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Flight Tab

This is the fun part of WXtrack!  
Be warned - this mode is addictive and you will find yourself wasting a lot of time just watching it.  

The flight tab shows the ground view as it would be seen by the satellite as it traverses the earth - no receiver required - perfect visibility - in real-time!  You can choose which satellite to use - this will be the same as the primary satellite on the World Map tab, and you can select the satellite on either tab.  You can choose the direction, and existing flight image will be preserved so you don't need to wait so long for a picture to be created.

Press the Fly button to start or stop the simulation.  The last few seconds of the flight just before the current time will be pre-computed to provide a little ready-prepared picture...

Press the button labelled --> N or --> S to change the direction of the flight path.  Any image created so far will be inverted and used as the starting point for the new flight.  The direction you last used on either the Flight Path tab or the Ground Path tab will be remembered for the next run.

When the screen fills with picture lines, older lines will be scrolled to make space for new lines.  You can control how many lines are scrolled at a time with the Scroll by up-down buttons.

If you click on the Set Flight Date & Time button, you will be presented with a small dialog box to set the data and time at which the flight will start.  If you change the time, then entire flight will be recomputed, hence there is a Cancel button on the dialog.  If the flight is not running when you change the date or time, it is assumed that you would like to start the flight running.

When you switch away from the Flight Tab the simulation is stopped, and would be restarted from scratch if the Flight Tab were reselected and the Fly button pressed again.

What Time is used?

If you switch to this tab from the World Map Tab, the current clock time will be used for the flight.  If you use the Fly this pass button on the Setup Tab it will be assumed that you want to fly the selected pass from beginning to end, irrespective of the current time.  You will be confused if you select a pass near the current time, and get a flight several minutes away from the clock time.  I know I was confused!

Programming note

The way this is programmed is for the simulation to be called several times a second, and when called it tries to catch up with real-time.  If the program hasn't been running for some time, perhaps a higher priority task was executing, there may be a short gap as the simulation catches up, such as when the first few lines are pre-computed.  The routine was written in this way so that even it wasn't running for a short period lines from the simulation would not be lost.  I describe this as working in "catchup" mode.

Hardware Requirements

Experience with this mode within the user community is currently very limited, so please revisit this section in future releases.  

I would recommend that you have better than a Pentium 200MMX, and that the quality of the image produced will be substantially better if you use the large ETOPO5 file.  If you do not use the ETOPO5 file, then ensure that Options, Show Overlay is checked so that well-defined country boundaries are generated.

The CPU recommendation is based on my own tests showing that, when running a flight simulation full screen 1024 x 768 32-bit true-colour image, an AMD 266 with a Voodoo3 2000 PCI card took about 50% CPU usage, and a Pentium II 350 with a Matrox G200 AGP took about 20% CPU.  Your mileage may vary, but the program should be able to use its "catchup" way of working to compensate for the slower CPUs to some extent.  A test on a 200MMX, not full screen, showed about a 50% total CPU load of WXtrack in flight mode, together with WXSat capturing the same pass in real-time!