Automotive Synthetic Aperture Radar System based on 24 GHz Series - PowerPoint PPT Presentation

Automotive Synthetic Aperture Radar System based on 24 GHz Series Sensors Fabian Harrer 26.09.2017 26.09.2017 Fabian Harrer 1

Cooperation Project 26.09.2017 Fabian Harrer 2

Motivation for radar • Independent of environment, such as rain, fog • Suitable for a hidden integration in the vehicle • Low azimuth resolution for aperture sizes used in automotive 26.09.2017 Fabian Harrer 3

Synthetic Aperture Radar (SAR) • Increasing the aperture with moving antennas: SAR • Known as remote sensing application for airplanes/ satellites • Resolution is range independent • Series sensor • Vehicle internal odometry based on wheel ticks and gyroscope • Single channel is sufficient 26.09.2017 Fabian Harrer 4

Overview • Fully integrated in the vehicle • No additional hardware necessary • Post processing on the normal radar ADC data 26.09.2017 Fabian Harrer 5

SAR principle • Multiple mea- surements are combined to form a huge aperture aperture 26.09.2017 Fabian Harrer 6

Contents 1 Performance estimation Evaluation of automotive relevant SAR properties 2 Measurement 3 Conclusion + Outlook 4 26.09.2017 Fabian Harrer 7

Contents 1 Performance estimation Evaluation of automotive relevant SAR properties 2 Measurement 3 Conclusion + Outlook 4 26.09.2017 Fabian Harrer 8

Performance estimation radar frequency band maximum azimuth resolution real aperture synthetic aperture, (2 m) range independent (2 m) 9 . 0 ◦ � 24 . 05 GHz to 24 . 25 GHz = 316 mm 5 . 8 mm � = 0 . 17 ◦ 2 . 8 ◦ � 76 GHz to 77 GHz = 98 mm 1 . 8 mm � = 0 . 05 ◦ 2 . 8 ◦ � 77 GHz to 81 GHz = 98 mm 1 . 8 mm � = 0 . 05 ◦ radar frequency band maximum range resolution 24 . 05 GHz to 24 . 25 GHz 75 cm 76 GHz to 77 GHz 15 cm 77 GHz to 81 GHz 5 cm 26.09.2017 Fabian Harrer 9

Contents 1 Performance estimation Evaluation of automotive relevant SAR properties 2 Measurement 3 Conclusion + Outlook 4 26.09.2017 Fabian Harrer 10

Parameters • Carrier frequency 24 GHz • Bandwidth 150 MHz • Range resolution 1 m • Sampling rate 2 mm • Single channel • Antenna beamwidth 60 ◦ 26.09.2017 Fabian Harrer 11

Undistorted SAR measurement 0 0 Normalized Amplitude in dB • Measurement − 5 − 2 of a corner North in m reflector − 10 • High azimuth − 4 resolution − 15 • Low range − 6 resolution at 24 GHz − 20 0 2 4 6 East in m 26.09.2017 Fabian Harrer 12

Incorrect trajectory measurement 0 0 Normalized Amplitude in dB • Linear trajectory − 5 − 2 (green line) North in m • Inaccurate − 10 odometry − 4 measurement (red line) − 15 − 6 • Azimuth resolution is − 20 0 2 4 6 lost East in m 26.09.2017 Fabian Harrer 13

Insufficient azimuth sampling 0 0 Normalized Amplitude in dB − 5 − 2 • Azimuth North in m sampling − 10 theorem not − 4 satisfied − 15 • Ambiguities − 6 arise − 20 0 2 4 6 East in m 26.09.2017 Fabian Harrer 14

Contents 1 Performance estimation Evaluation of automotive relevant SAR properties 2 Measurement 3 Conclusion + Outlook 4 26.09.2017 Fabian Harrer 15

Measurement 1 2 3 4 6 5 26.09.2017 Fabian Harrer 16

Measurement 10 0 8 1 2 3 4 6 − 5 5 6 5 − 10 4 − 15 2 1 2 3 4 Raw data, no threshold, no clustering 0 − 20 − 10 − 5 0 26.09.2017 Fabian Harrer 17

Contents 1 Performance estimation Evaluation of automotive relevant SAR properties 2 Measurement 3 Conclusion + Outlook 4 26.09.2017 Fabian Harrer 18

Conclusion + Outlook • SAR processing is possible using series sensors and odometry • 24 GHz band limited by range resolution • Extension to 77 GHz necessary 26.09.2017 Fabian Harrer 19