METHOD AND DEVICE FOR EVALUATING ECHO SIGNALS WITH ECHO SOUNDING SYSTEMS HAVING DIGITAL INDICATION

• US 3,739,325 A
• Filed: 06/10/1971
• Issued: 06/12/1973
• Est. Priority Date: 06/13/1970
• Status: Expired due to Term

• Current Assignee: Reinhard Ludwig
• Original Assignee: Reinhard Ludwig
• Inventors: Ludwig, Reinhard
• Primary Examiner(s): Farley, Richard A.
• Application Number:
  US05/151,847
• Time in Patent Office: 733 Days
• Field of Search: 340/1C,1R,3R
• US Class Current: 367/108
• CPC Class Codes: G01S 15/18 wherein range gates are used
• CPC Class Codes: G01S 7/527 Extracting wanted echo signals Doppler systems G01S15/50

Abstract

Method of evaluating echo signals with echo sounding systems having digital indication of the sounding depth determined by the transmission time of the bottom echo includes comparing the transmission time of at least those echo signals having the intensity of bottom echos appearing in a given sounding period with the transmission time corresponding to the sounding results of a preceding sounding period and, from these echo signals, evaluating as bottom echo that signal having a transmission time differing least from the transmission time of the echo signal evaluated as bottom echo in the preceding sounding period; and system for carrying out the method.

Claims

1. System for carrying out a method of evaluating echo signals with echo sounding systems having digital indication of the sounding depth determined by the transmission time of the bottom echo, comprising a pulse generator for generating pulses as time traces which is actuable simultaneously with transmission of a sounding pulse, a pulse counter connected to said pulse generator for receiving time tracing pulses therefrom, a first storage connected to said pulse counter for storing a momentary pulse counter reading in response to all echo signals of given minimum intensity, a second storage connected to said first storage for receiving therefrom data content of said first storage at latest by the start of a next succeeding sounding period, comparator means connected to said pulse counter and said second storage for continuously comparing the reading of said counter with the data content of said second storage, said comparator means having an output, a sawtooth wave generator connected to said output of said comparator means and controllable thereby so as to emit an increasing and decreasing voltage whenever the counter reading is respectively less than and exceeds the data content of said second storage, AND-gate means having a first input, a transistor stage having an output connected to said first input of said ANDgate means said transistor stage being controllably connected to said sawtooth generator for emitting a logical L for a sawtooth wave voltage NOT = 0, receiver means for the echo signals, said AND-gate means having a second input connected to said receiveR means, switch means for said first storage for releasing the stored data content thereof, and other switch means for resetting the output voltage of said sawtooth wave generator to zero, said AND-gate means having an output connected to both of said switch means.

2. System according to claim 1 wherein said sawtooth wave generator is comprised of a Miller integrator.

3. System according to claim 2 wherein said transistor stage also forms part of said Miller integrator.

4. System according to claim 1 wherein said echo signal receiver means comprises a differential amplifier having an output and an inverting and a non-inverting input, an echo signal receiving channel connected to said non-inverting input, a charging capacitance of a peak value rectifier circuit connected to said inverting input, said rectifier circuit having an input connected to the output of said differential amplifier.