Passive sonar

How to Use

Launch

roslaunch subjugator_launch passive_sonar.launch

Debugging

To Play Back a File

• Download oof.bin

• roslaunch subjugator_launch passive_sonar.launch environment:=file

To step through a file

• rosrun mil_tools stream_tcp_dump ~/Downloads/oof.bin --batch_size=960000 --advance_on_arrow=True

To Play back a file at real speed

• rosrun mil_tools stream_tcp_dump ~/Downloads/oof.bin --batch_size=960000 --rate=10

Visualize Data in the Pipeline

This pipeline makes use of the mil_common/utils/mil_tools/mil_ros_tools/plotter.py utility to plot batches of data over on ROS Topics as CV2 images at most points in the processiong pipeline.

To view all points of the triggering pipeline

(raw, max convolution, gradient) that caused the most recent trigger (only hydrophone 0), look at /hydrophones/triggering/trigger_debug

It should look something like this (30kHz):

To view raw samples from all hydrophones around the triggering time

look at /hydrophones/triggering/sample_at_trigger_debug

It should look something like this (30kHz):

To view the frequency response of the bandpass filter

open /hydrophones/triggering/filter_debug in rviz. Then, in a new panel rosservice call /hydrophones/triggering/filter_debug_trigger "{}" Go look at the rviz and see the frequency response of the filter cropped for our general frequency range.

It should look something like this (30kHz):

To view the signals sent to the ping locator node

(and vertical lines at the trigger times) view /hydrophones/ping_locator/samples_debug NOTE:The Vertical lines are where triggering is detected on each hydrophone channel.

It should look something like this (90deg to the right):

To view the cross correlations between the hydrophones

(and therefore the time delays) look at /hydrophones/ping_locator/cross_correlation_debug NOTE:The Vertical lines are the max of the cross correleation and therefore the negative of the time delays.

It should look something like this (90deg to the right):

Configuration

All parameters that are expected to be changed in tuining are ROS Params initialized in passive_sonar.yaml

To make a custom configuration

• roscd subjugator_launch

• cp config/passive_sonar.yaml config/my_passive_sonar.yaml

• rosed my_passive_sonar.yaml

• change whatever parameters you like

• roslaunch subjugator_launch passive_sonar.launch config_file:=my_passive_sonar.yaml

To change the configuration at runtime

• set whatever param you want to change ie:rosparam set /hydrophones/triggering/target_frequency 25000

• call the reset service ie: rosservice call /hydrophones/triggering/reset "{}"

Testing ROS bridge

• Download example TCP dump,

• Run ROS bridge rosrun mil_passive_sonar sylphase_sonar_ros_bridge _port:=10001 _ip:=127.0.0.1

• Either stream a TCP dump or run the driver on a real robot * Stream TCP dump rosrun mil_tools stream_tcp_dump  ~/Downloads/oof.bin --port=10001 --ip 127.0.0.1 * On Sub8 run the actual driver (cd ~/.mil/sylphase-sonar/; ./driver/publish 10001)

• Make sure samples are being published rostopic echo /samples

How Does It Work?