There are several weather satellites which are in a polar orbit. That means they are going from pole to pole and the earth is moving below them and this way they can visit the complete surface of the earth within a few days. And the best thing is they are sending unencrypted data back to earth in form of pictures from the surface.
The NOAA satellites are the most famous ones, but there are others like MetOp and FengYun. The NOAA satellites are using the APT (Automatic Picture Transmission) in the 2m band and HRPT (High Resolution Picture Transmission) at 1,7GHz. The MetOP and FengYun satellites use only HRPT at 1.7GHz. Check out the Frequencies page for a comprehensive list of the used frequencies.
To receive the data send by the satellites you need only a RTL-SDR stick and a helix antenna. The HRPT can be a bit difficult as 1.7GHz is near the upper limit of the RTL-SDR stick, but it should work. The helix antenna is easy to build.
Link list:
https://medium.com/swlh/decoding-noaa-satellite-images-using-50-lines-of-code-3c5d1d0a08da
https://www.rtl-sdr.com/gr-hrpt-gnu-radio-hrpt-decoder-blocks-for-noaa-meteor-metop-and-fengyun-3-weather-satellites/
https://www.rtl-sdr.com/improving-hrpt-reception-free-hrpt-decoder/
https://www.rtl-sdr.com/receiving-noaa-19-hrpt-with-a-hackrf-lna4all-and-cooking-pot-antenna/
https://github.com/altillimity/HRPT-Decoder
http://jcoppens.com/ant/qfh/calc.de.php – Rechner für QFH Antennen
https://en.wikipedia.org/wiki/High-resolution_picture_transmission
https://en.wikipedia.org/wiki/Low-rate_picture_transmission
https://www.eumetsat.int/media/43321 – HRPT specification
https://github.com/Xerbo/LeanHRPT-Decode – HRPT Decoder software
https://sgcderek.github.io/posts/beginner-hrpt-guide/#11-below-17-ghz - Guide for HRPT
https://usradioguy.com/goes-satellite-imagery-reception/
https://www.satdump.org/
https://github.com/SatDump/SatDump
StratoSat TK1 https://www.nanosats.eu/sat/stratosat-tk1 435.870MHz
POCSAG is the protocol used for the pager networks.
There are several commercial providers and with DAPNET exists a network for ham radio.
DAPNET https://hampager.de/
The used frequency for DAPNET in Germany is 439.9875 MHz (https://hampager.de/dokuwiki/doku.php?id=dapnetfrq).
Easiest way to use DAPNET is to host a transmitter with a MMDVM HotSpot Board (https://github.com/juribeparada/MMDVM_HS) with PI-Star (http://www.pistar.uk/) on a Raspberry Pi Zero.
If no pager hardware is available a rtl sdr can be used.
Use GQRX as the receiver and forward the POCSAG signal to multimon-ng:
nc -l -u -p 7355 | sox -t raw -esigned-integer -b 16 -r 48000 - -esigned-integer -b 16 -r 22050 -t raw - | multimon-ng -t raw -a POCSAG512 -a POCSAG1200 -a POCSAG2400 -f alpha -
This a version which should work without GQRX but is not tested and frequency has to be adjusted to Germany (https://lokcon.me/2019/06/18/rtl-sdr-pocsag)
rtl_fm -M fm -f 439.9875M -s 22050 -g 100 -l 310 | multimon-ng -t raw -a POCSAG512 -a POCSAG1200 -a POCSAG2400 /dev/stdin
For test purposes you can send a POCSAG message locally from the pi-star system:
sudo RemoteCommand page “”
(https://forum.pistar.uk/viewtopic.php?t=746)
https://en.wikipedia.org/wiki/POCSAG
https://de.wikipedia.org/wiki/Radio-paging_code_No._1
https://www.qsl.net/db0avh/code.html - Nachrichtenaufbau von POCSAG
http://www.sxlist.com/techref/pager/pocsag.html - Nachrichtenaufbau von POCSAG
https://www.thingiverse.com/thing:2497461 Helix Antenna for 5.8 GHz
https://www.thingiverse.com/thing:858112 Helix Antenna for 5.8 GHz
https://www.thingiverse.com/thing:367500 Helix Antenna for 5.8 GHz
https://www.thingiverse.com/thing:4720600 Helix Antenna for 1.7 GHz https://github.com/sgcderek/dsgc-helix-scaffold
https://sgcderek.github.io/tools/ATA.html Calculator for asymmetric turmstile antennas
144.8 MHz APRS Frequenz in Europa
432.5 MHz APRS Frequenz in Europa
439.9875 MHz DAPNET (POCSAG) Frequenz
Relais
Relais Stuttgart 70cm 438.56250 (DB0LBG) at Katharinenlinde, Sightseeing Tower, DE. – https://www.repeaterbook.com/row_repeaters/details.php?state_id=DE&ID=9634
Relais Hannover 70cm DB0FUS 439,200 MHz – https://z08.vfdb.org/relaisstellen/db0fus/
Relais Hannover 70cm DB0TVH 439.2375 MHz – Bredero-Hochhaus – http://www.db0tvh.de/
438,337,5 MHz DMR+-Relais DB0LBG am Kathrinen-Linden-Turm
WSPR frequencies
http://wsprnet.org/drupal/node/218
Satelitte frequencies
Meteor-M2
ISS
NOAA-18
NOAA-15
NOAA-19
MetOp-A
AHRPT: 1707mhz
MetOp-B
AHRPT: 1701.3mhz
FengYun-3B
CHRPT: 1704.5mhz
FengYun-3C
CHRPT: 1698mhz
StratoSat TK1
https://www.nanosats.eu/sat/stratosat-tk1 435.870MHz
137,563200
LSB USB
Hannover Information Wetter, Zeit
440,9386 MhZ
Packet radio
Hannover
439.862 mhz
https://4noobs.de/viewtopic.php?f=29&t=87
https://entropia.de/GPN15:Radioastronomie:_Mit_selbstgebautem_Equipment_die_Milchstra%C3%9Fe_vermessen
https://www.sciencefriday.com/articles/build-your-own-radio-telescope-to-listen-to-meteors/
http://www.radio-astronomy.org/
https://hackaday.io/project/27582-radiotelescope-interferometer-imfr11ghz
http://opensourceradiotelescopes.org/
http://blog.svenbrauch.de/2015/04/26/21cm-hydrogen-line-telescope-version-2/
http://blog.svenbrauch.de/tag/radio-telescope/
https://www.hackster.io/mariocannistra/radio-astronomy-with-rtl-sdr-rpi-and-amazon-aws-iot-45b617
https://github.com/mariocannistra
https://www.rtl-sdr.com/pictor-an-open-source-low-cost-radio-telescope-based-on-rtl-sdr/
http://www.ccera.ca/
https://github.com/byggemandboesen/H-line-software
https://jgeheniau.wixsite.com/radio-astronomy
SDR
http://gqrx.dk/ – SDR Software
Digitale Betriebsarten
http://physics.princeton.edu/pulsar/K1JT/index.html – WSJT Homepage Software für WSPR und andere Betriebsarten
Satelittenfunk
http://gpredict.oz9aec.net/ – gpredict
Digital Modes
https://freedv.org/ - A Digital Voice mode for HF radio
http://www.qsl.net/hz1jw/pythonprop
http://www.qsl.net/hz1jw/index.html
https://radio.linux.org.au/?sectpat=All&ordpat=title
SSTV
http://users.telenet.be/on4qz/index.html
DAB+
https://www.welle.io/
CW
https://github.com/rshk/pycwgen – Python CW generator
DMR
https://github.com/szechyjs/dsd
RDS
https://github.com/windytan/redsea – RDS decoder software
https://www.windytan.com/2015/02/receiving-rds-with-rtl-sdr.html – Receive rds with redsea
https://www.public-software-group.org/radioircd
https://www.bastibl.net/projects/
https://www.bastibl.net/gqrx-for-digital-signals/
https://github.com/ChristopheJacquet/Pydemod
https://github.com/artlav/meteor_decoder
https://www.irif.fr/~jch/software/babel/ – meshed routing protocol
https://github.com/fingon/pybabel/ – python babel Implementierung
https://www.hamspirit.de/12299/selbstorganisierende-ad-hoc-netze-mit-babeld/
https://www.public-software-group.org/pktfec-tnc – TNC software
https://www.public-software-group.org/radioircd – radioircd irc server
https://github.com/la5nta/pat
https://github.com/craigerl/aprsd
https://github.com/Xerbo/LeanHRPT-Decode
http://www.hfsignals.com/ – BITX Transceiver
http://www.phonestack.com/farhan/
https://github.com/afarhan
https://unsigned.io/micromodem/
https://twitter.com/ibelings/status/1039672385434267648?s=21
https://github.com/loxodes/vna
https://github.com/ttrftech/NanoVNA
https://github.com/etherkit/LA0W5
http://ardutrx.generationmake.de/
https://github.com/phl0
https://github.com/DD5HT
https://github.com/dh1tw
https://github.com/VE3WZW
https://github.com/juribeparada
https://github.com/cintema
https://github.com/m1geo
https://github.com/ko7m
https://github.com/freedv
https://github.com/dh1tw/pyhamtools
https://github.com/hjd1964
https://github.com/loxodes
https://github.com/LongHairedHacker
https://github.com/F5OEO
https://gogs.zenerdio.de/sebastian
https://github.com/jmharvey1
https://github.com/0xCoto/PICTOR
https://github.com/afarhan
https://github.com/f4exb
https://github.com/poes-weather
https://github.com/altillimity
https://github.com/Supermagnum/Pirotator
https://github.com/r4d10n/mmdvm-sdr
Generell
https://ham.stackexchange.com/
Speziell
https://www.repeaterbook.com/ - Database of relais stations worldwide
http://physics.princeton.edu/pulsar/K1JT/index.html - Weak signal communication
https://www.facebook.com/Arduino-ARM-Ham-Radio-Projects-1726519644283112/
http://ko7m.blogspot.com/
http://diycrap.blogspot.com
http://www.vk2zay.net/ - Alan’s Lab - some amateur radio projects
http://www.m0nka.co.uk - mcHF QRP transceiver - Small and inexpensive homebrew HF radio
http://n6qw.blogspot.com - The N6QW blog collects and shares bits of information on one ham’s homebrewing activities
http://www.rowetel.com/?page_id=452 - Codec 2 - A free speech codec
https://www.tu-chemnitz.de/urz/stammtisch/rsrc/handout_Oktober2016.pdf - Open Source für Funkamateure
https://hackaday.com/2015/02/02/get-serious-with-amateur-radio-design-build-a-single-sideband-transceiver-from-scratch-part-1/
https://hackaday.com/2015/03/04/get-serious-with-amateur-radio-design-build-a-single-sideband-transceiver-from-scratch-part-2/
https://hackaday.com/2018/08/17/radio-antenna-mismatching-vswr-explained/
http://www.afug-info.de/Schaltungen-Eigenbau/Wouxun/ – Kabelbelegung Baofeng
https://4.bp.blogspot.com/-9suMCd65qtg/VpvhXJSHB0I/AAAAAAAANvs/xJVZmbVveoM/s1600/baofetent.jpg – Kabelbelegung Baofeng 2
http://www.miklor.com/COM/UV_Technical.php – Kabelbelegung Baofeng 3
https://ham.stackexchange.com/questions/1891/whats-the-pinout-for-kenwood-2-5mm-trs-3-5-mm-trs-connector – Headset Pinbelegung Baofeng
http://www.sarcnet.org/projects/project_rotator.html – Antennensteuerung
https://www.dk0tu.de/users/DL5BBN/Python_Amateur_Radio_Programs/
https://hackaday.io/project/161556-tiny-radio-telescope
https://hackaday.io/project/161503-vhffm-receiver
https://hamprojects.wordpress.com/2015/06/29/vhf-beacon-and-aprs-tracker-english-version/
https://hamprojects.wordpress.com/
https://amsat-uk.org/beginners/how-to-hear-the-iss/
http://jcoppens.com/ant/qfh/calc.de.php – Rechner für QFH Antennen
http://wiki.oevsv.at/index.php?title=Interessensgruppen
https://mode-s.org/
https://media.ccc.de/v/3CGHAH
http://www.rish.kyoto-u.ac.jp/digitalbeacon/information/Building_QFH_Antenna_Guide.pdf – QFH Antenna building guide
https://windytan.github.io/slowrx/
http://www.linux-ax25.org/wiki/Main_Page
http://www.windytan.com/
https://www.windytan.com/2015/02/receiving-rds-with-rtl-sdr.html
https://github.com/DecentralizedAmateurPagingNetwork – DAPNET ein Hampager Netzwerk
https://www.qsl.net/5/5b4az//
http://www.centerforspace.com/
https://www.rtl-sdr.com/creating-a-standalone-wspr-receiver-with-an-rtl-sdr-v3-and-raspberry-pi-3/
http://rfsparkling.com/blog/2018/12/21/making-a-standalone-wspr-receiver-using-raspberry-pi-and-rtl-sdr-v3-dongle-with-rtlsdr-wsprd-software/
https://wiki.oevsv.at/index.php?title=Links
https://aa7ee.wordpress.com/
https://aa7ee.wordpress.com/2016/09/09/a-scratch-build-of-n6kr-and-wilderness-radios-sst-for-20m/
http://www.amateur-funk.de/Dateien/2m.htm
http://www.dk3wn.info/satellites.shtml
https://github.com/F5OEO/rpitx
https://hackaday.com/2016/06/02/the-minima-is-an-all-band-hf-transceiver-for-under-100/
https://github.com/afarhan/radiono
https://hackaday.com/2019/01/22/understanding-modulated-rf-with-w2aew/
https://www.sigidwiki.com/wiki/Signal_Identification_Guide
https://www.amsat.org/amsat/articles/kd2bd/9k6modem/schematics.html
http://www.f6fbb.org/
https://sites.google.com/site/g3xbmqrp3/vuhf/fredbox
https://www.qsl.net/va3iul/144MHz%20All%20Mode%20Transceiver/2m_allmode.html
http://f6feo.homebuilder.free.fr/transceiver_PICARDY.html
https://github.com/generationmake/ArduTrx
http://www.nordlink.org/
https://gogs.zenerdio.de/sebastian/ark-lna
https://buildyourownantenna.blogspot.com/2014/07/double-biquad-antenna-calculator.html
https://github.com/aerospaceresearch/DirectDemod
http://www.antennamagus.com/blog/216/making-your-own-bi-quad-wi-fi-antenna
https://hackaday.io/project/164092-npr-new-packet-radio
http://www.hamqsl.com/solar.html – Solar Data Banners & Widgets
https://hackaday.io/project/164092-npr-new-packet-radio
http://funknetzplanung.com/frequenzplan.php
http://www.dd1us.de/
https://www.arig-mn.org/ – Amateurfunk Relaisinteressengemeinschaft Mittlerer-Neckar e.V.
https://github.com/altillimity/SatDump
https://radiohacks.de
https://m17project.org/
https://www.satblog.info/
https://dl2man.de
https://sgcderek.github.io/index.html