Keeping Track of the Time Mode








This document defines the Zebra time modes, and trains the user to identify what time mode Zebra is using and what time the displayed data were taken.


Time Modes

As discussed in General Setup, there are two time modes in Zebra:
  • Real-time mode: Displays the most recent data in each enabled directory. In real-time mode, the reference time is set to the time that the most recent data file was obtained.
  • History mode: Displays the most recent data from each enabled directory before a specified reference time. In history mode, the reference time is a constant that is arbitrarily set by the user.
The reference date and time is displayed in the upper left-hand corner of the main windows. There are two ways to find out whether Zebra is in real-time mode or history mode.
  1. If the font color of the reference time is yellow, then Zebra is in history mode.
  2. The current time mode is displayed at the top of the "Data Available" menu (for information on the "Data Available" menu, see General Setup).
In order to change the time mode or the reference time, activate the time widget. This is done by selecting "Time Widget" from the "Zeb Conrol Options" menu (see General Setup). Within a few seconds, an outline of the widget shows up on the screen. Simply move the outline to the desired position, then click with the left mouse button to draw the window.

Fig. 1 contains a diagram of the time widget. In order to switch Zebra to real-time mode, use the mode selector to select "Real Time." Then, iconify the time widget or click on the "Dismiss" button to close the window. In order to switch to history mode, one needs to input a reference time first. This is done by either toggling the day, month, year, hours, and minutes arrows until the desired reference time is displayed and clicking "Set Time"; or by clicking on the reference time box, deleting the current box contents using the "backspace" key, and typing a new reference time (UTC) in the format DD-MMM-YY, HH:MM:SS. Once this is done, select "Set Time" to put Zebra in history mode.

Once in history mode, if one wishes to change to a different reference time, the above procedure can be repeated, or the "Skip" function can be used. To use the "Skip" function, input a time increment in the "Skip" box and select the desired units (hours, minutes, seconds, etc.) using the small pull-down menu to the right of the box. Then, by clicking the forward or backward arrows, the reference time is shifted by the given increment and the history time is automatically reset.


Fig. 1: Diagram of the Time widget, showing these five components: (1) the reference time (for history mode only), (2) the "Dismiss" button, (3) the "Skip" function, (4) the time mode selector, and (5) the mode display.


Overlay Times

Once the time mode is set, don't be fooled! The reference time is NOT necessarily the actual time that each displayed field was observed. In order to determine the actual time of each field, simply type the letter "t" while the mouse cursor is located in big. This activates the "Overlay Times" widget (Fig. 2). The widget contains a table of the directory each icon represents (under "PLATFORM"), the field being displayed, the altitude of the horizontal cross-section, and the actual time and date that the data were obtained. In the case of remote sensing data, the times represent the beginning sampling time. For example, radar volumes are referenced by the time at which the volume scan was initiated.

Each time the display changes, the overlay times widget is automatically updated. Thus, keeping the overlay times window open during your MountainZebra session is highly recommended, as it will help eliminate confusion.


Fig. 2: The Overlay Times widget.

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curt@atmos.washington.edu