Video imaging using multi-ping sonar

Abstract

A sonar system comprising a sonar transmitter, a very large array two dimensional sonar receiver, and a beamformer section transmits a series of sonar pings into an ensonified volume of fluid at a rate greater than 5 pings per second, receives sonar signals reflected and scattered from objects in the ensonified volume, and beamforms the reflected signals to provide a video presentation and/or to store the beamformed data for later use. The parameters controlling the sonar system are changed so that the beamformer section treats the data from the receiver section with more than one set of parameters. The stream of data is treated either in parallel or in series by different beamforming methods so that at least one beam from the beamformer has more than one value.

1 . A method of recording a 3D sonar image, comprising;
 a) transmitting a series of sonar pings into a first volume of water, the series of sonar pings transmitted from a sonar ping transmitting device at a rate at least 5 pings per second, wherein the sonar ping transmitting device is controlled by sonar ping transmitting parameters, and wherein each sonar ping transmitting parameter is chosen from predetermined list of sonar transmitting parameter settings;   b) receiving sonar signals reflected or scattered from objects in the first volume of water from each of the series of sonar pings, the received sonar signals received by a large two dimensional array sonar receiving device;   c) wherein the sonar receiving device is controlled by sonar receiving parameters, and;   d) beamforming the received sonar signals from each of the series of sonar pings with a sonar beamforming device to form a three dimensional (3D) sonar image of the objects reflecting or scattering the received sonar signals, wherein the sonar beamforming device is controlled by a set of sonar beamforming parameters, and wherein each sonar beamforming device parameter is chosen from predetermined list of sonar beamforming device parameter settings;   e) changing at least one beamforming parameter in the time between any two sonar pings of the series of sonar pings to produce at least two real time beamformed data sets for the same ping; and   f) combining the at least two real time beamformed data sets to produce a single video frame image in the time between two sonar pings.   
     
     
         2 . The method of  claim 1 , where the combined beamformed data sets have more than one value for at least one beam. 
     
     
         3 . The method of  claim 2 , where the two real time data sets are the FAT data set and the MAX data set. 
     
     
         4 . The method of  claim 2 , where the two real time data sets have different range settings. 
     
     
         5 . The method of  claim 2 , where the two real time data sets have different time varying gain (TVG) settings. 
     
     
         6 . The method of  claim 2 , where the two real time data sets have different Field-of-View (FOV) settings. 
     
     
         7 . A method of real time three dimensional (3D) sonar imaging, comprising:
 a) insonifying a volume of fluid with a series of sonar pings, the sonar pings, wherein the series of sonar pings are produced at a rate greater than 5 pings a second;   b) receiving for each of the series of sonar pings sonar signals reflected from one or more objects in the volume of fluid, wherein the sonar signals are received with a large 2D array of sonar signal detectors;   c) beamforming the reflected sonar signals to provide a series of (3D) sonar images of the one or more objects; wherein the beamforming procedure is changed from ping to ping to produce a series of images having different field of view (FOV) for each of at least two consecutive pings.   
     
     
         8 . The method of  claim 7 , further comprising;
 d) stitching at least two consecutive images of the series of 3D images produced in step c) to make a composite 3D image having a wider field of view than any one of the series of (3D) sonar images of step c).   
     
     
         9 . The method of  claim 8 , wherein four consecutive images of the series of 3D images having different fields of view are stitched together to produce a single image. 
     
     
         10 . The method of  claim 9 , further comprising;
 e) recording a video of the composite images of step d), wherein the video shows composite single images stitched from four consecutive images, the composite images shown sequentially at a rate greater than 5 images per second.   
     
     
         11 . The method of  claim 7 , further comprising;
 d) identifying an object of interest from at least one image of the series of 3D images of the one or more objects; and   e) changing the field of view of at least one succeeding ping is to provide further images of the object of interest.   
     
     
         12 . The method of  claim 11 , wherein step e) changes the field of view so that the beamformed image of the object of interest is approximately in the center of the changed field of view in succeeding pings. 
     
     
         13 . The method of  claim 7 , wherein step c) changing the beamforming procedure from ping to ping includes inserting a programmable set of delays in sonar signals received by each element of the large array of sonar signal detectors. 
     
     
         14 . The method of  claim 8 , wherein a subset of the at least two consecutive images of the series of 3D images is updated continuously to generate real time images. 
     
     
         15 . The method of  claim 8 , wherein intelligent processing is used to account for and/or track motion of moving objects. 
     
     
         16 . The method of  claim 8 , wherein predictive processing is used to account for and/or track motion of moving objects. 
     
     
         17 . The method of  claim 8 , wherein interframe alignment is used to account for and/or track motion of moving objects. 
     
     
         18 . The method of  claims 16 - 18 , wherein the portion of the field of view containing the motion of the moving objects is updated more frequently than the remaining portions of the field of view.