vPAR - News
March 1, 2005
Michael Oxner


March 1, 2005

Version 2.0 is released! Two requests were made to increase the available glidepath span. Built in, Version 1.x was made to handle up to a 7° glidepath, which is sufficient for anything I've seen. That was until two guys from Switzerland asked me about it. Daniel Novet sent me an approach chart from their area which showed an initial altitude of 17,000 feet, and a glidepath of 11°. While I knew that the 17,000 feet was too high for vPAR to see the aircraft in the PAR displays, but it wasn't until I tested vPAR's apparent inability to plot higher GPAs properly that I decided to look into it. I found a few issues with the math that I used in plotting and just had to fix them. Thanks to Daniel's suggestions, I worked on a few more features. In the process of doing all of this, I put together a few features to add to the Transponder, too. And not to be left out, the old QuadRadar Analog has had a few minor enhancements, as well. Here are the lists of changes for the three programs. You'll see that despite the outwardly similar appearances, there are several new items.

vPAR QuadRadar V2.0 changes include the following:

  1. Reworked glidepath calculations. There were minor errors in the old calculations that didn't show up at low GPA, but were quite evident at higher ones.
  2. A reworked PAR elevation view in both modes. The GP is now stationary on both displays, rather than changing with different glidepath angles. Here's the catch: The presentation is a little different now on both screens, and both behave differently from each other.
    A. The Logarithmic display is the most changed of the two. The angular display is now worked in such a way that the sloping surface on the left is compared with the horizontal line on the bottom, and this angle is now broken into 7°. 3.5° above the GP, and 3.5° below. If the horizon is "visible" in that angular width (ie, the GP is less than 3.5 degrees), it will be drawn as a green "floor". There are now reference lines that are 1, 2 and 3° both above and below the GP, with markings along the side to indicate what they are. Now that the angle of the GP is constant on the screen, the elevation angles are variable in a significant way: If the GPA is set high, an aircraft in level flight will show up as climbing sharply from the bottom of the elevation view to intercept the glidepath. This is simply a function of measuring and plotting the elevation angle above the radar site, and there's nothing logical I can think of to make this any different and still make sense.
    B. The Linear plot was revised to alter the spacing of the altitude lines as the GP increases. The altitude increments will, therefore, be different at different GPAs, always staying close to ten divisions, and the increment being higher at higher GPAs. The altitudes are marked on the right hand side of the display. This has the effect of reducing the resolution of the display on the vertical axis as the GPA increases. In this view, the horizon will always be the horizontal line at the bottom of the elevation display, as before.
  3. The calculations for plotting aircraft elevations as well as angular elevations were corrected, as with point 1, but in a slightly different way. These were the hardest areas to fine tune and ensure they were correct.
  4. The LAW line plot was reworked on both displays to cover some errors similar to points 1 and 3 that were particularly noticeable at higher GPAs.
  5. The glidepath comboboxes in the Approach Editor and the PAR Setup screen were expanded to include values of 0.1-15 in 0.1 degree increments, 15-20 in 0.5 degree increments, 20-25 in whole degree increments and a 30° entry. Manual entries are also acceptable, as before. Anything above 30 will be replaced with 30.0. 
  6. Servoing the GP has changed. To aid in adjusting the GPA quickly over the new, wider range, new shortcut keys and menu items were added to the "Display" menu. In addition, it was decided that the servoing of the GP and FAC should be similar in that <CTRL>+<ARROW KEY> is now used to make 0.1 degree changes for both, and <SHIFT>+<ARROW KEY> is now used for 1.0 degree changes.
  7. Added Extended Centerline, a facility which allows the user to add an extended runway centerline along the currently set final approach course to a specified distance on the Traffic screen which may extend well beyond the PAR Block and the PAR range. The color is independently set so it can be different from other map colors. Its length is set on the Traffic Setup screen. Preset values in 5NM increments to 50NM are available, though any integer can be typed in the box. Any non-integer will set the value to 0. If the user sets it at 0, it will not be drawn.
  8. The Connection Manager is no longer a modal window. This means the user can open the Connection Manager and view its contents, then close it, or it can be left open without forcing the user to close it to make changes to or interact with the program. This allows a continuous display of those connected without interfering with program use.
  9. PAR, ASDE, and Traffic Setup dialogs, as well as the Connection Manager and Approach Editor windows may be repositioned. Especially with the new Connection Manager window, this may lead to windows being repositioned off screen in multiple monitor environments, as well as by inadvertent cursor movements. Under the Window menu, each of these windows have a "reset position" menu item which allows for quick and easy resetting of position to the top-left corner without having to edit the INI file.

vPAR Transponder V2.0 changes include:

  1. Last IP used is now saved in the INI file and will be reloaded the next time the program is run. Useful for repeated connections to the same controller.
  2. The IP boxes where controller IPs are entered have been replaced with comboboxes. These boxes will contain 10 user defined IP addresses to allow quick entry of common IP addresses. See point 3.
  3. New button to the right of the Ident box toggles IP list editor. This will pop out from the right hand side of the window, much like the Approach Editor pops down from the bottom. The listbox contains currently saved IPs, as they appear in the comboboxes. Enter an IP in the box above the Add button, then click the Add button to add the IP to the list. To remove a saved IP, highlight the IP in the listbox (by clicking on it), then click the remove button. There is no undo. This editor can be closed by clicking the "Close Editor" button, or by clicking the "Edit IP List" button that was used to open the editor. When the editor is closed, the IPs in the listbox will be saved to the three controller IP boxes' dropdown lists. These lists will be saved to the INI file when the program is shut down.
  4. There is a new IP checking routine that will prevent errors in the IP address boxes. It checks the overall length of the string, the values between the "dots", and makes sure only numeric characters are put in. If the program detects an error, it notifies the user that there is an error (though it doesn't tell the user what the error is) with a message box, and places the cursor in the offending field when the user clicks "OK" in the message box.
  5. The glidepath combobox in the Approach Editor were expanded to include values of 0.1-15 in 0.1 degree increments, 15-20 in 0.5 degree increments, 20-25 in whole degree increments and a 30° entry. Manual entries are also acceptable, as before. anything above 30 will be replaced with 30.
vPAR QuadRadar Analog V2.0 changes:
  1. Some code was reworked and should result in better memory usage, making it somewhat more efficient.
  2. There is no some basic value checking in the approach info fields. This will turn the background in a box yellow if the value appears to the program to be an error. This is meant to call the user's attention to the data to check to ensure it is correct. It will still accept the value and use it in approach plotting. The parameters which will turn the corresponding box yellow are:
    A. Latitude and longitude values are checked against integer values. The process used to convert string data to numbers return a value that is truncated at the first non-digit character (other than +, - signs, commas and periods). If a latitude or longitude value is an even integer, which is a possibility, though slim, the boxes turn yellow.
    B. If the GPA is less than 1.0°.
    C. If the GPI exceeds 4,000 feet.
    D. If the DH is below the Elevation.
    There are no other checks, currently.
The new versions will be entirely backward-compatible with the older software and their respective setup files, including the approaches.ini file. All the new variables that are used have defaults set for when the programs are run and any changes will be saved when the programs are closed for the first time.