EPIRB-Plotter

EpirbPlotter decodes, logs and plots transmissions from digital EPIRBs operating in the 406 MHz bands.

EPIRBs (Emergency position-indicating rescue beacons) are small radio transmitters that SAR satellites and aircraft use to locate aircraft, vessels or individuals that need rescuing. They are part of the Global Maritime Distress Safety System. EpirbPlotter allows you to use your PC and soundcard to decode the data messages from these beacons and, in the case of EPIRBs with GPS position reporting capabilities, to plot their positions on a suitable chart. Current generation digital EPIRBs transmit data on channels in the 406MHz band. They also usually include a homing beacon on the frequency of 121.5MHz. Digital EPIRBs include a test facility that transmits a single test data burst that EpirbPlotter can decode. In a distress situation, EPIRBs transmit the data message every 50 seconds or so. EPIRBs transmit on one of the allocated channels that are monitored by the SAR satellites. Most current models operate on 406.025 or 406.028MHz. The modulation is phase shift but a conventional narrow band FM receiver (NFM mode) tuned to a frequency between those two values will successfully decode transmissions on either channel.

EpirbPlotter Features

EpirbPlotter decodes transmissions from digital EPIRBs using the sound card in your PC. You need a suitable UHF band radio receiver tuned to the EPIRB channels. The program decodes the received digital data and displays and logs the messages.

Signal mode - In Signal Mode, EpirbPlotter displays the raw digital signals on your PC screen in a diagnostic display which helps you to set up the system and adjust the receiver.
Message mode - In Message Mode, EpirbPlotter displays each decoded message in plain language on your PC screen. The identity of the EPIRB, the serial number and the COSPAR appoval number may be included. In some cases, a vessel or aircraft callsign may be encoded in the data. In that case these details are also displayed.
Chart mode - In Chart Mode, EpirbPlotter displays the position of any EPIRB message that includes GPS location data. EpirbPlotter charts are compatible with ShipPlotter charts.
Message log - EpirbPlotter stores all messages received and decoded in a text file for later analysis and review. The log file is time stamped.
Hex log - EpirbPlotter stores all the raw decoded data in a text file for further analysis if required.

EpirbPlotter Applications

EPIRB Users and Distributors - EpirbPlotter allows you to check that your EPIRB really does transmit the correct data when you press the TEST button. Without it, you have to hope that the test indicator light is giving you the true status of your EPIRB.
Enthusiasts; Education; Training - EpirbPlotter allows you to monitor test transmissions and to detect real distress transmissions in your area. You may be able to alert authorities to the approximate location of the beacon more rapidly than the satellite-based location system can determine the distrss position.
Rescue services - EpirbPlotter allows you to receive EPIRB digital transmissions to confirm that you are in the correct search area and as a cross check on the identity and origin of related 121.5MHz homing signals. In the case of EPIRBs with GPS, you can receive coordinates directly from the beacon without waiting for a relay via the COSPAR/SARSAT system.
Port authorities, Marinas and Flight Base Operators - EpirbPlotter logs all EPIRB test transmissions and will immediately alert you to any inadvertent distress activation within your coverage area.

Requirements to run EpirbPlotter

Pentium level PC running Win95/98/Me/2k/XP with compatible sound card
A UHF band radio receiver with NFM mode. The receiver must be tuned to the EPIRB channels. The receiver audio output must be connected to the Line-In connector on your PC. Because EPIRB messages are transmitted on UHF, the beacon must be within line of sight of the receiver in order for the signals to be received.

Download EpirbPlotter

EpirbPlotter can be downloaded freely and comes in a self-installing exe file. The file size is a modest 600 kb.

Download EpirbPlotter (version 2.1) Now.

Registration of EpirbPlotter

EpirbPlotter can be freely downloaded and used for 21 days. After that time it must be registered. Registration can be done swiftly and securely on-line and costs only Euro €25 (plus VAT for EU residents) for personal use. A higher fee applies to professional or commercial use of EpirbPlotter. We strongly recommend that you ensure that EpirbPlotter performs to your satisfaction before registering.

Register EpirbPlotter Now.

Important Warning

Digital EPIRBs include provision for self testing. This testing includes a live transmission that EpirbPlotter can decode and display. Because the test transmission occupies airtime on the distress channel, it is of the utmost importance that you do not make repeated self tests when evaluating EpirbPlotter. The safety of life may depend on you following the published guidelines for testing digital EPIRBs.

Disclaimer

There are considerable variations in the legislation concerning radio reception in the different administrations around the world. It is your responsibility to determine whether or not your local administration permits the reception of EPIRB messages. It is specifically forbidden to use EpirbPlotter for any illegal purpose whatsoever. The existence and the availability of EpirbPlotter is not to be construed as an incitement to commit any unlawful act. It is for use only in those states and regions where such use is permitted.

Disclaimer

EpirbPlotter code is reliability tested to an extent that is adequate for entertainment and educational use but is neither warranted nor tested for any operational use including but not restricted to any situation where the safety of life is in jeopardy.