Supersonics, RF Harmonics, Digital Electronics and Teddy Bears A - PowerPoint PPT Presentation

Supersonics, RF Harmonics, Digital Electronics and Teddy Bears A Cambridge University Wireless Society & Caius Engineering Society talk by CU Spaceflight Henry Hallam M Ø HMH Ed Moore M Ø TEK Fergus Noble M Ø NBL Thursday 5 March 7.00pm Bateman Auditorium, Caius College CUWS Free entry – All welcome G6UW

Assumption: Reaching space is expensive and difficult Is it?

3 programmes

Nova

Nova Latex Balloon Explosive link thing Parachute Payload Antenna Banana

Flight Computer Microcontroller (ARM7) USB Memory Card

Flight Computer (reverse) GSM Modem GPS

How do we know where it is? GPS Receiver Flight Computer Radio Transmitter ? Us on the ground

Digital Communications Phase-shift keying (PSK) Frequency-shift keying (FSK)

Decoding FSK e.g. Radio Teletype (RTTY)

Decoding FSK

Decoding FSK

Can we do any better?

Multiple Frequency-shift keying (MFSK) e.g. DominoEX - uses 18 different frequencies

Getting Involved Free Decoding Software - FLDIGI 434.650 MHz LSB: RTTY 50-baud 7-bit ASCII DominoEX 22 $$Badger,4528,12:23:06,52.2135,0.0964,28320,2,0,1 Callsign Seconds Time Latitude Longitude Altitude since launch more details at www.cuspaceflight.co.uk

Aurora Nova

Aurora ‘Zero Pressure’ Balloon Rocket

Long duration, Long distance 434 MHz - L.O.S, small antennas 14 / 3.5 MHz - over the horizon, long distance

DDS: Direct Digital Synthesis ~ £10 Max Clock 400MHz Max signal (Nyquist) 200MHz

Nyquist Limit 364 + 70 = 434 MHz Fundamental signal Clock Freq = 364.8 MHz Fundamental signal = 70MHz

Martlet Aurora § Nova

Martlet Main Parachute Avionics Drogue Parachute Motor

COCOM Martlet limit Altitude 60,000 ft 300,000ft Velocity 1000 kts 3000 kts Acceleration 4 G 50 G

Thermal Noise Floor

Acquisition

100Hz Naviagtion Output data

Questions?

Questions?

Questions?

Questions?

Questions?

Questions?