FLARM Range Analyzer

By analyzing data from the built-in flight recorder (IGC files), the FLARM Range Analyzer can tell you the quality of your FLARM antenna installation, based on received data.

The Range Analyzer has two modes: CARP is a new feature in PowerFLARM-based devices that continuously integrates the average range over time (many flights). The classic range analyzer uses only range data from the uploaded flights. The two different modes are described below.

CARP – Continuous Analyzer of Radio Performance

Select the latest IGC file from the device to visualize the long term range data. This data is computed over many flights and thus likely contains enough data points to compute a meaningful range. Make sure that the aircraft has flown at least 10 flights after the last CARP reset.

Since the range is averaged over all flights since the last CARP reset, a recent degradation in the installation quality might not be visible. Reset CARP or use the classic range analyzer in case of doubt. CARP is explained in more detail in this blog post.

CARP is normally reset using the connected FLARM Compatible display. For displays that don’t have this capability, CARP can also be reset using the Configuration Tool. To avoid reconfiguring the device, a config file that only resets CARP can also be downloaded here.

CARP is only available for PowerFLARM-based devices.


Classic Range Analyzer

Select one or several consecutive IGC files from the same device to visualize the range data from those flights.

The range is computed by averaging the recorded contacts during those flights only, and might thus be unreliable if a sufficient number of aircraft have not been within range.

Flights to be analyzed must have a duration of at least 30 minutes and contact with at least 5 other aircraft while flying.

Note that IGC files recorded with firmware prior to version 6.40 will show the range for both antenna A and antenna B as the range for antenna A.

Technical information

FLARM devices store some randomly chosen relative positions received from other aircraft in an IGC file. This data is then analyzed to determine the reception range. As the range depends equally on your and the other aircraft’s radio performance, which is unknown, a large number of data points must be collected. The inherent limitation of this analysis is that it can only examine and show successful receptions. Therefore it can indicate areas of confirmed performance, but can only hint at areas with no reception, as there will be little or no data from there. Based on this approach, the transmission range cannot be assessed, but reception range is a reasonable proxy for transmission range, with some exceptions. (Note that some ground-based tools for assessing the transmission range exist e.g. from Ktrax; these however only give indicative information due to a lack of calibration and also require extensive flight time.)

How can I improve the transmission range?

  • Check the Installation Manual to see if all requirements and recommendations have been followed
  • Read the Application Note on FLARM Antenna Installations
  • If you have an internal antenna, relocate the FLARM antenna to another position, as far away as possible from any metal or carbon
  • If you have an internal antenna, install an external FLARM antenna (AV-75)

Should I try to improve the “maximum distance”?

Distances beyond 12 km in one direction and much worse distances in other directions is normally a sign that the performance is not evenly distributed in all directions. Therefore, a large “maximum distance” could be bad for overall performance.

Do NOT use directional antennas. Directional antennas will make the range much worse in most directions.


This tool performs a statistical analysis of past data, based on data supplied by the user. The result of this analysis may differ significantly from actual, individual performance.

We take the privacy of your data seriously and you can find our Privacy policy here.