it may be inferred that a drift of 1 knot will not change the shape 

 of the spectrum materially nor will it shift the frequency of maximum 

 energy very much. However, a drift of several knots could make a signifi- 

 cant difference, and this problem should be looked into. 



In view of this evidence, there is some basis for confidence in 

 the SPLASHNIK as a wave measuring device. It is, however, desirable to 

 secure further verification under better controlled experimental conditions. 

 To this end, the U.S. Navy Hydrographic Office is conducting an independent 

 investigation of the SPLASHNIK, with a probe fixed to a platform in the 

 open ocean as a standard. 



PROPOSED IMPROVEMENTS 



Plans are being made to replace some of the electronics of the 

 SPLASHNIK with parts of better quality so that it may be used as a more 

 accurate research tool. This will probably necessitate cost changes that 

 may remove the "improved" SPLASHNIK from the category of "disposable item." 



It is intended to replace the present transmitting system with a 

 conventional type FM telemetering transmitter which is capable of carrying 

 several channels of sea state information by FM subcarriers. The trans- 

 ducers will be a precision accelerometer and a vertical gyro which measures 

 the tilt of the raft (equivalent to measuring roll and pitch on a ship) . 

 The vertical gyro will be used to correct for the tilt of the SPLASHNIK, 

 by eliminating the horizontal and gravitational components in the apparent 

 vertical acceleration measurement. The final recording will be a true 

 vertical acceleration. All such information would be received, demodulated, 

 and recorded on tape. The anticipated accuracy of such a system (exclusive 

 of the tape recorder) is expected to be within 1 percent of full-scale 

 signal. 



The SPLASHNIK will be further outfitted with a fin that orients 



14 



