I see a screen shot of a tire on the ping sonar sales page. How did you obtain that with the speeds being so fast? It is there so I assume the ping created that image. I cannot find a way to slow mine to .00045 (example speed) as I can my Kongsberg Mesotech MS 1000 675 kHz scanning sonar. Your frequency can scan high resolution but It seems, or I cannot find, a setting to step down the speed in which the motor turns the transducer. If speeds can be slowed please let me know how. If they cannot a software and or mechanical fix is needed. For SAR work this can be a great tool which is why I purchased this. The need for a very slow moving sonar is important to identify targets in zero and low vis waterways which I mostly work in. Mark Michaud Founder (2) Southeast Louisiana Underwater Search and Recovery 501c3 | Facebook
Hi @MacGyver135, welcome to the forum
I’m a bit confused about what you’re asking about here. Ideally a scanning sonar would spend as little time as possible for each ping so that the scans update faster (similarly to how a 30fps video camera is preferable to one with the same resolution but only 2fps). Perhaps I’m misunderstanding what you mean by wanting to slow down the motor?
The motor in the Ping360 rotates with a step size (angle) of 1 gradian (0.9 degrees). You can increase the number of steps between each ping to get a lower angular resolution scan that moves faster, but the highest angular resolution is achieved by transmitting a ping and measuring the response at each motor step (set the Angular Resolution setting to 1 gradian). The motor doesn’t move while the ping is being transmitted or measured, so ideally the motor should move as fast as it can - slowing it down would just mean you get the same results slower, which is very unhelpful if the ROV or target are moving. If you’re asking about setting the motor step size smaller than 1 gradian then that would require a different motor or an integrated gear box, but note that the tire image you’re referring to was captured with our existing ping360 using a 1 gradian scan resolution.
It may be helpful to have a read through our Understanding and Using Scanning Sonars guide, and please let me know if you’ve got any follow-up questions
I have gotten some great images with the Ping360 in certain situations, and other times it was useless except as a navigation tool. It seems to completely depend on the environment and how the ROV is positioned (and pilot skill ).
I made a quick demonstration video a while ago. I don’t know if it’s helpful for your question or not, but shows my experience with it in that specific situation. I don’t know if it would be my first choice for a SAR sonar since a more advanced system or a better image created by a higher frequency would be extremly useful.
You can also identify about 3 tires about 20 feet away at the 8-9 o’clock positions.
Note that this includes distance to target, but also the pitch angle. If the sonar is angled downwards towards the front it can better image objects on the bottom (which is discussed in the Bottom Visibility section of our guide), and the steeper the angle the shorter the acoustic shadows are.
A pitch angle can be achieved by either an ROV with pitch control (e.g. the BlueROV2 heavy configuration), or by mounting the Ping360 at a slant. Note that when the sonar or ROV is pitched it can be a bit more difficult to navigate with a 360 view, as pitching down for extra ground coverage in front also means less ground coverage behind.
To address your confusion, Ideally a scanning sonar will run at very slow steps from a fixed position when a target is obtained, for my use. I own and operate a gen 1 humminbird 360 (455 kHz) and a Kongsberg Mesotech MS 1000 (675 kHz)scanning sonar. I have obtained solid images from both of victims, and other targets. I have obtained phenomenal images with my MS 1000. As far as understanding sonar, I am a very experienced and skilled operator with the 2 mentioned units as well as a Klein 3000 side scan sonar. I have been doing this a long time. That is not a challenge, just something to clarify my question. Most ROV’s primarily use multibeam sonar. The MS 1000 is attached to ROV’s for survey work and target acquisition in the commercial marine environment as well. Your move to make scanning sonar the primary on an ROV is a good move. The fastest speeds can be used for navigation as you mentioned. I have not splashed the unit yet but on a test check it seemed to move fast and I could not find a speed control as I have on the commercial MS1000 and the recreational HB 360. My use of the ROV will be secondary to the MS1000 or sidescan to verify an anomaly. I will already have a read on the area and bottom. I will guide the rov to it, sit still and scan for identity. At 756 kHz, it is neither low or high frequency by today’s standards. My Klein 3000 is 200 and 500 kHz and the newer side scan and scanning sonars can be up to 1800 kHz. Your frequency can provide decent range and clean imaging too. What I can’t figure out is how to step the speed down so I created the post. Your capturing that tire with gradian 1 is what I needed to know too. That is perfect for SAR work in the hands of a skilled and practiced operator. I am writing much of this reply as a thread concerning this discipline does not exist yet. I think the problem will be the learning curve on my end operationally as this is a new piece of equipment. Asking the source is the best way to find info or suggest a mod that will make this equipment of use to those in SAR with smaller budgets. Attached is an image from my MS1000 scanning sonar from 2018. Thanks for the response. It was very helpful.
Great video. That is the hands on help I was looking for. As far as not being good for SAR, that is incorrect. The resolution isn’t the concern as much as frequency and speed. Higher frequency, smaller range, lower frequency greater range. The image resolution will be there if the frequency and speeds are right. I have imaged bodies at 455 kHz that were clean and very detailed. At 16 ft range on your video, of the scan speed were half as fast the image would be more clean and detailed. The MS1000 speed of scan can be as a low as 0.225, 0.45, 0.9, 1.8, 3.6 and 7.2 degrees per step. The lowest speed provides the most clear imaging. This image is from a class I teach. The body is my training dummy. Scanning sonar is actually the most efficient sonar for SAR if used by the right operator.
I think I was confused by your terminology. If I understand correctly you were interested in “fine angular resolution”, which can be correlated with but is not the same as “slow scans”. Note that there are multiple other factors which influence scan speed:
- scan range (if you want to measure a larger distance then you need to wait longer for the sound to come back)
- motor speed
- ping transmit duration (to a minor degree)
- processing time
- communication rate
I had a quick look at an MS1000 user guide and it discusses being able to set ‘scan speed’, so presumably this is an attempt on their part to make the control more intuitive or something. Perhaps it’s easier to remember for non-technical users that ‘slower looks better’, whereas our focus is more closely linked to what you’re actually asking/commanding the device to do (‘give me finer resolution’), which has a side-effect that the scan is slower (in the same way that ‘increase the scan range’ makes it slower)
We learn the terminology on the disciplines we work with. Between commercial survey work and SAR work I have learned that vernacular. The Blue ROV will be used for SAR work, mostly body recoveries, in tandem with the Mesotech. Being able to cleanly image the victim is my goal. Your gradian 1 looks to be what I need. For a better idea of what is going on in the SAR world go to this page. (1) The Technical SAR Side Scan Sonar Group | Facebook This is a private page and we post images for other teams to learn from our experience. I have posted 2 long reports on difficult searches from last year. Your vehicle is gaining favor and this would be a great opportunity for you to learn what we need and how we use it. A tool is only as good as it’s operator. The operator has to know the discipline or the tool won’t be of solid use. Applications differ and I think this will expose you to a world out there that has been waiting for this product. Matching the needs will be a win for both.
Thought people might like to see for context, this is one of the first scanning sonars I had to deal with way back when Mesotech started, (I think Bob made this in his garage!!!) -its a 961 mesotech that had a HUGE black box controller (which I still have somewhere!) - its resolution was pretty appalling compared to anything modern but it was a huge step forwards then compared to the amatech that was about!
for size comparison its sitting beside a ping in its cardboard box, the ping is way better that this was but obviously 40 odd years have passed and the new mesotechs like mentioned above are a different ball game again - the 961 cost roughly the equivalent of a small house back then, the new mesotech I suppose the equivalent of a small car these days, and the ping the price of a small scooter maybe? - how technology moves on eh!
Nice. That thing is huge!