MSG: The next generation...

On august 29 2002 the first of a new generation weathersatellites was launced: Meteosat Second Generation. Eventually this generation will replace the old Meteosat satellites, designed 25 years ago.

The data transmitted by MSG satellites differs a lot compared to the current first generation Meteosats:


First gen. (MET7 and lower)Second gen. (MET 8 and higher)
Data formatAPT (analog), HRILRIT, HRIT
Data related to frameFixed: 4 or 8 frames/lineNo relation: packets
Bits codedNoYes; Viterbi
ScrambledNoYes
Error correctionNoYes; Reed Solomon
CompressionNoYes; JPEG
EncryptionpartlyLRIT: partly?
HRIT: ?

Because of the fixed data/frame relation, the straight-forward bit transmission and the absence of compression the HRI format is very simple to handle. It is even possible to plot the picture by means of a "picture drum", without the use of a computer.

This simplicity has also its draw-backs:

MSG transmits its data in a much more complex /sophisticated way, giving the following advantages:

Just like the old Meteosat sends its data in 2 flavours (APT, HRI) MSG has also 2 flavours: LRIT and HRIT. These 2 digital formats are very similar. Difference is that HRIT has 10 bits per pixel (LRIT: 8) and HRIT is lossless compressed (LRIT: lossy JPEG).
Also, the modulation is different: BPSK for LRIT, QPSK for HRIT. Which means that the receivers for both formats are different.

Because of a burned-out transmitter in MSG1 all data is now distributed using the Hotbird satellite. Advantage for amateurs is that the equipment needed to receive MSG is very easy to get:

For the translation software I did make 'xrit2pic'. It is free available, see further on my website.



Trouble-shooting Eumetcast

Summary.

Signal path:
  1. Receiver
  2. Tellicast
  3. EKU
  4. ==> File
  5. Postprocessing: xrit2pic, weview etc.

Receiver.

Data is filtered by means of PID's One pid Must always be present: The other PID's are optional:

Tellicast: Who is afraid of red, yellow and purple?

Note: following info may not be complete, or even 100% correct.


A running tellicast will show a coloured T in your Icon bar. It can show 3 different colours:

  1. Yellow: Tellicast is trying to establish a connecion. It stays yellow if no connection can be made, e.g. because:
    • firewall blocks connection
    • nothing received
    • wrong satellite received
    • PID 100 not enabled
    • There is no ethernet route between receiver and Tellicast. See below
  2. Purple: OK, PID 100 Eumetcast data received.
  3. Red:
    • interface_address wrong (recv.ini; 0.0.0.0 is "always OK")
    • Connection lost, i.e., there was a connection (purple T) but connection was lost because of one of the reasons mentioned near Yellow T.

    Note that if nothing changes the T stays red, but if you restart Tellicast the T becomes yellow! (Except if interface_address is wrong.) So the only difference between yellow and red is the past.

    Note: Following items do NOT influence your T-colour:

    • missing/malfunction EKU
    • wrong user address
    • wrong password
Note IP connection: This depends on what type of receiver you use.

EKU

Make sure that the EKU you use belongs to the user_name and user_key in your recv.ini. If you don't have a key the define:
[recipient]
user_name=eumetcastuser
user_key=9Ecast3004us
You will then only receive the 'free' data.

Postprocessing.


Deactivate start tellicast at boot (Windows).

Navigate using e.g. 'This computer' to: At this place you should see an icon 'pink T', called 'BisinessTV-IP Now Tellicast wil not start anymore a boot-time. By moving the link back to the original place you can restore the auto-start-at-boot.