Inmarsat Aero

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Inmarsat Aero
Inmarsat Aero.jpg
Frequencies 1545 MHzMegaHertz (MHz) 10^6 Hz1,545,000,000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
1,545,000 kHzKiloHertz (kHz) 10^3 Hz
,1547 MHzMegaHertz (MHz) 10^6 Hz1,547,000,000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
1,547,000 kHzKiloHertz (kHz) 10^3 Hz
,3685 MHzMegaHertz (MHz) 10^6 Hz3,685,000,000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
3,685,000 kHzKiloHertz (kHz) 10^3 Hz
,3687 MHzMegaHertz (MHz) 10^6 Hz3,687,000,000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
3,687,000 kHzKiloHertz (kHz) 10^3 Hz
1,545,000 kHzKiloHertz (kHz) 10^3 Hz
1,545 MHzMegaHertz (MHz) 10^6 Hz
3,687,000 kHzKiloHertz (kHz) 10^3 Hz
3,687 MHzMegaHertz (MHz) 10^6 Hz
Frequency Range 1,545 MHzMegaHertz (MHz) 10^6 Hz1,545,000,000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
1,545,000 kHzKiloHertz (kHz) 10^3 Hz
- 3,687 MHzMegaHertz (MHz) 10^6 Hz3,687,000,000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
3,687,000 kHzKiloHertz (kHz) 10^3 Hz
Mode USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)
Modulation PSKPhase-Shift Keying
ACFAutoCorrelation Function
Bandwidth 800 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).0.8 kHzKiloHertz (kHz) 10^3 Hz
8.0e-4 MHzMegaHertz (MHz) 10^6 Hz
,1600 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).1.6 kHzKiloHertz (kHz) 10^3 Hz
0.0016 MHzMegaHertz (MHz) 10^6 Hz
,10500 kHzKiloHertz (kHz) 10^3 Hz10,500,000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
10.5 MHzMegaHertz (MHz) 10^6 Hz
0.8 kHzKiloHertz (kHz) 10^3 Hz
8.0e-4 MHzMegaHertz (MHz) 10^6 Hz
10,500 kHzKiloHertz (kHz) 10^3 Hz
10.5 MHzMegaHertz (MHz) 10^6 Hz
Location Worldwide
Short Description Inmarsat Aero is the protocol that's used to link ground stations with aircraft via Inmarsat's satellite link. This protocol carries digital voice, fax and low speed data such as ACARS and ADS-C.
I/Q Raw Recording Download file
Audio Sample
Inmarsat Aero is the protocol that's used to link ground stations with aircraft via Inmarsat's satellite link. This protocol carries digital voice, fax and low speed data such as ACARS and ADS-C.


Characteristics[edit]

Inmarsat Aero in this article is the Forward TDM link from ground station to plane. The links use OBPSK or OQPSK modulated with 600, 1200, and 10500 bpsBits per second (bps) signals. The 600 and 1200 bpsBits per second (bps) links are part of Inmarsat's Classic Aero service which is due to be discontinued in 2018. the 10500 bpsBits per second (bps) link is part of Inmarsat's Aero H and H+ services which are capable of transmitting both data (10.5 kbpsKilobits per second (kbps)) and digital voice (9.6 kbpsKilobits per second (kbps)).

The Inmarsat Aero system has both forward and return links, as well as digital voice channels.

Forward (Ground Station to Plane)[edit]

  • P-channel packet switched data TDM: 600 bpsBits per second (bps), 1200 bpsBits per second (bps) A-BPSKBinary Phase-Shift Keying (1 bit per symbol) (SDPSK), 10.5 kbpsKilobits per second (kbps) A-QPSKQuadrature Phase-Shift Keying (2 bits per symbol) (OQPSK), convolutional FECForward Error Correction R = ½, k = 7
  • Digital Voice circuit mode SCPC: 8.4 kbpsKilobits per second (kbps) A-QPSKQuadrature Phase-Shift Keying (2 bits per symbol) (OQPSK), convolutional FECForward Error Correction R = 2/3, k = 7, 10.5 kbpsKilobits per second (kbps) A-QPSKQuadrature Phase-Shift Keying (2 bits per symbol) (OQPSK), convolutional FECForward Error Correction R = ½, k = 7

Return (Plane to Ground Station)[edit]

  • R-channel slotted Aloha: 600 bpsBits per second (bps), 1200 bpsBits per second (bps) A-BPSKBinary Phase-Shift Keying (1 bit per symbol) (SDPSK), 4.8 kbpsKilobits per second (kbps), 10.5 kbpsKilobits per second (kbps) A-QPSKQuadrature Phase-Shift Keying (2 bits per symbol) (OQPSK), convolutional FECForward Error Correction R = ½, k = 7
  • T-channel TDMATime Division Multiple Access: 600 bpsBits per second (bps), 1200 bpsBits per second (bps) A-BPSKBinary Phase-Shift Keying (1 bit per symbol) (SDPSK), 10.5 kbpsKilobits per second (kbps) A-QPSKQuadrature Phase-Shift Keying (2 bits per symbol) (OQPSK), convolutional FECForward Error Correction R = ½, k = 7
  • Digital Voice circuit mode SCPC: 8.4 kbpsKilobits per second (kbps) A-QPSKQuadrature Phase-Shift Keying (2 bits per symbol) (OQPSK), convolutional FECForward Error Correction R = 2/3, k = 7, 10.5 kbpsKilobits per second (kbps) A-QPSKQuadrature Phase-Shift Keying (2 bits per symbol) (OQPSK), convolutional FECForward Error Correction R = ½, k = 7


Inmarsat Forward TDM Link[edit]

  • 600 bpsBits per second (bps): Aviation-BPSKBinary Phase-Shift Keying (1 bit per symbol) (SDPSK or Pi/2-BPSKBinary Phase-Shift Keying (1 bit per symbol)) modulation at 600 BdBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second.. Spans 800 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). of bandwidth.
  • 1200 bpsBits per second (bps): Aviation-BPSKBinary Phase-Shift Keying (1 bit per symbol) (SDPSK or Pi/2-BPSKBinary Phase-Shift Keying (1 bit per symbol)) modulation at 1200 BdBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second.. Span 1600 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). of bandwidth.
  • 10500 bpsBits per second (bps): Aviation-QPSKQuadrature Phase-Shift Keying (2 bits per symbol) (OQPSK) modulation at 10500 BdBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second. with convolutional FECForward Error Correction (Raw data throughput is 21000 bpsBits per second (bps), actual data rate with FECForward Error Correction is 10500 bpsBits per second (bps)). This is part of Inmarsat's Aero H and H+ service.


Inmarsat Aero.gif

Samples[edit]

Forward TDM Link (Ground Station to Plane)
10.5 kbpsKilobits per second (kbps) 600 bpsBits per second (bps)

Inmarsat Aero.jpg
600bps Aero.jpg

Frequencies[edit]

  • L band downlink (Satellite to Plane): 1545 MHzMegaHertz (MHz) 10^6 Hz - 1547 MHzMegaHertz (MHz) 10^6 Hz (600 and 1200 bpsBits per second (bps) signals are usually found around 1545 MHzMegaHertz (MHz) 10^6 Hz, whereas the faster OQPSK channels with 10500 bpsBits per second (bps) are found around 1546 MHzMegaHertz (MHz) 10^6 Hz.)
  • C Band downlink (Satellite to ground station): 3600 MHzMegaHertz (MHz) 10^6 Hz - 3629 MHzMegaHertz (MHz) 10^6 Hz

Check UHF Satcom for frequencies.

Decoding Tutorials[edit]

Decoding Software[edit]

Hobby Level Software


Professional Equipment/Software

Video Examples[edit]

Additional Links[edit]

Additional Images[edit]