π‘ himawari-rx - HimawariCast Downlink Processor
himawari-rx is a decoder for receiving images from geostationary weather satellite Himawari-8 (140.7ΛE) via the HimawariCast data service operated by Japan Meteorological Agency. HimawariCast is a DVB-S2 signal transmitted from JCSAT-2B (154Β°E) on its global C-band beam. It can be received with a 2.4m satellite dish and a standard C-band LNB. It may be possible to use a smaller dish however this has not been verified.
himawari-rx receives UDP datagrams over a network connection and outputs decoded image files to disk. The UDP datagrams can come from either a DVB-S2 receiver card such as a TBS5520SE or a satellite IP receiver such as the Novra S300D. A Software Defined Radio solution using GNU Radio is currently under development.
Getting Started
A (work in progress) guide for setting up the hardware and software components of a HimawariCast receiver is available on my site.
In the meantime here is a quick overview of the required setup:
HimawariCast is a C-band DVB-S2 downlink on geostationary communication satellite JCSAT-2B at 154Β°E. The downlink frequency is 4148 MHz with a symbol rate of 2586 ksps and horizontal polarisation. On a standard 5150 MHz LO C-band LNB it has an IF of 1002 MHz.
A standard DVB-S2 receiver card/box such as the TBS6902 (PCIe) or TBS5520SE (USB) can receive this downlink either using Windows or Linux. The downlink carries multicast UDP packets which are wrapped in DVB-MPE and need to be unwrapped with software such as TSDuck, the TBS IP Tool or TSReader.
For TSDuck, the following command should work in most cases.
tsp -I dvb --adapter 0 --delivery-system "DVB-S2" --lnb "5150000000" --frequency 4148000000 --modulation QPSK --symbol-rate 2586148 --fec-inner "3/5" --roll-off 0.2 --polarity "horizontal" -P mpe --pid 0x03E9 --udp-forward --log -O drop
For TSReader, use File -> IP/DVB Mode and select PID 0x03E9 (1001), then right click on UDP: 239.0.0.1 in the PID list and select Retransmit UDP payload.
To install himawari-rx, download the himawari-rx.zip from the latest release and extract it to a new folder. Next, install the required Python packages with pip install -r requirements.txt. Finally, run himawari-rx with python himawari-rx.py.
himawari-rx will begin decoding images once UDP packets from the downlink are being transmitted onto the local network using TSDuck, the TBS IP Tool or TSReader.
Imaging Bands
Himawari-8 is capable of capturing Earth in 16 different wavelengths of light, 14 of which are transmitted via the HimawariCast service.
List of options
rx section
| Setting | Description | Options | Default |
|---|---|---|---|
path |
Root output path for received files | Absolute or relative file path | "received" |
combine |
Save all images in a single directory (XRIT2PIC compatibility) | true or false |
false |
format |
File type to output | bz2: Compressed xRIT filesxrit: LRIT/HRIT files |
xrit |
ignored |
List of channels (bands) to ignore (e.g. "B09", "IR2") |
Table of available bands | none |
udp section
These two options generally do not need to be changed.
| Setting | Description | Options | Default |
|---|---|---|---|
ip |
Multicast IP address of DVB-S2 receiver | 224.0.0.0 - 239.255.255.255 |
239.0.0.1 |
port |
UDP output port of DVB-S2 receiver | Any UDP port number | 8001 |
Acknowledgments
- @yanderen2 - Software testing and TS recordings
- tcjj3 - Software testing and scripting
- John Bell - Software testing and TS recordings
- @Apsattv - TS recordings