1. Satellite Technology n Assoc. Prof Dr Syed Idris Syed Hassan n School of Electrical and Electronic Eng n Universiti Sains Malaysia n Seri Iskandar, 31750 Perak

2. Concept Transponder Earth station (site A) Earth station(site B) IRRADIUM downlink uplink downlink uplink

3. Applications n Communication (truncking call) n Teleconference n Telemedicine n TV Broadcasting n Data communication n Telemetry(TEC, remote sensing etc) n Weather telecast n Navigation n GPS n Security/Calamity monitoring n Standard Time n military

4. Type of Satellites n LEO -Low Earth orbital 100-16,000Km (90min to 12hrs orbiting the earth) n MEO - Medium Earth Orbital 16,000- 36,000 Km (12 - 24 hrs orbiting the earth) n GEO - Geosynchronous Earth Orbital - 36,000 Km ( The satellite appears to be stationary over one point on earth)

5. Look angle (Elevation) El

6. continue n Le = Earth station Latitude n le = Earth station longitude n Ls = Satellite latitude ( = 0 for GEO) n ls = Satellite longitude n rs = Satellite orbital radius ( ~ 36,000 km for GEO) n re = earth radius = 6370 km For GEO satellite

7. Looking angle(azimuth) n Consider for GEO only N S ES Sat E W 

8. continue n If Earth station is in the North Latitude, the azimuth will be as follow (refer to N) the azimuth will be as follow (refer to N)

9. continue n If the Earth station is in the South latitude, the azimuth will be (refer to N)

10. Example

11. Link budget Noise Power Budget for 54 MHz channel Boltzmann’s Constant= - 228.6 dBW/K/Hz Receiving system noise temp.= 28.5 dBK Receiving system noise temp.= 28.5 dBK Ku- Band ‘s channel bandwidth= 77.3 dB Ku- Band ‘s channel bandwidth= 77.3 dB Receiving noise level - 122.8 dB For C/N about 10 dB to allow rain and other fading the signal level should be -112.8 dB For C/N about 10 dB to allow rain and other fading the signal level should be -112.8 dB

12. continue

13. continue In decibel

14. Continue n Parabolic antenna diameter

15. Continue n MEASAT

16. continue n JCSAT

17. continue n Superbird C

18. Teleconference System Teleconference System LNA/HPATransceiver QPSK mod & demod CODEC 1.536Mbps TVmonitor IDU ODU

19. Data communication LNA/HPATransceiver QPSK mod & demod 1.536Mbps PC Router&Transciever IDUODU

20. Other factors need to consider n Antenna n Rain attenuation n Beam Footprint n Mismatch losses n Misalignment n Scintillation ~for low elevation n troposphere/atmosphere n Bit error rate

28. Rain attenuation 1% 0.1% 0.01% % of time exceedance 20406080100 mm/hr rain rate

29. Continue n For TV and broadcasting usually the reliability is not very critical, so 99% is okay and this equivalent to 1% of exceedance of time n For data other digital com the reliability of 99.99% is probably chosen and this is equivalent to 0.01% of exceedance of time.

30. continue For 99.99% reliability, the attenuation is calculated as where a and b are constants relied on frequency R 0.01 rain rate at 0.01% of exceedance of time L path is slant path where signal passed the rain

31. Slant path L path Rainheight~3km