Low Rate Picture Transmission (LRPT)

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Weather Satellite Modes: APT - LRPT - Meteosat WEFAX

Low Rate Picture Transmission (LRPT)
LRPTWaterfall.jpg
Frequencies 137 MHz,138 MHz
Frequency Range 137 MHz - 138 MHz
Mode RAW
Modulation QPSK
ACF 0.5 ms
Emission Designator
Bandwidth 120 kHz
Location Worldwide
Short Description The Low Rate Picture Transmission (LRPT) is a digital transmission system, commonly transmitted by METEOR-M satellites, used to deliver weather images and data.
I/Q Raw Recording Download file
Audio Sample

The Low Rate Picture Transmission (LRPT) is a digital transmission system, intended to deliver images and data from an orbital weather satellite directly to end users via a VHFVery High Frequency (30-300 MHz) radio signal. It is used aboard polar-orbiting, near-Earth weather satellite programs such as MetOp (LRPT permanently deactivated on MetOp-A due to interference with on HIRS) and NPOESS (replaced with JPSS), and is currently being used on METEOR-M satellites.


Characteristics[edit]

LRPT transmits at ~120 kHzKiloHertz (kHz) 10^3 Hz Bandwidth. The signal transmits using QPSKQuadrature Phase-Shift Keying (2 bits per symbol) at 72 kBdkilobaud, kilosymbols per second (ksym/s) (72,000 symbols per second) with a raw data rate of 144 kbpsKilobits per second (kbps). The datastream is processed using a Reed–Solomon error correction, then convolution encoded, interleaved, and padded with unique synchronization words.

Each sensor on the satellite that uses LRPT to transmit its data is considered an application and provided a percentage of the transmission bandwidth in the form of a virtual channel. For example, the advanced very-high-resolution radiometer (AVHRR) imaging sensor is provided approximately 40 kbit/sKilobits per second (kbps) to transmit its three image channels, and the high-resolution infrared radiation sounder (HIRS) is provided approximately 2900 bit/sBits per second (bps).

Frequencies[edit]

  • Meteor-M N1 137.025 MHzMegaHertz (MHz) 10^6 Hz - 137.925 MHzMegaHertz (MHz) 10^6 Hz (Reported decommissioned)
  • Meteor-M N2 137.1 MHzMegaHertz (MHz) 10^6 Hz - 137.925 MHzMegaHertz (MHz) 10^6 Hz (Active)
  • Meteor-M N2-1 137.1 MHzMegaHertz (MHz) 10^6 Hz - 137.9125 MHzMegaHertz (MHz) 10^6 Hz (Launch failure)
  • Meteor-M N2-2 137.1 MHzMegaHertz (MHz) 10^6 Hz - 137.9125 MHzMegaHertz (MHz) 10^6 Hz (Failed - as of Jan. 2020)

Decoding Tutorials[edit]

Video Examples[edit]

Additional Links[edit]

Additional Images[edit]