Psaros is a program which has been created to allow the prediction of tides using the harmonic method. The program is designed for use on the Psion Series 3a and 3c handheld computers.
It features:
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the display of daily and weekly tide curves; |
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a monthly tide envelope curve; |
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the calculation of high and low tide times for day, week and calendar month; |
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all of the above for user selection of port, date and time zone. |
Extra ports and time zones may be added to the Psaros database as required.
The Day view displays a great deal of information in a small space. The banner at the top of the screen shows the name of the port for which the currently displayed results have been calculated. The upper left side of the display shows the date, time and time zone for the results. Below this is displayed the calculated height of the tide at the displayed time, its units, and an indication as to whether it is rising, falling or slack.
Below the current data display lies the table of the tidal extremes for the current day. The left side column shows the tide type (high or low), the central column shows the time at which the extreme occurs, and the right side column gives the tide height in units of the current port.
Dominating the right side of the screen is the height curve for the day. The x-axis of the graph shows time, in hours, starting at midnight. The y-axis shows the range of the tide in the current units. The range displayed on the y-axis is adjusted for the tidal range of each port in the database required.
The week curve view extends the concept of the day curve to the full week. The y-axis of the display shows the same range and annotation as in the day view curve. The x-axis covers the seven days of the week beginning on the currently selected day.
The week table view shows the type, time and height of all tides for the week beginning on the current day.
The month view enables the generation of a set of tide predictions for a complete calendar month. The predictions are stored on the Psion in a file with the default file name generated from: the first three characters of the location name; the three character short name of the month and; the final two digits of the year. The file has the wrd file type and is stored in in the \WRD directory on the internal (M) disk. So, for example, the default file generated for the port of Dover, for September 1997 is M:\WRD\Dovsep97.wrd. The file contains: the name of the port for which the results have been calculated; the units of the tide heights and details of each tidal extreme. The tidal extreme details contain: the type (high or low), the date and time at which it occurs, the time zone in which the results are presented and the height of the tide. The month file may be edited to the users requirements using the Psion Word editor.
In addition to the generation of the file of tidal extremes for the month, this view also displays the envelope curve of the extremes. This curve effectively shows the range of the tide at any time during the month and is useful for gaining an understanding of when the spring and neap tides occur, and when in the month tides might pass above or below certain levels. Such information is useful for guiding further examination using the week curve and day views.
Copyright © 1997 Tim Willis
ALL RIGHTS RESERVED.