AAE 450 Spring 2008 Justin M. Rhodes Avionics – Telecommunications Analysis Code Integration and Automation Webmaster Sample Design and Failure Analysis Avionics. Don’t leave home without us.

AAE 450 Spring 2008 Telecom Design: Sample Case Model: LG-CA-DA-DT  Power Distribution: Wiring m of wiring runs kg mass - $ 200 material cost - $ 7,172 installation cost  Assumptions –Main avionics bay located in second stage –Payload communications system will be utilized Avionics 1 ItemValueUnits frequency401MHz transmitter power5Watts transmit antenna beamwidth60deg transmit antenna diameter0.87m equiv isotropic radiated power12.3DBW propagation path length5000km receive antenna diameter10m receive antenna beamwidth5.24deg data rate9600bps signal to noise ratio50.82dB carrier to noise density ratio90.64dB-Hz bit error rate implementation loss-2dB final margin39.20dB Simplified Link Budget Analysis

AAE 450 Spring 2008 Telecom: Failure Analysis Avionics 2 Sources of Failure Telecom Equipment Radio Transmitter Receiver Antenna Internal Data Handling Data processing Data wiring External Sources Doppler ShiftPower Supply Orientation Misalignment Reliability Factors For a low complexity system with redundancy 1 : Part Class Reliability Class B: Class S: Assumptions - Simple system - Low radiation dose - Reliability based on a five year mission plan 1 Wertz, 404.

AAE 450 Spring 2008 Telecom Sample: Doppler Shift Effect Frequency Shift at Vehicle Delta V for 401 MHz Frequency Avionics 3 f = transmitted frequency v = velocity at which the vehicle is travelling away from the ground station c = speed of light λ = wavelength of transmitted wave Calculating Doppler Shift

AAE 450 Spring 2008 Telecom Sample: Bit Rate Analysis Data Rate Analysis for 401 MHz Frequency Avionics 4

AAE 450 Spring 2008 Telecom Sample: Path Length Analysis Path Length versus Final Link Margin for 401 MHz Frequency Avionics 5 Note: Atmospheric conditions were not factored into this analysis. Signal path is determined by atmospheric conditions the signal travels through and will limit the maximum range to the target.

AAE 450 Spring 2008 Telecom Sample: Power Distribution Cost Primary Contractor: Aircraft Electrician Avionics 6 Median Salary 1 $40, Work Days per Year240 Income Per Day$ Income Per Hour$21.35 Billing Rate Per Hour$32.02 At four weeks of billable work Installation Cost:$7, Salary data from 2 Cost from TexWire, Wire Size Cost per meter 2 22 gauge$ gauge$3.02 MIL-W-16878/4 Electrical Wiring

AAE 450 Spring 2008 References 1.Fortescue, Peter and John Stark. Spacecraft Systems Engineering, Wiley, New York, NY, Wertz, James R. and Wiley J. Larson. Space Mission Analysis and Design, Microcosm Press, Torrence, CA, TexWire Wire & Cable. Avionics 7