Low Rate Picture Transmission (LRPT)

From Signal Identification Wiki
Jump to: navigation, search
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.

The bandwidth is sufficient for 3 channels from the MSU-MR radiometer. Any of the six channels provided by the radiometer can be selected to be transmitted in the LRPT data stream.

Frequencies[edit]

  • Meteor-M N2-2 137.1 MHzMegaHertz (MHz) 10^6 Hz - 137.9125 MHzMegaHertz (MHz) 10^6 Hz (No LRPT broadcast, but the HRPT broadcast is working)
  • Meteor-M N2-3 137.1 MHzMegaHertz (MHz) 10^6 Hz - 137.9125 MHzMegaHertz (MHz) 10^6 Hz (Active, antenna not deployed correctly)
  • Meteor-M N2-4 137.9 MHzMegaHertz (MHz) 10^6 Hz (137.1 MHzMegaHertz (MHz) 10^6 Hz used as a backup frequency) (Active)

Decoding Tutorials[edit]

Video Examples[edit]

Additional Links[edit]

Additional Images[edit]