The xir3000 plugin

Configuring the xir3000 to work with your radar

The XIR3000 uses parameters from the database file

 radR/plugins/xir3000/SDK/CANStar.ant

to decide how to acquire signals from your radar. For some radars (or "antennas", as the RTI software calls them), the digitizing parameters have already been determined and will be used when the correct antenna is selected from the xir3000 plugin menu.  If your radar is not on that list,  you have two choices:

• contact the author of radR who will be happy to add it for you
• purchase the full SDK from RTI.  Then:
  • create a .CNF file for your radar, using as a template one of the files in the folder
    

    RTI SDK 1.5.X.YYY/Misc/Antenna DB/CNF

  • run the program "Antenna Console" to regenerate the file "CANStar.ant", which must be copied to the folder "RTI SDK 1.5.X.YYY/Release"
  • use the program "RadarSample" program to determine and save the appropriate digitizing parameters for your radar; this will create a file called "usbvpfull - YOUR_RADAR_NAME.cfg"
  • copy the new files "CANStar.ant"  and  "usbvpfull - YOUR_RADAR_NAME.cfg" to the folder
    

    radR/plugins/xir3000/SDK

Automatically loading the XIR3000 plugin

To have this plugin automatically loaded each time you run radR:

• select "Load this plugin when radR starts" from the plugin menu (see below)
  and
• answer "Yes" to the question "Save parameters and GUI configuration" when you exit radR.  (Note:  just saving a plugin's configuration from its menu does not save its "autoload" flag)

Choose the XIR3000 as a source

From the player window, select the plugin as a source:

If this succeeds, the player window will look like this:

If it fails, an error message will be provided.  Some causes for failing to open the XIR3000 device are:

• XIR3000 device not connected to computer or radar, or is not powered up
• the radar is not transmitting
• the wrong "antenna" was selected
• the digitizing parameters for the radar have not been correctly determined.

The most likely problem is that the trigger pulse is not being detected.

There are several digitizing parameters which you can control from the XIR3000 plugin menu:

• antenna selection: defaults to "Decca BridgeMaster E" and chooses a set of digitizing parameters from the RTI database.  Changing this selection causes the radR XIR3000 USB port to restart.  If you are playing from the device, you may need to hit play again a few times after changing this selection.
  
• azimuth resolution: selects the number of pulses per sweep (or "scan") acquired from the plugin by radR.  The maximum, 4096, is a limitation of the XIR3000 hardware.  These pulses are "evenly spaced" around the sweep, as much as possible.
  
• sampling rate:  this determines how quickly, in millions of samples per second, the analog radar video signal is converted to 8-bit digital samples.  The sampling rate determines the possible sizes of range cells, which are obtained by "dividing" this sampling rate by integer values.
  
• range cell size: this determines the radial dimension of the volume of space represented by a sample.  It is derived by "dividing" the sampling rate by an integer value.  If you do not see a suitable choice among these sizes, try changing the sampling rate (above) and opening this menu again.
  
• video gain and trigger offset: these are set by numerical "Controls", rather than by selection from a menu.
  
  The video gain determines how much amplification of the incoming radar video signal is performed.  Please note that setting the gain too high will lead to saturation (i.e. sample values of 255)
  
  The trigger offset determines the waiting time between detection of a trigger signal and the start of video digitizing.  If it is set too low, you will see a dark hole at the centre of the data.  If it is set too large, you will be missing echos from very short ranges.  Ideally, adjust this parameter until the dark centre hole has just disappeared.  Alternatively, you can set it using a target of known range to the radar.

XIR3000 Plugin Interaction with the RTI antenna database

When you open the XIR3000 device, the digitizing parameters for the selected antenna are loaded from the file:

 radR/plugins/xir3000/SDK/CANStar.ant

Most of these parameters cannot be changed with the radR GUI (they affect whether or not a signal is properly obtained, not how it is processed). However, video gain and trigger offset can be modified and, optionally, resaved to the database by using choices from the xir3000 plugin menu. You may also reload the original values for these parameters from the database (unless you have overwritten them by resaving.)

Sampling rate and azimuth resolution are not stored in the RTI database, but rather in the file:

radR/plugins/xir3000/xir3000.conf.R

Values for these parameters are resaved to the file if you either "Save this plugin's configuration" from the xir3000 plugin menu, or if you quit radR and answer "Yes" to the question "Save parameters and GUI configuration".

> XIR3000$ant()

## outputs a full list of digitizing parameters

> XIR3000$ant(trge = 0, negvideo = 1) 

## sets digitizing to begin on rising (not falling) edge of trigger pulse; indicates video signal must be negated
## Note: an incorrect value of trge will result in loss of data within a fixed distance of the radar, regardless
## of the range cell size.