Screen Shots

The following images show most of the interesting screens generated by InstantTrack.

Here is the main menu. It comes up instantly when you start the program. (Sorry if this web page doesn't come up quite so instantly!)

Notice the data for seven favorite satellites displayed across the bottom row. Once you've set up your location and updated the Keplerian elements, this bottom row display shows the azimuth and elevation for the satellites you prefer, in realtime, as soon as you start the program. AO-10 is in yellow, because it is above the horizon right now.

If you select the Realtime Track 1 Satellite (Text Screen) option, here's what you see:

Notice the bottom row display is still there. In addition, you see a full screen  of information on the one satellite you picked, all updated rapidly in real time. The top few lines give the information you need for radio operation, for your location (here the default station is N6NKF) and for up to three other locations (here we've picked W1AW from the station list). The next few lines give information about where the satellite is (the subsatellite point) and when it will next cross the horizon. The subsatellite point is given in lat/long and in grid coordinates, but the easiest way to understand the location is with the text description relative to the closest city in InstantTrack's database of 1794 cities. The cartesian (X,Y,Z) coordinates of the satellite are given, and the astronomical coordinates too. Many of these displays can be switched off if you find them distracting.

By the way, here's how you picked the satellite to display:

InstantTrack keeps a database of up to 200 satellites, and you can pick by name or by number. On this menu the satellites that are above the horizon are highlighted in yellow, in realtime.

If you select the Realtime Track 1 Satellite (Map Screen) option, you'll see this:

A lot of the same information as on the text screen is visible here, and you can switch to other text fields with a keystroke. But the main attraction is the map, of course. The default view is the cylindrical projection seen above. The white line represents the footprint of the satellite (very large here since we're looking at AO-10, a high orbit satellite). The purple line represents the terminator. A white dot (at the very right edge of the screen) represents the satellite. You can ask for a ground track showing the path of the satellite for the next 1 to 60 orbits (not shown here).

With a single keystroke you can switch to the orthographic projection view, like this:

In this example, I have fast-forwarded to a time when the satellite was off the tip of Florida, to get a prettier map display. See how much easier it is to understand the footprint, which is again shown by a white line. It's just a circle! That's because this projection has no distortion. Unfortunately this map takes longer to draw, so on very old computers you may find it less than Instant. (Just about everything else in InstantTrack is so fast you won't notice the delay, even on the oldest, slowest PC!)

If that's not enough, there's a third view. This is a plan view of the orbit itself:

The orange circle represents Earth, and the little X is your location. The ellipse is AO-10's orbit, and the two little diagrams on the left and top represent edge-on views from the left and the top. The red dot is the satellite, and the arrows indicate which way the antennas are pointing (if you've entered the satellite's attitude information).

There is one more view, of the satellite's location against the stars:

The line represents the horizon. You can see the satellite, represented by a red dot, is just barely above the horizon. The white dots represent stars, from InstantTrack's database of the 940 brightest stars in the sky. Notice that the default text information on the bottom row switches to the astronomical coordinates, which are probably more familiar to stargazers.

That's it for the graphics screens, but there's more to see on the text screens. If you select Satellite Position Table (Ephemeris) you pick a satellite and then answer a couple of prompts, like this:

... and then you get a table of the satellite's future passes at your location:

You can switch between several different formats for this screen. You can also capture this information to a file or to a printer. You can see/capture/print screen after screen manually, or you can run the predictions up to a certain future time and stop automatically. This allows you to plan your operating schedule in advance.

If you select Satellite Visibility Schedules, you get to make a further selection from these options:

These options provide various planning tools for various purposes. If you know which satellite you want to use and just want a quick overview of the upcoming passes, select Multiple Days for Single Satellite, and see this:

Each line represents a day, and each character represents 15 minutes. You can see at a glance roughly when this satellite will be available. You can see more days with a keystroke.

If you're not so sure about which satellite, you can select Multiple Satellites for Single Day, and see this:

Here each row represents a different satellite, chosen from a group you can configure. There is a lot of information here! It shows pass times for the next day for 20 satellites. You can see another day's schedule with a keystroke. By the way, on almost every screen you can switch from UTC to your local timezone with a keystroke.

If you're trying to work a specific other station on a specific satellite, select Multiple Observers for Single Satellite, to see this:

This shows when the satellite is visible at your station, and at up to three additional locations you can specify by selecting from a menu, or by city name (Tokyo is shown here), or by latitude and longitude (20 degrees North by 150 degrees West is shown here), or by grid square (not shown). You can easily pick out when there is a mutual window for any combination of the stations.

Sometimes the satellite designers set up the frequencies so it's possible for a signal from one satellite to be received directly by another satellite. Sometimes this is an accident, and sometimes it's a key design feature of a set of spacecraft. InstantTrack can show you when satellites can "see" each other. Just select Multiple Satellite Co-visibility from the main menu, and see this:

This is a matrix, with satellites by number and name down the left, and satellite numbers across the top. There's a yellow dot where the satellite on the left can see the satellite on the top. There are also columns for the observer (you) and the Sun.

All this magic does require some help from you, on the Housekeeping Menu:

You will periodically need to update the Keplerian satellite elements, since they do develop errors over time. InstantTrack provides a whole menu of options to help you maintain the database of satellite elements:

You can enter elements by hand using option 8, but generally you will want to download a file containing fresh elements and let InstantTrack read the file using option 1, 2, or (usually) 3. When you read in a file of elements, they can be in either of the two popular formats, and they can be cluttered up with other text. InstantTrack finds the element sets in the file, and displays status one screen at a time:

If you need to inspect or update elements by hand, here's the screen for that:

The entries on the left can be edited. The last few (attitude, diameter, groups, and schedule) can only be updated manually, since they are not part of the published element sets. The information on the right is derived by InstantTrack to help you evaluate the elements.

InstantTrack can operate with several types of add-in or "TSR" components. Selecting Option Status (TSRs) from the Housekeeping Menu allows you to see how those components are doing. Like this:

And last but not least, InstantTrack offers many screens of online help, accessible from most screens by a single keystroke. Here's the main menu of help options available online:

The help files describe all the keystroke commands you can use on each screen. There are lots of them!

That concludes our little tour of InstantTrack's display screens.

These images are from a late beta version of InstantTrack, but the current released version looks nearly identical.

The text screens were captured on a Windows system with a high-resolution screen. Your font will probably be different, but the characters displayed will be the same. The graphics screens were captured in VGA mode, InstantTrack's highest resolution mode. Displays in EGA mode look very similar, just not quite as sharp. Displays in other video modes are much less beautiful.

Copyright 2000 Paul Williamson. All Rights Reserved.

Last updated 12 October 2000. Comments to

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