Discontinuities would interfere with spectral analysis of the signal and cause 

 artificial oscillations in the numerical model. 



57. To obtain a continuous time series, the values of m were obtained 

 from NOS* for June through September for tidal Station 33 and averaged 



(Table 2). The result, 3.09 ft, was added to each de-meaned depth series to 

 produce the tidal time series relative to MLLW. 



T(t) = D(t) + 3.09 (2) 



Error checking 



58. To validate the supposition of constant average sea level through- 

 out the harbor, monthly means relative to MLLW were also calculated for each 

 tide gage. Means, the average mean and the difference in means (A) between 

 months, are listed in Table 2 for the NOS tidal Station 33 and the CERC tide 

 gages. Direct comparison is valid only for those months when the gage was 

 operational for nearly the entire month. 



59. With the exception of TG2 , which failed before recovery, the cumu- 

 lative average water levels at each station are within 0.03 ft. The individ- 

 ual monthly averages show more variation, though the differences between 

 months indicate that the same trends are occurring at each site. 



60. To verify clock accuracy (nominally ±1 ppm) , deployment, recovery, 

 and shutoff times, as recorded in the field, were checked against the 

 indicated times of the data sets . Deployment and recovery are apparent from 

 pressure records and shutoff time from the last time word in the series. 

 Agreement within the 3.75-min sampling interval was considered adequate veri- 

 fication. Verification was not possible when the gage was not operating at 

 recovery, as for TG2 . 



61. Tidal accuracy is addressed in more detail under Part IV. 

 Output 



62. Two files from each data set were generated. The first, TG*W, was 

 of the entire time series. The second file, TG*S , was of a "specified" time 

 interval for which current meter data were available. The * symbol refers 



* Personal Communication, Wolfgang Scherer, February 1988, US Department of 

 Commerce, National Oceanic and Atmospheric Administration (NOAA) , NOS, Sea 

 and Lake Levels Branch. 



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