Unmanned Aircraft Systems for Radio Echo Sounding

1. Unmanned Aircraft Systems for Radio Echo Sounding

2. Outline • CReSIS Platforms Overview • Meridian UAS Status Update (MediumUASs) • 40% Yak UAS Status Update (Small UASs) • Sensor Platform Integration (Other UASs) • Future Developments, Plans and Challenges

3. What do the >700 Available UAV Platforms Offer?

4. KU Unmanned Aircraft

5. Sensors – UAS-Based Radar • Design Evolution is ongoing Eight transmit/receive channelsdigital beamsteering and interferometry Eight data acquisition channels12-bits, 111-MHz sampling rate Volume: 50 x 50 x 20 cm Mass: 55 kg Input power: 400 W Small form factor for RF modules Custom antenna elements 3.2-lb Vivaldi antenna (51 x 40 x 0.32 cm)162 to 1121 MHz 195-MHz center frequency30-MHz bandwidth scaled down 2-channel version is developed for UAS field tests

6. Meridian UAS Overview For more information, contact: Rick Hale, PhD, Associate Professor, Aerospace Engineering 1530 W 15th St., 2120 Learned Hall, Lawrence, KS 66045 785-864-2949, rhale@ku.edu, www.cresis.ku.edu

7. Multi-Mission Science-Driven Payload Options Magnetometer Optical/Infrared Camera Aerosol Detection RADAR Antennas

8. Meridian UAS range and endurance improve with reduced cruise, reduced payload weight or higher altitude missions

9. Meridian UAS Flight Test History: Configurations and Fields August 28th, 2009 December 31st, 2009 July 17 – August 12, 2011; December 20, 2011 September 10th-15th, 2009

10. Meridian UAS System Improvements • Installation of Thielert Centurion 2.0 engine, and removal of ground cart • Lower weight cowling (12 lbs) • Redundant 2.4GHz receivers, with frequency hopping for lower risk of interference or jamming • Improved avionics package and starting sequence • Improved safety features (external power, tethered engine kill) • Common avionics on 40% Yak enables more frequent training • Flight tests for assisted landing modes • First COA application in review to enable training and operation in National Airspace

11. Depth Sounder (MCoRDS) Progress Hardware Updates • 4-Channel RF Receiver in a 3U PXI Form Factor. • Reduced Size. • Easy Integration into Digital System. • Adapted to Other Systems. • 1kW T/R Module. • Power Amplifier and Duplexer Tested and Thermal Images at 1kW Operation. • Improve System Sensitivity.

12. 40% Yak “Trainer” Is Also Being Equipped with Dual Low Frequency Sounder • Local flights imminent; potential Alaska mission in August pending COA;Antarctic deployment December 2013; Greenland deployment March 2014

13. Dual Low Frequency Sounder • Miniaturized system for small UAS operation. • 14 and 35 MHz. • 100-200 W Tx Power. • 10 lbs. • Antennas integrated into the UAS structure. • 2-D Aperture Synthesis. • Sub systems applicable to other sensors. • Backpack portable. • Snow/Ku-Band Systems. 100-Watts Pulsed Amplifier (230 gr.) (image from SpinCoreInc). • Compact Digital System. • Prototype Version. • Embedded Microblaze Processing Core for command, control, data acq. & storage. • Mixed Signal Front End (ADC/DAC/Clock). • Single Chip RF Receiver (LNA/VGA/LPF). • SD-Card Storage (128 GB, ~2MB/sec). • Integrated GPS receiver. • Future hardware teaching platform (DSP/FPGA).

14. Snow Radar Results • Satellite can be used to estimate sea ice thickness from freeboard measurements. • Significant error can arise from unknown snow loading. • Laser will overestimate thickness. • Radar is more complicated because the reflecting surface depends on snow conditions. • Snow cover modulates heat transfer between the atmosphere and the ocean. Interface Tracking: Snow Thickness and Accumulation Rates. Weddell Sea Comparison of Snow Radar with AMSR-E derived snow depth.

15. Ikhana/Sierra Snow Radar • Miniaturized version of the snow radar for UAS deployments. • Compact COTS Controller & DAQ. • Custom wideband chirping PLL. • Autonomous Operation. • Originally targeted for NASA Ikhanaplatform with modifications for Sierra. Ikhana http://www.nasa.gov/centers/dryden/news/FactSheets/FS-097-DFRC.html

16. Mizoplex/Ikhana/Sierra • Range: 600 Nmi • Endurance: 10 hours • Power: 19Amps @ 28 V DC • Useful Payload: 100 lbs • Max Altitude: 12,000 ft • Air Speed: 60 knots Sea Ice Flight Tests, Alaska, July/August 2013

17. Precision Formation Flight Requires Coordinated Sensor and Platform Development

18. Improved Command and Control: Advanced Nonlinear Controller for UAS Experience gained from the 2011 campaign has helped to define new priorities in the control and command side research. Over-the-horizon flights and CReSIS missions in hostile polar regions demand adaptive and resilient controllers. To meet safety and performance requirements in unstructured environment (e.g. Polar Regions), a new nonlinear model predictive controller and an adaptive guidance logic are designed for CReSIS UASs . Performance of new Meridian’s NMPC Trajectory Following: Controller in Presence of Cross-Wind Adaptation of Controller to a 20% Intentional Reduction 3D Flight Views of CL0 (e.g. damage or impairment)

19. GlobalHawk/Ventures

20. EMI Testing and Mitigation • CReSIS radars are capable of detecting signals on the order of nanovolts • EMI can dramatically degrade radar performance and interfere with UAS operation and control • We have taken a proactive attitude toward EMI and EMC issues • Purchased a 4x8 meter chamber • Conducted tests at the Sprint chamber • Submitted MRI proposal to develop a 10-meter chamber at CReSIS/KU • Example: reduction of a 150 MHz source radiating from a compact PCI power supply

21. CReSIS Anechoic Chamber FacilityNSF MRI Project • The Chamber has become an extremely useful and valuable asset for Radar/Avionics/System design and testing. • EMI identification and reduction. • Improve sensor sensitivity. • Reduce interference between sensors and avionics. • Test systems at full power. • Measure antenna gain and efficiency. • Measure array patterns and mutual coupling. • Industry collaborations. • Student Education. • Fully functional in Summer 2012. • chamber.ku.edu Sensor Noise Reduction Platform and sensor interference mitigation. Antenna Pattern and Coupling

22. Anechoic Chamber Use • P-3 MCoRDS Array Analysis. • Identified differences in element radiation patterns. • Need to characterize to correctly reduce surface clutter. • Radar Electronics Noise Analysis. • Routine measurements of all new equipment and upgrades to characterize noise. • HF Sounder. • Antenna Pattern & Efficiency. • Reduction in Antenna Performance due to proximity of servo wires. • Interference from Avionics. • Increased noise floor due to servo control transients.

23. Sensor Platform Integration Simulated and experimental data confirms compensation techniques for wing flexure induced pattern rotation and shifting and filling of nulls; more important with small flexible airframes typical in UAS

24. Summary and Plans • Continued emphasis on ground and flight tests and sensor integration for upcoming deployments • Dual low frequency sounder on Yak G1X • UAS radar on Meridian • UWB radar on Basler • Continued support of other external platform integration • Pursue new opportunities