Distance Loss- KU Band Dish Size Calculation....
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19-11-2014, 09:19 PM
(This post was last modified: 19-11-2014 09:59 PM by SENTHIL KUMAR.)
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Distance Loss- KU Band Dish Size Calculation....
All the telecommunication satellites are in the orbit above 36000 Km from earth .(Approximately)
It delivers signal nearly 225 dB at the satellite end. But due to distance from the centre of the foot print , the signal power reduced. If you are in the foot print area , then easily calculate the size of dish by satbeam. But you are in the out of coverage area, it is not easy to calculate dish size. All the values are approximately. Example : Yahsat 1A @ 52.5 E. In pakistan the foot print is easily available. So we calculate the dish size with satbeam. [IMG]Guests cannot see images and links in the messages. Please register to forum by clicking Register Here to see images.[/IMG] OR Login to view. But in my area ( Thiruvarur ) is in out of coverage area. [IMG]Guests cannot see images and links in the messages. Please register to forum by clicking Register Here to see images.[/IMG] OR Login to view. So we didnot calculate the dish size with satbeam. CALCULATION. 225 - (36.6 + 20 (LOG (FREQUENCY * DISTANCE)) FREQUENCY - 11958 (Eg) DISTANCE - 2793 km. ( Oman to Thiruvarur ) ( from centre of Footprint to Thiruvarur) [IMG]Guests cannot see images and links in the messages. Please register to forum by clicking Register Here to see images.[/IMG] OR Login to view. (FREQUENCY * DISTANCE) = 11958*2793 = 33398694. LOG (FREQUENCY * DISTANCE) = 7.523 [IMG]Guests cannot see images and links in the messages. Please register to forum by clicking Register Here to see images.[/IMG] OR Login to view. (36.6 + 20 (LOG (FREQUENCY * DISTANCE)) = 36.6 + 20 (7.523) = 187.06 225 - (36.6 + 20 (LOG (FREQUENCY * DISTANCE)) = 225 -187.06 = 37.9 dB. So the value of signal in Thiruvarur - 37.9 dB. So , we required ku band dish size is = 6 feet ( 180 cm) |
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20-11-2014, 08:25 AM
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RE: Distance Loss- KU Band Dish Size Calculation....
If anything doubt in calculation please ask in the thread.
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20-11-2014, 10:01 AM
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RE: Distance Loss- KU Band Dish Size Calculation....
(20-11-2014 08:25 AM)SENTHIL KUMAR Wrote: Guests cannot see images and links in the messages. Please register to forum by clicking Register Here to see images.OR Login to view.excellent senthil kumar i have some doubts 1) if frequency changes db also gets changed? 2) 225 - (36.6 + 20 (LOG (FREQUENCY * DISTANCE)) in this formula what 20 refers to ? & i guess 36.6 is km distnace from sat right? thanks |
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20-11-2014, 10:08 AM
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RE: Distance Loss- KU Band Dish Size Calculation....
Dear Senthil Kumar,,
Above explanation is superb...how do i calculate dish size from my country (Colombo , SriLanka) to get YAHASAT 1A ? Pls assist... |
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20-11-2014, 10:31 AM
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RE: Distance Loss- KU Band Dish Size Calculation....
(20-11-2014 10:08 AM)Nishan-23 Wrote: Guests cannot see images and links in the messages. Please register to forum by clicking Register Here to see images.OR Login to view. First, go to google brother calculate the distance first. Then apply in the formula , you get result. I think , the same 6 feet ku band dish is enough for your place. |
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20-11-2014, 10:43 AM
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RE: Distance Loss- KU Band Dish Size Calculation....
(20-11-2014 10:01 AM)elathegreat Wrote: Guests cannot see images and links in the messages. Please register to forum by clicking Register Here to see images.OR Login to view. Thanks for your interest. 20 and 36.6 is the formula parameters. If you change the frequency , there is no big difference in result. Distance is more important. If you apply distance 5000 km , then dB value is 32.8 dB. The dish size is 10 feet. |
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20-11-2014, 10:54 AM
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RE: Distance Loss- KU Band Dish Size Calculation....
(20-11-2014 10:43 AM)SENTHIL KUMAR Wrote: Guests cannot see images and links in the messages. Please register to forum by clicking Register Here to see images.OR Login to view. thanks senthil can i get the source of the formula? |
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20-11-2014, 11:04 AM
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RE: Distance Loss- KU Band Dish Size Calculation....
(20-11-2014 10:54 AM)elathegreat Wrote: Guests cannot see images and links in the messages. Please register to forum by clicking Register Here to see images.OR Login to view. Last week, I searched on the internet for some more formula. At the time , I will catch the formula. But now I forget the site name. I re search on net, if it available I post here. I also give the link in your personal message. |
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20-11-2014, 11:16 AM
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RE: Distance Loss- KU Band Dish Size Calculation....
(20-11-2014 11:04 AM)SENTHIL KUMAR Wrote: Guests cannot see images and links in the messages. Please register to forum by clicking Register Here to see images.OR Login to view. sure thanks... waiting for your reply...... |
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20-11-2014, 01:49 PM
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RE: Distance Loss- KU Band Dish Size Calculation....
Great Work Senthil..... also give the db chart versus the dish antenna size. Also is this valid for KU as well as C band reception? and Prime Focus and offset dishes?
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