San Francisco State University Physics and Astronomy Department
SFSU Pacific Oceanography Project
Calibration of Acoustic Gain for the PSM VLA
( data files |data files |sfsu private page )

Here is the calibration for signals from Pioneer Seamount, from Lyle Gullings, U. of Washington Applied Physics Lab

									18 September 2001
To:	Jim Mercer
From:	Lyle Gullings
Subject:  Pioneer Seamount VLA Receiver; tabulation of overall system sensitivity
Enclosure:  Tabulation of Overall System Sensitivity

The gain-versus-frequency measurements performed on the overall system at
the Laboratory using the 50-mile cable simulator have been adjusted for
the results of the in-situ measurements conducted on the RONALD H. BROWN
and at Pillar Point Air Force Station during the array deployment, and
combined with the measured hydrophone sensitivity data to establish the
overall system sensitivity.  These data for the NOAA output at connector
J49 on the rear panel of the VLA Receiver chassis are provided by the
enclosure.

The Channel Gain column represents the actual measured gain for channel 2
of the system, excluding the hydrophone, but including the adjustment
derived from the in-situ measurements.  The Hydrophone Sensitivity column
represents actual hydrophone sensitivity measurements for frequencies from
10 to 1000 Hz.  Actual hydrophone sensitivity data below 10 Hz are not
available, however, I have extrapolated the measured values down to 2 Hz to
provide an estimate of system response below 10 Hz.

Considering small differences in the gains of each channel and in the
sensitivity of each hydrophone, and in the uncertainty of the measurements,
it is estimated that the tabulated values represent the overall sensitivity
for each channel of the system within +/- 2 dB from 10 to 1000 Hz. 


Enclosure to Pioneer Seamount VLA Receiver memo, 18 September 2001

Tabulation of Overall System Sensitivity
 
     Hydrophone		 Channel    	    		NOAA Output
Frequency, Hz		Sensitivity, dBv//upa		 Gain, dB	Sensitivity, dBv//upa

        2	          -245.0			    29.9			-215.1
        3	          -238.0			    37.9			-200.1
        4	          -234.0			    47.9			-186.1
        5	          -232.0			    53.9			-178.1
        6	          -230.0			    58.9			-171.1
        7	          -228.0			    63.9			-164.1
        8	          -226.0			    67.9			-158.1
        9	          -225.0			    70.4			-154.6
      10	          -223.0			    71.9   	  		-151.1	
      20	          -213.0			    76.9  	                -136.1
      30	       	  -208.0			    77.4	      		-130.6
      40	          -205.0			    77.9			-127.1
      50	          -202.0			    78.1			-123.9
      60	          -201.0			    78.4			-122.6
      70	          -200.0			    78.9			-121.1
      80	          -199.0			    79.4			-119.6
      90	          -198.5			    79.9			-118.6
    100		          -198.0			    81.4			-116.6
    200		          -196.0			    85.4			-110.6
    300		          -197.0			    87.9			-109.1
    400		          -197.0			    90.2			-106.8
    500		          -199.5			    90.9			-108.6
    600		          -200.0			    92.4			-107.6
    700		          -200.2			    92.4			-107.8
    800		          -200.2			    91.4			-108.8
    900		          -200.5			    88.9			-111.6
  1000		          -201.0			    85.3			-115.7