Zoned Tides (ZDF) format

This document describes details of the ZDF Zoned Tides format.

On this page:

Format Description

General Notes

All fields are comma delimited, there is no specification on whitespace usage between fields though. All sections should be followed by a blank line.

Sections

[ZONE_DEF_VERSION_2] or [ZONE_DEF_VERSION_3]

This is the header section that specifies the ZDF version. It has no records.

[ZONE]

This section is repeated for each zone to define the polygon in which the associated gauge(s) and correctors are applicable.

The first line contains

zone label
vertex count

Following records contain the position of each vertex with

latitude
longitude

Example:

TEXT

[ZONE] 
WGM277,5 
29.224709, -91.185916 
29.220308, -91.160837 
29.005056, -91.282961 
28.968641, -91.399733 
29.224709, -91.185916

[TIDE_STATION]

This is a list of all the tide stations referenced by zones or tide averages.

Unless otherwise specified (as in version 3) the tide files are assumed to be located in the same directory as the .zdf and take the form of "(station label).tid"

In version 2 each record includes

station label
latitude
longitude

Example:

TEXT

[TIDE_STATION] 
8762075, 29.115000, -90.206700 
8763535, 29.173333, -90.975000
...

In version 3 the record additionally includes

maximum amplitude (meters)
uncertainty value
(optional) tide file path.

Example:

TEXT

[TIDE_STATION] 
8762075, 29.115000, -90.206700, 2.0, 0.15, C:\Tides\8762075.tid
8763535, 29.173333, -90.975000, 1.5, 0.10, C:\Tides\8763535.tid
...

[TIDE_ZONE]

This defines the relationship between the zones and the tide stations.

For version 2 each record contains

zone label
station label
priority - this can be: PRIM, SEC, TER, or PRELIM; meaning: primary, secondary, tertiary, or preliminary, respectively.
time offset, or corrector (minutes)
amplitude scalar, also referred to as range corrector - this is a multiplier for the tide height to scale the amplitude
(optional) tide file path

Example:

TEXT

[TIDE_ZONE] 
CGM716, 8763535, PRIM, -24, 0.836 
WGM264, 8763535, PRIM, -36, 0.963 
...

For version 3 the tide file path is not an option, but the follow additional fields are included

tidal shift (meters) - this is a vertical shift of the tide height to be added after scaling
uncertainty - this is an uncertainty for the tidal zone

Example:

TEXT

[TIDE_ZONE] 
CGM716, 8763535, PRIM, -24, 0.836, 0.0, 0.2
WGM264, 8763535, PRIM, -36, 0.963, 0.0, 0.2
...

[TIDE_AVERAGE]

These are lists of tide stations to average for use in the designated zone. Averaging is done after corrections specified in [TIDE_ZONE] are applied.

In many cases no averaging is needed but stations are listed redundantly in this section.

Records include

zone label
comma separated list of 2 or more station labels to average

Example:

TEXT

[TIDE_AVERAGE]
CGM716,8763535,8763535 
WGM264,8763535,8763535 
...

[OPTIONS]

There are only two standard options

Outage (minutes) - if missing records, the time after which to switch to the next priority station
Interval (seconds) - final interval of tide heights loaded into the line

Example:

TEXT

[OPTIONS] 
Outage, 30
Interval, 360

Example: OPR-K354-KR-2011

This example comes from the Body and Appendices of NOAA Descriptive Report H12331.

Location of survey area, tide zones, tide stations 8762075 and 8763535 and the
time/range correctors for those tide stations.

ZDF file (version 2)

TEXT

[ZONE_DEF_VERSION_2] 
 
[ZONE] 
CGM716,14 
28.516196,-90.501009 
28.471404,-90.519688 
28.265943,-90.630658 
28.001139,-90.699347 
28.371610,-91.091603 
28.575123,-91.295343 
28.674869,-91.281683 
28.786847,-91.016701 
28.734720,-90.992780 
28.658449,-90.872902 
28.562754,-90.699401 
28.547356,-90.644364 
28.519663,-90.553010 
28.516196,-90.501009 
 
[ZONE] 
WGM264,7 
28.968641,-91.399733 
29.005056,-91.282961 
28.841561,-91.375255 
28.601696,-91.461815 
28.522274,-91.674134 
28.788473,-91.550173 
28.968641,-91.399733 
 
[ZONE] 
WGM265,7 
29.005056,-91.282961 
29.032404,-91.203049 
28.876853,-91.254013 
28.674869,-91.281683 
28.601696,-91.461815 
28.841561,-91.375255 
29.005056,-91.282961 
 
[ZONE]
WGM266,7 
29.032404,-91.203049 
29.066476,-91.098476 
28.977116,-91.103401 
28.786847,-91.016701 
28.674869,-91.281683 
28.876853,-91.254013 
29.032404,-91.203049 
 
[ZONE]
WGM276,5 
29.220308,-91.160837 
29.217374,-91.142446 
29.032404,-91.203049
29.005056,-91.282961 
29.220308,-91.160837 
 
[ZONE]
WGM277,5 
29.224709,-91.185916 
29.220308,-91.160837 
29.005056,-91.282961 
28.968641,-91.399733 
29.224709,-91.185916 
 
[TIDE_ZONE]
CGM716,8763535,PRIM,-24,0.836 
WGM264,8763535,PRIM,-36,0.963 
WGM265,8763535,PRIM,-30,0.963 
WGM266,8763535,PRIM,-24,0.963 
WGM276,8763535,PRIM,-30,1.059 
WGM277,8763535,PRIM,-36,1.059 
 
[TIDE_STATION]
8762075,29.115000,-90.206700 
8763535,29.173333,-90.975000 
 
[TIDE_AVERAGE]
CGM716,8763535,8763535 
WGM264,8763535,8763535 
WGM265,8763535,8763535 
WGM266,8763535,8763535 
WGM276,8763535,8763535 
WGM277,8763535,8763535 
 
[OPTIONS]
Outage, 30 
Interval, 360