Tracking scenario simulation problems for active sonar sensor

I am attempting to use the Sensor Fusion and Tracking Toolbox for active sonar applications. I started with the simulation of a tracking scenario and encountered some problems.

For active sonar The FieldOfView property and the MountingAngles property should be defined separately for the emitter and for the receiver sonar. However, matlab produces a warning (that these properties are not revent in this system configuration). Furthermore, when obtaining detections using the sonar object the output rxConfigsdoes not get the the FieldOfView property and the MountingAngles defined for the sonar sensor, but only those of the emitter.

Matlab warning after definition of properties

Furthermore, the command below

[detections, numDets, rxConfigs] = sonar(sigs,txConfigs,timeSim);

produces only false alarms, no target detections are produced.

[Gowtham]

Hello miri,

To understand the issue more clearly, could you provide more information about the context along with the sample code snippet?

[miri doron]

I want to model a mono-static active sonar, whose receiving Field of view is 360 degrees in azimuth (omni-directional), however the transmission of the array may be directional at a given direction (phased array transmission). Thus, the sonar array has a different FieldOfView when it is in receiving mode and when it is in directional transmission mode. Also, I would like to define the transmitter beam direction using the mounting angle parameter. However, the software does not support defining the FieldOfView and the MountingAngles properties, separately for sonar and emitter.

[Gowtham]

Hi Miri,

I have understood the requirement, but I need a sample code describing the functions used in order to further investigate the issue. Is it possible for you to share the relevant files or provide a sample code? This would be very helpful in providing effective assistance.

Answer 1

[miri doron]

I attached below a toyModel code demonstrating my problems.

“ToyModel” is the main script, the function “getTrajCV” computes the trajectory waypoints and times of arrival for constant velocity model, and function “sonarProps” defines sonar and emitter properties.

ToyModel consists of 2 parts: first we calculate and plot trajectories of sonarShip platform and target platform. The second part, beginning at line 72, models a sonar Sensor and a sonar emitter and simulates its detections.

Since the command

 % Obtain the sonar detections using the sonar object.
    [detections, numDets, rxConfigs] = sonar(sigs,txConfigs,timeSim); 

produced only false alarms, no target detections were produced. I had to simulate the target detections myself.

In the final plot below we mark the “detections” created by sonarSensor object “sonar” (line 124) as magenta Asterisk, and the noisy target measurements which I computed separately are marked by black plus. We see from the plot that the sonarSensor object produces only false alarms, no target detections are produced

Answer 2

[Gowtham]

Hello Miri,

I understand that you are utilizing the Sensor Fusion and Tracking Toolbox to simulate a tracking scenario and have come across a warning related to the properties of the sonarSensor object.

Upon reviewing your provided code snippet, I attempted to run it at my end. As a result, I encountered the following warning message:

Upon considering the provided information, it appears that the issue is related to the setProperties function within the ScanningMount class.

It is likely that there are other properties within the sonarSensor object that are taking precedence over the 'FieldOfView' and 'MountingAngles' properties, resulting in the warning message. To address this, I recommend reviewing the dependencies and interactions of these properties with others to ensure they are properly configured.

Additionally, resolving this warning may also help resolve the issue with 'rxConfigs' that you mentioned earlier. By addressing the warning and ensuring the correct configuration of properties, it is possible that the issue with 'rxConfigs' will be resolved as well.

Kindly refer to the following MATLAB documentation for further understanding on ‘sonarSensor’ object, ‘setProperties’ function and ‘inactive property’

• https://www.mathworks.com/help/releases/R2022b/fusion/ref/sonarsensor-system-object.html
• https://www.mathworks.com/help/releases/R2022b/matlab/ref/matlab.system.setproperties.html
• https://www.mathworks.com/help/releases/R2022b/matlab/ref/matlab.system.isinactivepropertyimpl.html

Hope this helps.

Best Regards,

Gowtham

[miri doron]

Yes, the toolbox does not support defining the FieldOfView property and the MountingAngles property for the sonar if an EmitterIndex property is specified, since it assumes that these properties must be identical for sonar and emitter. (see function ammended sonarPropsToy attached, no warnings are given now)

However, even when we accept this limitation and remove these property definitions from the sonar sensor, no detections of the target are produced