ࡱ> {}~ \p Schemasoft Ba=@"`=-X>78X1Arial1,Helvetica Neue1,Helvetica Neue18Times New Roman Bold1,Helvetica Neue1, Helvetica Neue1, Helvetica Neue1[SO                + ) , *   |@@ | @ | @ | @ |@  |   |  (|@  (|   |   |  (|@  (|   |   |  |@  (|@  (|   |   |  |@ @  |@ @  (|@ @  |@ @  (|@ @  (|@ @  (|@ @  |@ @  (|@ @   |@ @   |@ @  |@@ | @ | @ | @ |@  |   |@  |   |@  |   |     , < ;=<R>n3LinkBudgetAverage - Table 1>cLinkBudgetHorizon - Table 1FLinkBudgetVerticallyAbove - TabFAverageDistanceCalculation - Ta B  Link Budget of i-INSPIRE (average) - updated 19/3/2012 ZAntenna type of Ground Station: yagi-uda all polarisation, 6 direction directional antenna2Antenna type of TubeSat: centre fed dipole antennaOrbit altitude: 310 kmjMaximum Transmission Distance: 310 km (directly ahead - look on next sheet for as far as possible version)`Note: must be decibel watts otherwise log10(noise power) etc, is in dBW and needs to be the same ParameterValueUnitCommentCertain?SourceDownlink link Budget:TubeSatTransmitter Power Output:Wpower output from the amplifier. In radio transmission, transmitter power output (TPO) is the actual amount of power (in watts) of radio frequency (RF) energy that a transmitter produces at its output.y)RadioMetrix data sheet - see tubesat infoTotal Transmission Line Losses:dBdepends on amplifier to antenna connections, power loss in lines is minimal (but calculate via I^2R). Coaxial cable losses used. 5dB per 100 ft at 400MHz. Length = approximated to 2 ftn! http://www.w4rp.com/ref/coax.html Antenna Gain:dBiTrelative to a hypothetical isotropic antenna. In electromagnetics, an antenna's power gain or simply gain is a key performance figure which combines the antenna's directivity and electrical efficiency. As a transmitting antenna, the figure describes how well the antenna converts input power into radio waves headed in a specified direction, http://www.marcspages.co.uk/tech/antgain.htmTubeSat EIRP*:dBWEIRP = P_out - L_cables + G_antenna [in dB]. Doesn t matter if P_out is taken relative to 1mW or 1W, as long as the link margin calculation and the antenna receiving gain is relative to the same value.D http://en.wikipedia.org/wiki/Equivalent_isotropically_radiated_powerDownlink Path:*TubeSat Antenna Pointing Loss:1depends on attitude of satellite, optimum is zeroS http://www.tutorialsweb.com/satcom/link-power-budget/calculation-of-link-margin.htmAntenna Polarisation Loss:hLoss (in DB) = 10*(log base 10)(cos(theta))^2; where theta is the angle between the polarisation vectors@ http://www.amsat.org/amsat/archive/amsat-bb/200101/msg01220.htmlPath Loss (time average):depends on distance (position of satellite), possibly =20*LOG10(4*PI()*(310e3)*400e6/3e8), or just: =10*LOG10(1/(4*PI()*(310e3)^2))?& http://en.wikipedia.org/wiki/Path_lossAtmospheric Loss:[see numerous link budgets. Also see dissertation page 15. 1.1 was used in many link margins link budgets** Rain losses?dB/m1depends on amount of rain the signal goes through---Ionospheric Loss:7look up scintillation losses, see numerous link margins)Isotropic Signal Level at Ground Station:sum the above up to EIRPGround Station%Ground Station Antenna Pointing Loss:Ldepends on ground station antenna tracking error, zero pointing loss assumed(need to test, also see blue presentation; http://www.antenna-theory.com/antennas/travelling/yagi3.php.Ground Station Total Transmission Line Losses:$need to test, averaging link budgetsEffective Noise Temperature:Kguess from other link budgets dissertation Ground Station Figure of Merit Gain - 10log10(T_effectivenoise)/ http://www.aticourses.com/antennas_tutorial.htm Eb/N0 method-Signal to Noise Power Spectral Density (S/No)dBHz)Signal - No [dB], No = k*T_effectivenoise3 http://en.wikipedia.org/wiki/Noise_spectral_densitySystem Data Rate:bps#assumed to be what i-INSPIRE can dospecs(Telemetry System Eb/No for the Downlink:%Eb = energy per bit = signalpower/bps" http://en.wikipedia.org/wiki/Eb/N0!System Allowed or Bit-Error-Rate:-3depends on the modulation method. Ours is FM or FSK+ http://en.wikipedia.org/wiki/Bit_error_rate Demodulator Implementation Loss:see other link budgets!Telemetry System Required Eb/N0*:Eb/No Threshold:System Link Margin: 65.1989-12 SNR method(Signal Power at Ground Station LNA Input<LNA = low noise amp, so equals signal + antgain - linelosses%Ground Station Receiver Bandwidth (B)Hz$G.S. Receiver Noise Power (Pn = kTB) prob correct,Signal-to-Noise Power Ratio at G.S. Receiver5signal p<^ower at LNA imput - receiver noise power [dB]%Analog or Digital System Required S/NSystem Link Margin)basically everything is explicitly in dBWUplink Link Budget:Ground Station:(Ground Station Transmitter Power Output: (see downlink description above)Ground Station EIRP: Uplink Path:Antenna Polarisation Losses:Atmospheric Losses:Ionospheric Losses: Rain Losses:%Isotropic Signal Level at Spacecraft:Antenna Pointing Loss:Figure of Merit:dB/KSystem Desired Data Rate:Command System Eb/No:System Allowed Bit-Error-Rate:?/ * EIRPEquivalent isotropically radiated power ]* Eb/N0=CNR*B/F,CNR:carrier-to-noise ratio;f is the channel data rate,B is channel bandwidth + X to also provide independent measurement( typical value from other link budgetsB  Link Budget of i-INSPIRE (horizon) - updated 19/3/2012 F  Link Budget of i-INSPIRE (vert. above) - updated 19/3/2012 )Finding the average transmission distancetheta between 0 and max angle max angle is: in degrees this isso we start atTHETAD AVERAGE [km]Z XR  *B4"#%J'@J)E+,G.12G   dMbP?_*+%U "d??} } } ,} Z} ,#} B} R}  0@`TTTTTQ' ' ' @  @ @@@@@@(@''''&@@,@'.@'2@'   !""""#$  !""""#$% &''''()* + + + + + + ,  - - - - - - .  * * * * * * - / -? / - - - * 0 * 0 1 1 1 - / -@ / - - -* 0.*J( D AD D  0 * * * 2 ------ *! 0"* 0 *# * *$- /%- / -& - -'* 0(I*ʧ #b3Ah_0A׷AAA 0 *) * **- /+- / -, - -- *. 0/* 00 *1 * *2- /3- / -4 - --* 05#*+b %B 0 *6 * *- 27------ *! 08* 0 *9 * *2- /-(@ / -: - -;* 0<* 0 *= * *-- />-@@ /? -@ - -A *B 0C(*)-D DA 0 *D * *E 2F2-/---* 0G2*MI@D n@ 0;DA 0H *I * *J- /K-@ /L -M - -N !@!%@"'#'$'%'&''@@(@@)@@*@@+@@,@@-'.@/'0'1'2'3@4'5'6@7,@8@9@:';@<'=@>'?' * 0O? *(+4@)D DA n@ 0;DA 0 *P * *Q!- !/R!3h㈵> !-S !-T !- !-U "*V "0W"* "0 "*X "* "*-#- #/Y#-(@ #/ #-X #- #--$* $0Z$*(@ $0 $*X $* $*-%- %/[!%-P7W!@ D D$ %/ %-\ %- %-2 &.]&.&*&0&*&*&*'2 '/^#'-+ġa %B '/ '-_ '- '--(. 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