WELCOME
Atharva College of Engineering Mumbai ATHARVA COLLEGE OF ENGINEERING
Ground-Station Team Project Guide: Prof. Mrs. ArchanaChaudhari Student Members: Aniruddha Khadye Anuj Tiwari DivyaAcharya Nikhil Joshi NiraliKhandhar Saurabh Sanghai Swarnkamal Singh Parmar Viral Shah
Project Objectives • To setup an autonomous Ground Station at ACE • To retrieve TEC data operating on 437 MHz and 145 MHz • To receive Satellite Beacon on 145 MHz using VHF receiver. • To receive Satellite Telemetry data on 437Mhz using OOK UHF receiver • To log and analyze the data received • Student Outreach Program
ACE Ground Station Break Up Our Ground-Station consists of 3 main parts: • Antenna Array • Rotor Mechanism • Processing Circuit
Antenna DESIGN: • Parameters obtained from 4nec2 software. • Design was for 5 element 145 MHz Yagi-Uda antenna is shown. • 5 elements Yagi-Uda was selected for: • Better directivity • Better sensitivity • Low Bandwidth
FABRICATION: • Antenna parameters obtained from NEC aren’t always practically realisable. • Values had to be rounded up to achievable margin and the resultant design was again simulated on the software. • Best possible parameters were selected based upon their practicality as well as fulfillment of specified criterion.
Antenna Couplers & Boom
Balun • Balun is also known as Quarter Wave Transformer. • It is used for impedance matching. • Length of balun is 1\4th of wavelength. • Practically, this value has to divided by velocity factor of the medium so as to account for different velocity of signal in different medium.
Dipole Bending • Plane of polarization should be maintained while folding dipoles. • The distance between the folds of the dipoles have to be maintained. • For 437MHZ, a 7mm thick mild steel former was used. • For 145 MHz a 2 cm diameter wrought iron former was used. • Both these formers were customized in the ACE workshop.
Why LMR 400? LMR 400 RG 214 Attenuation 8.57 dB/100m at 145 MHz 15.95 dB/100m at 437 MHz Max Operating Temperature: 75 ˚C Cost: INR 500/m • Attenuation: • 5 dB/100m at 145 MHz • 8.9 dB/100m at 437 MHz • Max Operating temperature: 85 ˚C • Cost: INR 85/m
Why Antenna Rotator? • Dynamic Az/El trackingis a necessity for precision in readings and to avoid errors. • Manual tracking is not practical given the short Satellite pass duration , strength of signal being received & weight of antenna setup. • Though designing a rotor system is an option but you will need to take care of many factors • Water Proofing Motor framing • Wiring & Insulation • Wind load Considerations • Most importantly ACCURACY!! 4-Crossed Yagi-Uda Rotator Setup • Options Available • Yaesu G5500 • Hygain • Kenpro
Good option : YaesuG-5500 • Specifications • Rotation Range: • Elevation: 180°0 • Azimuth: 450° • Maximum Vertical Load • :Elevation: 30 kg or less • Azimuth:. (200 kg) or less • Rotation Time (Non Loaded) • :Elevation (180°): 67 sec at 60 Hz • Azimuth (360°): 58 sec at 60 Hz • Comes with a controller which helps in interfacing with a PC based tracking software
RCI-SE Board • Provides efficient control in both Azimuth and Elevation Planes • Compatible with most of the Antenna rotators available • This controller board takes care of all the Talking ! (Interfacing )between the PC –Software (Orbitron/Satscape ) and Antenna rotator(Yaesu G5500) • 5 relays (Azimuth and Elevation Control) • Left • Right • Up • Down • AUX, Brake or Speed control. RCI-SE Controller • Specifications: • 5 Relays • 2 x 8 Bit ADCs • LPT Interface Port
Wouxunvs ADF WOUXUN- KGUVD1P ADF 7020 Sensitivity upto -118 dBm No inbuilt LNA or BFO VFO is not Field Programmable. Delicate , requires ESD protection. Powered by power supply. External peripheral components required. No license required. • Sensitivity upto -125 dBm • Inbuilt LNA & BFO. • Field Programmable VFO to offset satellite Doppler shift. • Rugged and Robust. • Powered by Li-ion battery. • Plug and play device. • Requires operating license
WOUXUN KG UVD-1P ADF 7020
LNA ZX 60 33 LN+ • Frequency 50- 3000Mhz • Noise figure; 1.1dB • Gain 20.5 dB • i/p VSWR 2:1 • o/p VSWR 1.6:1 • DC Supply Voltage 5V • Supply Current 70mA • Operating Temperature -40’C to 85’C
AD 8302 • Polarization Measurement Kit (Phase and Gain Detector) • 2 Inputs from 1 Crossed Yagi • 2 Outputs to be given to µController
CC 1020 • It is industrial grade Trans- receiver IC. • It is operational over a frequency band of 405MHz to 470 MHz and is tunable. • It’s power requirements are low (-118dbm) Signal received at Ground-station would be -110dbm. • It supports packet data transmission. • Maximum bit rate is 156.2 kbps which is much higher than our requirements.
Satellite Tracking Software SATSCAPE: • Inbuilt WISP – DDE protocol to interface with compatible rotor system. (Yeasu G-5500) • Real time Tracking . • Built in Voice Alerts. • Wide range of satellites which can be tracked. • 3-D Graphic User Interface • It’s a FREEWARE !
Objectives Achieved • Crossed Yagi antenna successfully designed, fabricated & characterized. • Power link budget implemented. • CC 1020 and AD 8302 ordered and procured. • Ground-Station Control Room set up. • Softwares like 4NEC2, Solid Works, Satscape, Smart RF Studio were studied and used.
Experiments Conducted • AX.25 protocol studied using Slow Scan TV on commercial UHF Band . • Morse Code transmission/reception. • Radio Telescope was setup to monitor solar radiations. • Tracked ISS. • Radio propagation conditions were studied at the control room by setting up VHF/UHF monitoring station.
Student Outreach Program ACE • Blog and Facebook profile was created to reach out to the students & interested people. • Blog: http://acegroundstation.blogspot.com/ • Facebook Profile Handle: Ace Satellite Ground-Station • Student Interactive Session was conducted.
Thank You
