I am looking for advises from advanced users to test the faisability of my project. Any experience shared are welcome. Sorry in advance for my english.
Here it is: I want to build a submarine or submersible boat equipped with a GPS antenna and a sonar. With it, I want to make surveys on lakes were the system will follow lines and move along them on it’s own. While moving, I want the system to ping the bottom and record the value to use them latter to do a bathymetric map of the lake. From time to time I want the system to stop and engage a dive to the bottom (the system will have a waterquality set of sensors attach).
While diving, 2 things puzzle me. The system will lost communication with the base (I don’t want any tethers) and 2, the GPS will also be lost. Ok, for that moment, the system can still slowly dive to the bottom, record water quality data and with the bar30 sensor + the sonar, I should manage to program a dive to the bottom and up again. At the surface, the system wait for getting GPS signal back, reposition itself on the track and continu the bathymetric survey. Can this be done with the blue robotic controller set ? The water quality sensor is something I have build - no issu there. But I never use Ardusub. From what I read ardusub + bar30 and GPS apparently can fix my tracking at the surface. I am just unsure of how ardusub and pixhawk or other controller will behave when loosing gps signal?
Also, to have precise sonar data, I have to keep the submarine rolling at minimum but still keep it at the surface were waves and wind are present to get my GPS positionning. Do a sub behave better below the water line or floating on top of it? If I use a submarine, I plan to mount a fix antenna for the GPS and keep the sub 30 cm below the surface (using somehow the Z from the GPS position as a “altimeter” reference) while the antenna protrude out of the water. This way I have the z from the GPS + the sonar value for the bottom but I also keep the submarine below the surface to escape waves. I assume it will be more stable like this but I really have no clue about all of this. Do you mind sharing opinion? The blue rov is maybe not the best match for this? It is bulky and maybe more prone to moving sideway because of wind and waves. I don’t know?
many thanks for any input.