vPAR QuadRadar - Traffic Display
March 1, 2005
Michael Oxner


By far the most noticable changes in vPAR occured here in the Traffic display. The original version included a limited traffic display which was based on an older, analog radar display. It supported limited range capability, no Mode C or other data associated with today's digital radar screens, no color variations and no background map. Surprisingly, I received no negative feedback regarding the program lacking these features. I'm sure many who have used the program would have wanted these features in the display. I know I did. In fact, I actually had some people write to me asking for the resurrection of the old analog beast, and ended up doing just that. Anyway, here are the new version's capabilities.

Traffic Display Image This is a quick look at the Traffic display. Details can be changed in the display, as mentioned below in the Setup section. Here's a run down of the items.

First off, the targets are now a digital representation of the position of the aircraft. In Canada, where I am, the display shown above is not all that dissimilar from what is used in the civilian world on the ATC screens. A hexagon shows the target with dots indicating trail history behind. The size and color of the targets can be altered, as well as the color and number of history trail dots, can all be changed in the Traffic Setup screen detailed below.

The data tags I'm sure will be a welcome addition. When working a PAR position you often have more than one target on your traffic display. ATC has, myself included, successfully used "tag-less" displays in the past, but we have the technology now. The Ident entered into a pilot's vPAR Transponder will be the aicraft ident in the tag, the current Mode C readout in standard 3-digit format indicating hundreds of feet, as well as the groundspeed, in tens of knots, are the normal items displayed. As on the Canadian civilian radar screens, I have added the VMI (Vertical Movement Indicator) and VMR (Vertical Movement Rate). The VMI in real life is an up arrow or down arrow, but here it's a + or a - depending on whether the aircraft is climbing or descending. Also like the Canadian screens, the VMR is calculated over four updates and displayed only if it is 500 fpm or greater. Aircraft climbing or descending slower will still show changing Mode C readouts, but no VMI or VMR. Tag direction, leader line length, color and text size are also user-adjustable. Another new feature is the addition of Predicted Track Lines, or PTLs. Activated by hitting 'P' on the keyboard, the lines will be drawn in a user-selectable color and time frame to show where each aircraft will be in a given time frame if it continues on its present track at its present speed. The time frame is determined as discussed below in the Setup screen. 'P' will act as a toggle, turning the lines on if they're off and vice versa. There is also a automatic "time out" for the drawing of these lines. By default, the lines will turn off automatically after 4 updates. This "auto clear" can be turned off so the PTLs will remain on until toggled off.

The Sector Map support for Traffic and ASDE screens is meant to read ProController/ASRC sector files already in existence. This allows you to load your current files in vPAR. Individual features have selectable colors (except GEOGRAPHY which is specified in the sector file) just as ProController and ASRC allow. The symbols are different (like VOR's, NDB's, etc) in these two programs, so be aware of what you're looking at. Another feature shown above is the 5-sided figure denoting the area visible on the azimuth display of the PAR window. This "PAR Block" is redrawn depending on the PAR range selected, as well as the PAR window dimensions as discussed on the PAR Display page.

The range displayed is adjusted using F11 and F12, just as with ProController and ASRC or by use of the Display menu items. "Ranging out" will increase your range by 25%, and "ranging in" will reduce it by 20% of the displayed range. This will provide you with even steps. 100NM ranging out goes to 125NM (100*1.25=125), and ranging in will take you back (125*0.80=100). Also, you may wish to "decenter" your radar display, so you can look further to one side than another. To pan the display around, all you have to do is right-drag the mouse cursor within the Traffic display and you'll move the center around. The screen will be redrawn when you release the right mouse button. When you close vPAR, this "offset" is saved as well. If you decenter and wish to reset to the map center, press the <F9> key.

If you want to determine the range and/or bearing between two points displayed on the screen, the Range/Bearing Line, or RBL, will do this for you. Hitting 'R' will initiate the function. The next two clicks on the Traffic window will then determine the start and end points of the RBL. After the second point is selected, the line will be drawn and range (in nautical miles including tenths of a mile) and bearing (in whole degrees magnetic) will be written near the start point of the RBL. Note that changing range, panning the display or clicking outside the Traffic window (causing it to lose focus) will all terminate the RBL function. The RBLs will be anchored to the display where they were drawn, so if you change range or pan, the RBLs will remain where they should be. To clear all RBLs from the display, double click within the Traffic window.

In Version 2.0, a facilty to add an extended centerline was added. Accessible in the Traffic Display Setup window, detailed below, the user can now have vPAR draw an extended runway centerline in 5 NM increments out to 50 NM, if desired. The color is configurable separately from other map features.

One last item to mention: The old version and the original beta copy of this program with the old name both displayed a pilot if he was connected, regardless of range. All you had to do is decenter, or range out, far enough to see him. Realizing how silly this is, a "radar horizon" has been incorporated into the Traffic Display. Now, if you show an aircraft connected to vPAR, he may not show if he's far away, or if he's down low. If he's connected and you think he should be showing, you can use the Connection Manager to confirm his position, with geographic coordinates, range and bearing. This is cheating, though. It should only be done as a diagnostic tool in the event of a suspected problem.


Traffic Display Setup

Traffic Setup Image Next is the Traffic Display Setup Dialog. The first box displays the path and file name of the currently displayed sector file. To select a sector file, click the "Select" button, then navigate to the file with the standard Open File dialog and select it. The file name will automatically appear in this box if it is successfully loaded and the Traffic Display's title bar will reflect the change. The map will be loaded right away, also.

Next, the Range rings. Personally, I'm not keen on them, but I know some folks are. They're back. Selectable spacing this time. 0, the default value, means no rings. You can select rings in 5 NM increments up to 50 NM spacing. They will cover the displayed range and their color is selectable.

Under Sizes, the Targets spinner changes the size of the targets. The Symbols spinner changes symbol size for VOR's, NDB's, Airports and Fixes, if they're in the sector file and displayed. Trail History adjusts the number of trail dots, from 0 to 50. Remembering each update in the Traffic display is 5 seconds, the default value of 12 dots reflects one minute of trail time.

Underneath this section is the setup related to the Predicted Track Lines (PTLs). The length spinner allows you to choose between 1 and 20 minutes for track prediction, and the checkbox below that determines the state of the "Auto-Clear" feature. With the Auto-Clear checked, the PTLs will turn themselves off after 4 updates. The PTLs will remain on until toggled off if the Auto-Clear is unchecked.

Data Tags allows you change the size of the text in the tag, the direction of the tag with respect to the target, and the length of the leader line that connects the target and the tag. Data tag direction can be changed by use of the NUMPAD keys. Tag direction changes made with the dialog box affect all tags on the Traffic display, and use of the NUMPAD keys affects Traffic tags only while the Traffic window has focus. If PAR has focus, NUMPAD keys will not change tag direction, and if ASDE has focus, the ASDE tags will be changed instead. Just click on the Traffic window before pressing the desired NUMPAD key to change Traffic tags.

Map Feature Selection is pretty straight forward. You simply check the box next to the item if you want it displayed. Currenlty, selecting SID or STAR shows all SIDs or STARs. Labels for individual item groups are selectable separately.

The new Extended Centerline feature is adjusted as the last item in the bottom right hand corner. Setting it to zero draws no centerline, while putting a value in there will tell vPAR to draw this reference line. This comes in handy when vectoring an aircraft to a long final outside the PAR's range.

Lastly, the color selection process. Simply select the item you want to change in the drop-down list, and click the "Select Color" button below. This will open the standard Windows Color Selection Dialog and you can then select the new color for the item you chose to change. There is no "undo" function.