Ultrasonic range sensor arrays (URSA) are widely used in robotics in order to explore the environment. A novel concept for near field sonar (< 2m) is presented which comprises the following features: 1) Sensors with wide angle ultrasonic coils are used in order to cover the field of view with only few sensors. 2) All sensors of the array work simultaneously, because stochastic coding is applied. 3) Cross talk (intra-system interference) between the individual sensors of the array is compensated and evaluated in order to get an improved image formation. An additional object tracking algorithm allows further noise reduction. 4) Automatic calibration of the sensor positions. Experimental results are presented, which show that image formation is possible at a rate of 10 frames per second.