Evaluation of Commercial Radar Sensors for Proximity Fuze Applications

Abstract: Radar sensors has been known for their usage in military applications but during the last decade commercial radar sensors have been implemented for usage in for example advanced driver-assistance system. One common implementation for advanced driver-assistance system is the adaptive cruise control technology implemented in vehicles to help it adapt the velocity based on the distance to a detected vehicle in front. The development of the commercial radar sensors have made radar sensors cheaper and more accessible. The goal of this thesis is to investigate the civil market to see if there are any radar sensors available that could be of interest to use for applications in proximity fuzes. A proximity fuze can be used in projectiles to initiates its explosion when the projectile is positioned an optimal distance from the target where the distance can be estimated by using a radar system. Investigation of the civil market was made by performing a literature study by looking into articles about civil use applications for frequency modulated continuous wave radars and pulsed Doppler radars operating with a frequency in the GHz-area. In the literature study, five interesting frequencies were identified for the frequency modulated continuous wave radar: 24 GHz, 35 GHz, 77 GHz, 94 GHz and 122 GHz. For each article different properties regarding the sensors’ performance was investigated. Example of a few of the properties investigated was the sensor’s limitation of maximum range, angle and velocity. Based on the literature study’s result a 77 GHz radar sensor included in an evaluation kit was ordered and used to perform a proof-of-concept where the radar sensor’s performance was evaluated. The proof-of-concept was made by analyzing if the radar sensor could detect a drone at distances between 5 m and 20 m at rest or moving with a velocity of approximately 3 m/s. Two scenarios were tested for the drone and the sensor. In the first scenario, possible background clutter was eliminated while the second scenario included some background clutter. The sensor was able to detect the drone at all positions when moving or at rest, but for the second scenario there were some difficulties to get a clear detection of the target at 10 m and 20 m distance. Distance and angle measurements were performed on a metal plate having a larger radar cross section than the drone. The evaluation kit was able to detect the object at distances between 5 m and 20 m and when the object was placed 10 m away from the sensor in both x- and y-direction i.e. 45 ° from the sensor. From these results it could be concluded that radar sensors used for automotive applications has potential to be used for proximity fuze applications but further tests have to be made before a definitive conclusion can be made. The sensor has to be tested for higher velocities than 500 m/s and for larger distances to be able to determine if this type of sensor could be applied in proximity fuzes.