diff --git a/README b/README index 67a2e432f..e745d3ad7 100644 --- a/README +++ b/README @@ -11,70 +11,85 @@ -Copyright (C) 2001 - 2018 by Joe Taylor, K1JT. +Copyright (C) 2001 - 2019 by Joe Taylor, K1JT. -WSJT-X is a computer program designed to facilitate basic amateur -radio communication using very weak signals. The first four letters in -the program name stand for “Weak Signal communication by K1JT,” while -the suffix “-X” indicates that WSJT-X started as an extended (and -experimental) branch of the program WSJT. +WSJT-X Version 2.1 offers ten different protocols or modes: FT4, FT8, +JT4, JT9, JT65, QRA64, ISCAT, MSK144, WSPR, and Echo. The first six +are designed for making reliable QSOs under weak-signal +conditions. They use nearly identical message structure and source +encoding. JT65 and QRA64 were designed for EME (“moonbounce”) on the +VHF/UHF bands and have also proven very effective for worldwide QRP +communication on the HF bands. QRA64 has a number of advantages over +JT65, including better performance on the very weakest signals. We +imagine that over time it may replace JT65 for EME use. JT9 was +originally designed for the LF, MF, and lower HF bands. Its submode +JT9A is 2 dB more sensitive than JT65 while using less than 10% of the +bandwidth. JT4 offers a wide variety of tone spacings and has proven +highly effective for EME on microwave bands up to 24 GHz. These four +“slow” modes use one-minute timed sequences of alternating +transmission and reception, so a minimal QSO takes four to six minutes +— two or three transmissions by each station, one sending in odd UTC +minutes and the other even. FT8 is operationally similar but four +times faster (15-second T/R sequences) and less sensitive by a few +dB. FT4 is faster still (7.5 s T/R sequences) and especially well +suited for radio contesting. On the HF bands, world-wide QSOs are +possible with any of these modes using power levels of a few watts (or +even milliwatts) and compromise antennas. QSOs are possible at signal +levels 10 to 15 dB below those required for CW. -WSJT-X Version 1.6 offers five protocols or “modes”: JT4, JT9, JT65 -WSPR, and Echo. The first three are designed for making reliable QSOs -under extreme weak-signal conditions. They use nearly identical -message structure and source encoding. JT65 was designed for EME -(“moonbounce”) on the VHF/UHF bands and has also proven very effective -for worldwide QRP communication on the HF bands. JT9 is optimized for -the LF, MF, and lower HF bands. It is 2 dB more sensitive than JT65 -while using less than 10% of the bandwidth. JT4 offers a wide variety -of tone spacings and has proved very effective for EME on microwave -bands up to 24 GHz. All three of these modes use one-minute timed -sequences of alternating transmission and reception, so a minimal QSO -takes four to six minutes — two or three transmissions by each -station, one sending in odd UTC minutes and the other even. On the HF -bands, world-wide QSOs are possible using power levels of a few watts -and compromise antennas. On VHF bands and higher, QSOs are possible -(by EME and other propagation types) at signal levels 10 to 15 dB -below those required for CW. +Note that even though their T/R sequences are short, FT4 and FT8 are +classified as slow modes because their message frames are sent only +once per transmission. All fast modes in WSJT-X send their message +frames repeatedly, as many times as will fit into the Tx sequence +length. -WSPR (pronounced “whisper”) stands for Weak Signal Propagation -Reporter. The WSPR protocol was designed for probing potential -propagation paths using low-power transmissions. WSPR messages -normally carry the transmitting station’s callsign, grid locator, and -transmitter power in dBm, and they can be decoded at signal-to-noise -ratios as low as -28 dB in a 2500 Hz bandwidth. WSPR users with -internet access can automatically upload their reception reports to a -central database called {wsprnet} that provides a mapping facility, +ISCAT, MSK144, and optionally submodes JT9E-H are “fast” protocols +designed to take advantage of brief signal enhancements from ionized +meteor trails, aircraft scatter, and other types of scatter +propagation. These modes use timed sequences of 5, 10, 15, or 30 s +duration. User messages are transmitted repeatedly at high rate (up to +250 characters per second, for MSK144) to make good use of the +shortest meteor-trail reflections or “pings”. ISCAT uses free-form +messages up to 28 characters long, while MSK144 uses the same +structured messages as the slow modes and optionally an abbreviated +format with hashed callsigns. + +WSPR (pronounced “whisper”) stands for Weak Signal Propagation +Reporter. The WSPR protocol was designed for probing potential +propagation paths using low-power transmissions. WSPR messages +normally carry the transmitting station’s callsign, grid locator, and +transmitter power in dBm, and they can be decoded at signal-to-noise +ratios as low as -31 dB in a 2500 Hz bandwidth. WSPR users with +internet access can automatically upload reception reports to a +central database called WSPRnet that provides a mapping facility, archival storage, and many other features. -Echo mode allows you to detect and measure your own lunar echoes, even -if they are far below the audible threshold. +Echo mode allows you to detect and measure your own station’s echoes +from the moon, even if they are far below the audible threshold. -WSJT-X provides spectral displays for passbands up to 5 kHz, flexible -rig control for nearly all modern radios used by amateurs, and a wide -variety of special aids such as automatic Doppler tracking for EME -QSOs and Echo testing. The program runs equally well on Windows, -Macintosh, and Linux systems, and installation packages are available -for all three platforms. +WSJT-X provides spectral displays for receiver passbands as wide as 5 +kHz, flexible rig control for nearly all modern radios used by +amateurs, and a wide variety of special aids such as automatic Doppler +tracking for EME QSOs and Echo testing. The program runs equally well +on Windows, Macintosh, and Linux systems, and installation packages +are available for all three platforms. WSJT-X is an open-source project released under the GPLv3 license (See -COPYING). If you have programming or documentation skills or would -like to contribute to the project in other ways, please make your -interests known to the development team. The project’s source-code -repository can be found at https://sourceforge.net/projects/wsjt, and -most communication among the developers takes place on the email -reflector https://sourceforge.net/p/wsjt/mailman. User-level -questions and answers, and general communication among users is found -on the https://groups.yahoo.com/neo/groups/wsjtgroup/info email -reflector. +COPYING). If you have programming or documentation skills or would +like to contribute to the project in other ways, please make your +interests known to the development team. The project’s source-code +repository can be found at https://sourceforge.net/projects/wsjt, and +communication among the developers takes place on the email reflector +https://sourceforge.net/p/wsjt/mailman. User-level questions and +answers, and general communication among users is found on the +https://groups.yahoo.com/neo/groups/wsjtgroup/info email reflector. Project web site: -http://www.physics.princeton.edu/pulsar/K1JT/wsjtx.html +https://www.physics.princeton.edu/pulsar/K1JT/wsjtx.html -Project mailing list (shared with other applications from the same +Project mailing list (shared with other applications from the same team): https://groups.yahoo.com/neo/groups/wsjtgroup -