TdB (Tides Database) is a system for recording, editing and publishing tidal data. It supports the collection, processing and publication of data from tide gauges. TdB provides all the workflow and visualisation tools necessary to produce Quality Assured tidal height information.
Raw tidal height data can be collected from tide gauges in a variety of formats and may include gauge pressure, water height, density, temperature salinity and atmospheric pressure. This is imported into TdB along with meta data such as vertical datum information, benchmarks, instrument details, photographs and other survey data.
The height data can be viewed, analysed and processed in a variety of ways. A comprehensive suite of graphical displays are used to analyse the data and compare it with other data sets. Sophisticated time series representations are available along with comparisons, concordance and Van de Casteele diagrams.
Typical operations include correcting instrument errors (clock jitter, spikes, drift) and reconciling datum/benchmark offsets.
A workflow mechanism allows multiple users to coordinate and control their work
A primary output from TdB is hourly height series. These are Quality Assured, checked and validated according to IOC guidelines. Data sets can be exported in several formats including XML.
Additional output includes Mean Sea Level (Daily, Monthly, Annually) and Tide Station Record Sheets.
TdB is built on an industry standard Oracle database and fully supports access by multiple users across a LAN. It is capable of managing a global data set (thousands of ports) for the complete time span over which tidal data has been collected (100+ years).
Standard procedures can be used for supporting the integrity of the database, maintaining backups and managing access control.
The client application runs on a standard Windows PC (XP or Vista).
The client integrates with the Caris HPD (Hydrographic Production Database).
It can also be supplied with a stand-alone host which displays the locations of ports graphically on a World Vector Shoreline or ENC data set.
Raw data can be imported directly in the following formats:
|CARIS HIPS & SIPS||.tid|
|SHOM Hourly Heights||.hhs|
A fast, flexible graph tool allows data to be rapidly displayed and manipulated. Sub sets of the data can easily be adjusted or even deleted.
Comparisons can be made between different ports and different data types. Instrument errors can be readily detected along with datum and other benchmark changes.
Anomalies in the data (spikes, flats, discontinuities) are automatically detected and indicated as part of the graph display.
Large amounts (years) of data can be rapidly scanned and assessed.
Changes to the station record are immediately and clearly indicated in the editor. A system known as ‘directed editing’ is used to guide the user in understanding and implementing changes.
All the Tide Station Record Sheets for any port are readily available for inspection.
The benchmarks and datum information for different record sheets can be directly compared.
The full station record may contain images along with specifics of each measurement campaign, installed instrument, benchmarks, datum information and so on.
Tide Station Record Sheets can be generated with whatever layout is required to fit in with existing documentation.
A managed workflow process is fundamental to providing assurances about quality and validity. The approach used in TdB is simple to understand and provides all the control needed to manage multiple editors and the publication process.
A set of port data is locked by an individual editor. Changes are made locally and only become available to the publication processes once they have been approved.
The database incorporates a set of rules which are applied as part of the validation process. These cover a wide range of checks from the ordering of time values and the uniqueness of certain names to consistency and completeness requirements.