traffic surveillance process and device

• US 5,767,794 A
• Filed: 01/24/1996
• Issued: 06/16/1998
• Est. Priority Date: 08/06/1993
• Status: Expired due to Fees

• Current Assignee: Leica Geosystems AG (Hexagon AB)
• Original Assignee: Leica Sensortechnik GmbH
• Inventors: Borsch, Manfred, Pfaff, Reiner
• Primary Examiner(s): Hofsass, Jeffery
• Assistant Examiner(s): Lieu, Julie B.
• Application Number:
  US08/578,547
• Time in Patent Office: 874 Days
• Field of Search: 340/937, 340/936, 340/933, 340/942, 340/905, 348/148, 348/149, 364/436, 364/438, 352/113
• US Class Current: 340/937
• CPC Class Codes: G01P 1/10 for indicating predetermined speeds
• CPC Class Codes: G01P 1/122 Speed recorders
• CPC Class Codes: G01S 13/86 Combinations of radar systems with non-radar systems, e.g. sonar, direction finder
• CPC Class Codes: G01S 13/92 for velocity measurement
• CPC Class Codes: G01S 17/88 Lidar systems specially adapted for specific applications
• CPC Class Codes: G08G 1/054 photographing overspeeding vehicles
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast
• CPC Class Codes: H04N 7/183 for receiving images from a single remote source

Abstract

A traffic surveillance system measures a speed of a vehicle within a traffic scene, optically records the traffic scene, and reproduces the traffic scene on a display in synchronism with a display of the measured speed. The system includes a speed sensor which measures the speed of the vehicle within the traffic scene and an electro-optical camera having a recording medium in which video signals representing the traffic scene are stored. The camera is equipped with an audio input and output connected to a soundtrack of the recording medium. The audio input receives modulated signals of the measured speed for storage in the soundtrack in synchronism with the video signals. The measured speed signals and the video signals are combined in a video mixer and reproduced on the display.

Claims

1. A method of surveying a traffic scene comprising the steps of:

measuring a speed of a vehicle within the traffic scene with a speed sensor and converting the measured speed into modulated signals;

optically recording the traffic scene in a recording medium of an electro-optical camera;

storing said modulated signals on a soundtrack of the recording medium in synchronism with the optically recorded traffic scene; and

displaying the optically recorded traffic scene on a reproduction device in synchronism with a display of the measured speed.

2. The method according to claim 1, wherein the steps of measuring and optically recording capture a traffic scene of approaching vehicles.

3. The method according to claim 1, further comprising the steps of:

converting the modulated signals which are stored on the soundtrack into demodulated signals; and

mixing the demodulated signals with video signals generated by the step of optically recording prior to the step of displaying.

4. An apparatus for surveying a traffic scene comprising:

a speed sensor to measure a speed of a vehicle within the traffic scene;

a modulator to generate modulated signals which represent the measured speed;

an electro-optical camera having a recording medium in which video signals representing the traffic scene are stored and an audio input and output connected to a soundtrack of the recording medium, said audio input receiving said modulated signals for storage on the soundtrack;

a demodulator to convert the modulated signals which are received from the audio output of said electro-optical camera into demodulated signals; and

a display to display the measured speed in accordance with the demodulated signals.

5. The apparatus according to claim 4, further comprising a video mixer for receiving and mixing the demodulated signals and the video signals of the traffic scene, wherein said display receives the mixed signals and reproduces the traffic scene and the measured speed in accordance with the video signals and the demodulated signals.

6. The apparatus according to claim 5, wherein the modulated signals which represent the measured speed are stored in synchronism with the video signals of the traffic scene and the demodulated signals which represent the measured speed are reproduced in synchronism with the video signals of the traffic scene.

7. The apparatus according to claim 4, wherein the speed sensor has a memory for storing a threshold value.

8. The apparatus according to claim 7, wherein said display prevents display of the measured speed if the measured speed is lower than the threshold value.

9. The apparatus according to claim 4, wherein the speed sensor, the electro-optical camera and the modulator are arranged in a common housing.

10. The apparatus according to claim 9, wherein the demodulator is a subassembly which is separate from the common housing for the speed sensor, the electro-optical camera and the modulator.