Modifications to pressure data 
To establish realistic gauge depths relative to the (collection) mean sea 
surface, the barometric (gauge 616) mean value (in meters of water) was 
subtracted from the pressure gauge mean value (in meters of water). When 
the (positive) gauge depth relative to NGVD was added to the barometrically 
corrected gauge mean, the record should have reflected the tide plus any setup 
or setdown from wind or radiation stresses. However, this was not what was 
observed. Mean pressures from both gauges 2704 and 2304 seemed low. 
High tide didn't get very high above NGVD, and low tide was much lower. 
This was further pursued in an effort to determine an accurate estimate of 
gauge depths by comparing means from gauge 2704, from the 2703 pressure 
gauge, and from predicted tides. Figure E25 shows some results from 
3-21 October 1990. In the relatively quiescent days of 3-7 October, the 2703 
gauge appears to read high relative to predicted tides by about 0.10 m, and 
gauge 2304 reads considerably lower. The difference between the means is 
also plotted in Figure E25b and appears to fluctuate around 0.40 m. 
As there was not a clear pattern to explain the differences, a bias of 0.40 m 
was added to the means of both gauges 2704 and 2304 for all runs. Where this 
is incorrect, it will have a strong effect on results because all gauge depths are 
keyed on the pressure gauges; pressure and current meter wave signals were 
surface corrected using these depths, and cross spectra were normalized with 
the surface-corrected pressure auto-spectra. 
Modifications to current meter data 
In data processing, current meter data records were read in pairs, and the 
component velocities were rotated from the orientations given in the time series 
data headers into the FRF coordinate system. Additionally, the signs of the 
rotated signals were adjusted so that the cross-shore velocity (U) was positive in 
the onshore direction, and the longshore velocity ( V) was positive in the 
southerly direction. Due to the change in the coordinate system mentioned 
earlier, this is the reverse of the previous convention. 
Because of the biofouling on the Scripps open frame current meters (2711/ 
2712, 2721/2722, 2731/2732, and 2741/2742), the current meter gains for all 
current meters were adjusted to be consistent with sea surface displacement 
variance frequency spectra derived from the pressure gauge (2704 for the crest 
array, 2304 for the trough array). To do this, the PUV-test, (described in the 
“DELILAH array data analysis” section earlier in Appendix E) was used. 
To adjust the current meter gains, the mean value of the Z(c) over the 
range of (cyclic) frequencies 0.006 to 0.338 Hz was computed, and then the 
gains listed in the header records were amplified or reduced until this mean 
value was unity. Identical gain amplifications were applied equally to both 
E38 Appendix E Stationary Instrument Data 
