Graduation Project developed at Cape Peninsula University of Technology in 2004 entitled: "Satellite Communication - Weather Satellite Image Download System", a low-cost system for communicating with satellites weather, which consists of an FM receiver and a PC, enabling receiving signals propagated through space, decoding the signals and displaying the captured images of the planet and its atmosphere.

1. Department of
Electrical Engineering
Claudemir Stenico
Mr. Miles B. Jacobs

2. Weather satellites
Employed a simplified data process system
with reduced complexities, low cost
satellite image reception and analysis
facility.

3. Aims
To acquire information and receive data from
weather satellite and to obtain pictures from
available satellites orbiting South Africa, using:
• FT-847 (Yaesu)
• PC (input soundcard)
• WXSAT - WXTOIMG (program to process wav files)

4. YAESU – FT-847
144.986 = 1695 MHz (UHF)
Polar-orbiters satellites - the IF bandwidth must be wide enough to
pass the entire signal waveform.
At least 40 - 50KHz
FT-847 – 30 KHz (max)

5. Bandwidth
The bandwidth requirement is influenced by
two factors: the satellite transmitter deviation
and the Doppler effect.
NOAA platforms have a signal deviation of
about 17 KHz. Adding a Doppler shift of +-
4,5 KHz at the time of closest approach.

6. Results
From geostationary satellites
central Africa (VIS)

7. Decoding through the Software
WXSAT
Set up
interface

8. Decoding through the Software
South America (IR)
1 channel 2 channels

9. Flow signal diagram
Due to the large amount of data, the lowest
standard sampling frequency that fulfils the
Nyquist criteria the soundcard must have fixed
sampling frequency (11025 kHz)

10. Decoding aspects
Eastern Africa (VIS)
1 channel 2 channels

11. Decoder Software
Wxtoimg
Interface

12. Eclipse!!!
Meteosat operations are affected for the two eclipse periods
each year when the satellite undergoes an eclipse of the sun
by the Earth. The two periods occur at the equinoxes.
During the actual eclipse, certain satellite functions,
including earth imaging and all dissemination services are
interrupted in order to save power.

13. METEOSAT 7
An eclipse of the sun
occurs when the satellite
passes into the conical
shadow region of the
earth or of the moon.
(2004, 20 Oct).

14. Colour enhanced for the Globe

15. Southern Hemisphere
South Africa

16. The future
During ten years (2000-
2009), there will be a
transition of the present
low-resolution satellite
service called APT and
WEFAX to LRPT &
LRTI, a digital system.
Everything must still be
improved.

17. Thank you!! Questions??