For long distance WSPR links where the transmission is at 37 dBm, the mean received SNR is typically between -14 dB and -22 dB and the standard deviation SNR is between 4 dB and 5 dB. Some antenna are omni-directional, others are directional from a low to a high degree.īetween 7th March 2014 00:00 UTC and 8th March 2014 02:00 UTC there were 297,985 WSPR spots covering all bands, all distances (from the same Maidenhead grid cell to the other side of the world at a distance of 19,704 km) and all transmission power levels (0 dBm to 60 dBm). Typical Rx antenna between 30 MHz to 80 MHz are dipole at 10 meters above ground level. Typical Tx antenna between 30 MHz to 80 MHz are 1/4 wave vertical above good ground. Typical Tx and Rx antennas between 10 MHz to 20 MHz are 3-element Yagi at 10 meters above ground level. WSPR transmissions range from low frequency up to 144 MHz, but on 7th March 2014 78% were in either the 10 MHz, 14 MHz or 28 MHz bands. A lot depends on the location of the antenna, proximity of metal fences, metal fuel tanks, electricity pylons, trees, buildings, highways, hills, mountains, ocean, airports, etc. Many radio stations experiment with different configurations of antenna and make changes in order to improve transmission and reception. Many radio stations use a number of different types of antenna and switch between them depending on what they are trying to achieve. There is a large variety of antenna used. The type of antenna used is not included in the WSPRnet database, but most stations publish their antenna information. (The paper has been updated on 14th April 2021 to correct an error in the numbering of the thanks for your excellent question. Neither system is perfect for this task, but together they can give a good result. However, together the two systems can be used to detect, identify and localise MH370 during its flight path into the Southern Indian Ocean (SIO). The SATCOM on MH370 was an Inmarsat satellite communication system.īoth systems were designed for another purpose other than the detection, identification and localisation of aircraft. Inmarsat’s network provides communications services to ships, aircraft and remote regions where there is no reliable terrestrial network. It provides telephone and data services to users worldwide, via portable or mobile terminals which communicate with ground stations through fourteen geostationary telecommunications satellites. Inmarsat is a British satellite telecommunications company, offering global mobile services. WSPR was designed to test radio signal propagation. WSPR uses frequency-shift keying and forward error correction to reliably send data tens of thousands of miles with just a few milliwatts of power. WSPR is a digital radio communication protocol designed for weak signal transmission. The Weak Signal Propagation Report (WSPR) is based on a protocol invented by Joe Taylor.
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