Table 2. Note that the IHO data originate from older NOS analyses. A com-
parison study between the latest NOS and IHO/NOAA data was completed over
multiple stations.
Measured harmonic constituent amplitude values are compared by calcu-
lating a proportional standard deviation per harmonic constituents over all
21 stations throughout the domain and defined regions as shown in the following
equations.
1/ 2
L ηIHO/NOAA x , y - ηNOS x , y 2
∑ l =1 ^ j
( l l ) ^ j ( l l )
E mamp
=
(7)
2
∑ l =1 η j ( xl , yl )
L
j-
NOS
^
where
L = the total number of elevation stations within a given
region
( xl , yl )
= the location of an elevation station
ηIjHO/NOAA ( xl , yl ) = the IHO/NOAA elevation amplitude for constituent j at
^
ηNOS ( xl , yl ) = the NOS elevation amplitude for constituent j at station
^j
Measured phase values are compared for each constituent j by computing an
absolute average difference defined over a region as:
1 L IHO/NOAA
= ∑ φj
( xl , yl ) - φ NOS ( xl , yl )
m
E j- phase
(8)
j
L l =1
where
φIjHO/NOAA ( xl , yl ) = the IHO/NOAA elevation phase for constituent j at
measurement location (xl, yl)
φ NOS ( xl , yl )
= the NOS elevation phase for constituent j at measurement
j
location (xl, yl)
j-
j-
amplitude and phase of the published constituent data. The estimated measured
data error values for each tidal constituent at all 21 stations with dual measured
values in each subregion are listed in Table 3 for the O1, K1, Q1, M2, N2, S2, and
15
Chapter 4 Description and Error Analysis of Field Data
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