ex, Ey, Ez, Bx, By or Bz
	Sample rate:        	up to 7.5 ksamples per second per channel
	Memory:             	2 Mbits
	Sensitivity:        	80 microvolts (RMS)  
	Dynamic range:		90 dB

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