IvAc 2 sector system

The sector system in IvAc 2 implements the following major changes:

  • 3D definition of each sector, for traffic detection and WebEye display.
  • The ability to combine and split sectors without reconnecting or changing frequency - subject to FSD upgrades
  • The ability to activate and deactivate sectors individually - subject to FSD upgrades

Sector definition


A position is an individual controller connected to IVAO. Theoretically a position will be able to activate a number of sectors simultaneously which will be individually visible online. Positions are defined in atc.xml in the root FIR folder. Each position is composed of the following:

  • Position ID - will be visible in FSD
  • Long ID
  • Short ID
  • Frequency
  • Radar centerpoint Lat/Lon
  • Radar range
  • Available to log on with
  • Callsign
  • Label design
  • Theme
  • Preset

Positions are required to maintain compatibility with legacy clients.

<atc id="AFXX_NW_CTR" long="ACCYN" short="YN" freq="131.100" lat="N0505405" lon="E0042904" range="250" avbl="true" callsign="Somewhere Radar" label="acc" theme="acc" preset="y-acc">
        <sector id="Y"	active="true"	fir="AFXX" />
        <sector id="N"	active="true"	fir="AFXX" />
        <sector id="APP"	active="false"	fir="AFXX" />


A sector is an indivisible block of airspace which may be activated. Sectors are defined in sectors.xml. Each sector is composed of the following:

  • Sector ID
  • FIR
  • Sector Name
  • Radio Callsign
  • Frequency
  • Type (DEL, GND, TWR, APP, ACC, FSS)
<sector id="Y" fir="AFXX" name="Yellow sector" callsign="Somewhere Radar" freq="125.550" type="acc">
  <volume id="Y_Sect_1" />
  <volume id="Y_Sect_2" />

The sector is defined by one of more volumes of airspace.


A volume is a polygon with a upper and lower level that defines the airspace of a particular sector. A sector with 2 different upper/lower levels such as Y sector would have two volumes.

Volumes of separate sectors may overlap and the smallest volume will be considered. Reference to the diagram above, in Y sector there is no need to cut out the APP airspace.

Note that DEL & GND sectors don't have volumes as they are linked to the aerodrome reference point & transfer conditions are different than between airborne sectors.

<volume id="Y_sect_1" fir="ABXX" bottom="000" top="999">
  <point lat="N0494918000" lon="E0041835000" />
  <point lat="N0494918000" lon="E0041835000" />
  <point lat="N0494918000" lon="E0041835000" />


Preset = Map configuration

  • Map(s)
  • Centerpoint
  • Zoom_Level
  • Theme

Position = User connection to IVAO

  • FSD Connection
  • Voice Channel
  • Preset
  • Sector(s)

Sector = What pilots / controllers see

  • ID
  • Frequency
  • LOA
  • Volume(s)
  • Adjacent sector(s)
  • Sub sector(s)

Volume = Internal

  • ID
  • Upper level
  • Lower level
  • Lat / Lon Points