Servers by jDrones

Mapping a lake with ArduPilot


(Olav Aamaas) #41

Did not find a topic to post suggestions for cheap transducer solutions. But here we go… Options are wider with NMEA 2000 than 0183. But alternatives do exist:

Garmin intelliducer: 170-230 USD on Two versions: Transom mount, Thruhull mount. The thruhull mount can be acquired in nmea 0183 and 2000, transom mount is 2000 only. Note: Verions for two different hull angles also exist.
This smart transducer has been implemented before by ardupilot enthusiasts (using Arduino and radio comm). Solution is simpler than mine, pinout available here:

Airmar P79
Also available in NMEA 0183 and 2000. Adapts to hull angles up to 22 degrees. 7 degrees beam width. Min debth 0.5m. 1 data update rate per sec. The Airmar P39 transom mount has similar specs, but a wider a wider beam of 15 degrees. P79 measures depth only, the P39 also temp and speed.
Available with various cables (like for Garmin) and in various prices (150-300 USD) on Amazon and elsewhere (typically around 240 USD)

(Odilon) #42

Randy i sent you an menssage in facebook menssager, please reply the menssage, i’m looking forward to you reply.
And congrats mate, it’s really cool what you did!

(stevenette) #43

Hi Randy!

I have been swamped by other projects once again, but have time now to continue my work on this project.

The sonar I have is from airmar and works on NMEA 0183. I have hooked it up to an arduino with a GPS and it logs fine, standard output of $SDDBT. Now if I can only get it to work on the ardupilot, I can continue!

It outputs +/- 3.3V at 4800 Baud, which I think the ECT sonar outputs +/-3.3V as well. If not, then I need to convert it somehow. For reference I have a blue and white tx/rx wire hooked up to pins 2 and 3 of the sparkfun serial shield thing, with the rest following the procedure on mission planner tutorials.

Still testing, will let you know if I ever get it to work! Cheers

(rmackay9) #44

@stevenette, great! If it’s NMEA 0183 it should work.

Once you get it working I’d like to add it to the wiki. I guess you’ve got one of the sensors listed on this page?.

(stevenette) #45

Yes exactly. Also, I finally got it working for the first time about 10 minutes ago! I have an entire box of serial converters and voltage dividers and finally figured it all out! Turns out I need to put the sonar in water to output a proper signal.

I can get all the details together once I have everything working again. For now I am having a hell of a time trying to use my frysky transmitter to work in manual mode. The programming of these transmitters is beyond me at the moment. Also on the 5th generation of my boat I think? Balsa with reinforced fiberglass was a bad and time consuming choice.

Also, Matlab and R are terrible choices for mapping. Their bathymetry libraries are utter garbage if you are not using perfectly spaced points in lat and long. Might have to finally suck it up and pay $200 for reefmaster.

(rmackay9) #46

Great thanks for the info.

I’ve also been thinking about what desktop tools we should recommend for viewing mapping data. Over the summer I hope/expect that @peterbarker and I will complete the driver for the echologger MRS900 scanning lidar which will provide 2D which light allow much more detailed 3D maps of the bottom. I’m not sure how well ReefMaster can visualise a really detailed 3D Map.

(Kevin Klemens) #47

@rmackay9 For data visualization, I recommend having an easy way of creating an XYZ (Lat, Long, Depth) .csv or .txt file from the dataflash logs. If there is a quick way of extracting just those values, I may have missed it in the wiki.

A .csv file could then be easily imported into Reefmaster, my favorite for making quick bathymetric maps, or into ArcGIS, the standard for professional map making and analysis. A copy of ArcGIS for personal use is like $100 per year.

Blue Robotics will be coming out with our own single beam sonar next week, that will be more affordable than the Echologger. If there is a quick way of creating XYZ.csv files, I would like to create a guide reference in our “Learn” section to assist people working on USVs and data collection and have importing instructions for Reefmaster and ArcGIS.

(Kenny Trussell) #48

@Kevin_K, does what Michael Oborne showed Randy in post 7 (Mapping a lake with ArduPilot) accomplish the xyz export you desire? It may only export one field at a time. I haven’t tried.

(rmackay9) #49


Great, thanks for the info! I’m really looking forward to seeing/trying the BlueRobotics sonar.

As @ktrussell says, the export can be done in MP by click on the column headers and then filtering for only the DPTH message.

Peter’s work with the scanning sonar though will involve a companion computer (maybe an RPI3 or RPI zero) running APSync and we plan to create a separate output file that makes it easy to upload into something like ArcGIS or ReefMaster. This is actually why I brought this up - we’re wondering what the format of that file should be. At the moment I suspect it will be a .csv file with lat, lon, alt (?), roll, pitch, yaw, depth… but the scanning sonar will produce a lot of data and we may end up with a single line per point… this is a bit wasteful but perhaps the easiest for ArcGIS to upload?

(Kevin Klemens) #50


The Ping Sonar is out! Looking forward to see what you do with it!

Interesting thoughts on the scanning sonar. Mechanically scanning sonars are typically not used for bathymetric mapping because the mechanical scanning is relatively slow to rotate around. These scanning sonars are good for navigation and obtaining acoustic imagery on ROVs, but fairly limited for surface vehicles.

The industry standard for sonar scans is .XTF, but those aren’t read easily by non-sonar programs. ArcGIS chokes and I don’t think Reefmaster has that import functionality. ArcGIS would prefer a type of raster or a GeoTIFF.

I do not remember what Echologger uses as their recording format, it may be a closed format.

I think the only file format type common between the two would be an XYZ text file.

I think what you want for wide swath bathymetric data collection is an entry level multibeam sonar…but none currently exist.

(rmackay9) #51

Great, thanks for the info. A person at also implied that the mechanical sonar may not be great for bathymetric mapping… I think we will just try and see how far we can get and hopefully it’ll be useful for something and if not then at least it will be a basis for integrating something better in the future.

Really looking forward to the blue robotics Ping sonar!

(Kenny Trussell) #52

@rmackay9 (or others) I have a need to build or buy a sonar mapping boat similar to what you show here. I am willing to buy the boat if a good one exists, but the boogie board version looks pretty good. Several months have past since you first posted this. I was wondering if I were to build a similar boat today, what would be the best parts to buy as far as the boat, thrusters and sonar? Would you change anything? I looked at the EAMS Lab site and do not see a boogie board based boat. I left an inquiry.

(rmackay9) #53


Well, somewhat coincidentally I’m just about to start assembling two more for a Japan mapping project called DeSet (web page, video-with-over-the-top-music) and I’d be happy to send you some parts (carbon fibre plates, electronics box, screws) to make it easier to assemble if you like. I think you’re more mechanically savy than I am so you might have some good advice for improving it.

I’ve changed the design a bit from the original by:

  • adding herelink for telemetry and video
  • HolyBro BLHeli ESCs with telemetry feedback (I think it’s these)
  • larger battery (7500mAh) which I hope will give a bit over 1hr of drive time
  • larger electronics box (20cm x 30cm) with latches instead of the 17x25cm with screws of the original
  • different carbon fibre boards to connect the waterproof box and thrusters to the boogie board

I would really like to add standoffs between the boogie board frame and the thrusters to help avoid floating sticks and leaves from getting caught in the props… but I haven’t figured out how to get these made yet.

I also haven’t figured out how I’m going to cut all the required holes perfectly vertically through the boogie board because it won’t fit under a drill press.

(Kenny Trussell) #54

@rmackay9, The DeSet project looks like a good challenge. I’m sure you are up to it if anyone is! The project I have in mind is for my company but is experimental. We have ponds we sound on occasion manually with a person in a boat. I would like to try to automate the process. I have a little bit of a budget, so I hope I can buy relatively good quality parts and also pay you for any parts and shipping that I cannot source more easily locally. I will PM you my information.

(David Boulanger) #55

I’m jealous of the Herelink. I’ve done a bit of pond bathymetric surveys with an inexpensive Lowrance Elite 4 system and a survey grid on Mission Planner. The Ping Sonar looks like an affordable substitute with the possibility of viewing depths live ( I think ).

(Pau G.) #56

Hi Olav,

Congratulations for this input.
Do you think that is possible to connect the DST-2 to the Lowrance Totalscan transducer? It also runs 200Khz. But the connector is 9 pins.
Thanks so much.

(Olav Aamaas) #57

I would think you should be able to make it work. The totalscan supports multiple frequencies, does sidescan and downscan. And chirp right? The DST200 will of course only drive it at 200kHz.

To make it work you need to figure out how the pins are wired. I had a quick look around for a wiring diagram with no direct hit. But when I think back, neither had I. I studied some Airmar pinouts and made my best guesses.

The source I used is probably still valid:
One problem (challenge) though: It is stated as a listing of non-chirp transducers. But it does include transducers with 9 pins.

I had hoped to find the answer here instead:
But, as the introduction reveals, you will probably not find 9 pins answers here. Did not search extensively, though. And only had my cell phone at hand.

My best bet is to start to look into the Airmar 9 pins alternatives. Lowrance (intentionally, I assume) does not document the wiring at all. So you will have to experiment. Or try to find answers by a more thorough search :slight_smile:

(Kenny Trussell) #58

For an initial low-cost 1st prototype, would do you more experienced folks think the HST-WSBL and DST-2 shown here could be worthwhile? The transducer is $58.57 at the Lowrance link on that page.

Transducer Options
(rmackay9) #59

I don’t qualify as one of the “more experienced folks” but I had been thinking to try the analog sonar because it’s so cheap and apparently has a long range… so if you do try it I very much look forward to hearing how it goes!

(Kenny Trussell) #60

I will do that then. I wish the digitizer was cheaper. A $200 digitizer offsets the cheap transducer! But, it is what it is, I guess.