Level finding using multiple search steps

A computer program product, comprising:

• a non-transitory data storage medium that includes program instructions executable by a processor to enable said processor to execute a method of level finding having a coarse search and a fine search, said computer program product including:
• code for accessing parameters including characteristics of a shape of a transmitted pulse in time domain launched by a transmitter onto a waveguide into a tank having at least one material therein, physical properties of said waveguide and real (phase) and imaginary (attenuation) dielectric characteristics of said material at a frequency of said transmitted pulse;
• code for said coarse search including minimizing a prediction error between a reflection signal (echo curve y(k)) and a sampled pulse model echo p(k) to obtain an objective function J(k) in a vicinity of a minimum prediction error (k*), and
• code for said fine search after said coarse search calculating at least one minimum or maximum using said J(k) in said vicinity of said k*, wherein said minimum or said maximum corresponds to a level of said material or an interface involving said material.

A pulsed radar or ultrasound level gauge (level gauge), comprising:

• a processor having an associated memory storing a level finding algorithm having a coarse search and a fine search;
• a pulse generator (PGen) block that is coupled to receive control signals originating from said processor;
• a transceiver for coupling to a waveguide in a tank having at least one material therein having an input coupled to an output of said PGen block for transmitting transmitted pulses and an output coupled through a sensor to an input of said processor for processing echo signals received responsive to said transmitted pulses;
• said level finding algorithm when implemented by said processor having provided parameters including characteristics of a shape of said transmitted pulses in time domain, physical properties of said waveguide and real (phase) and imaginary (attenuation) dielectric characteristics of said material at a frequency of said transmitted pulses causing:
• said coarse search minimizing a prediction error between said echo signal (echo curve y(k)) and a sampled pulse model echo p(k) to obtain an objective function J(k) in a vicinity of a minimum prediction error (k*), and
• said fine search calculating at least one minimum or maximum using said J(k) in said vicinity of said k*, wherein said minimum or said maximum corresponds to a level of said material or an interface involving said material.