Last year I was searching how to fly at safe low altitude to take the higher resolution photos that possible, to identify weeds and insects in crops and trying to know if a laser altimeter can do the task, first I bought a Lidar lite but looks unstable over rought terrain perhaps bad installed or configured and no more support to ask, but, in the way, Laserdeveloper offer me to test the SF11 and send me one, I was little nervous because I'm not have much electronic knowledge, I couldn't make Lidar work yet, and SF11 looks more professional with PC connection and configuration capable, but results an RTF tool, very easy to install, Pixhawk configuration I use as instructions said, I use serial connection and SF11 configuration I don't change nothing but have many things for different tasks, standard ones looks nice for me.

It have an intuitive software to test with the pc too, you plug to USB with provided cable, open the program and look readings, I them took a ruler and measured the SF11 with the floor and looks near perfect :O ; many rainy days them (I'm in winter :( ) I did a first little fly with strong wind, the wind hit the copter but altitude didn't change, a better day I can fly more to test and take this video flying over a rought terrain; I'm going to test over different crops with different stages, and different slopes to see what happend. 

Thank's to Laser developer to give me the opportunity to test this great altimeter :D

Now I test the SF11 over dry corn and, as Laserdeveloper explain here: the laser reads the floor instead dry plants so, no issues when little spaces between plants appears, wind isn't a complication too.
3 Nov: Now time to fly wheat, searching for insects and diseases, windy, as always, is present
It's curious to compare sonar altimeter with Baro
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  • saTxRxasis I hope is not possible to use with 3.2.1 Fw  but you can confirm here with devs

    Thank's Laser I enjoy high fly too so, when I finish testing, I drop the battery visiting the combine, that video part is not good because wind hits the camera and it's not possible to apreciate sf11 work but I'm going to share for you, it's short

    Fnoop, I hope there is a post discussion about that, if i found I share link. 

  • How reliable is this over water?

  • @Cala - More "real world" performance testing of the SF11/C showing some very important results. My favorite part is the high altitude test near the end ;).

  • Your quad really stay at low altitude, what a great success! I really adored with your work.

    So I assumed you use Pixhawk and I have silly question. Can I do the same with APM 2.6 on f/w 3.2.1? I know that this fc is obsolote but if it can't, what feature that naught in f/w 3.2.1 which can drive SF11?

  • Thank's Laser, to better explain how this tool works, at the begining I couldn't understand how can perform so well,  I expected that was going to jump up and down with every little leaf :O , as I have new videos I share here :D

    Nadia is who give me great support about the SF11, thank's Nadia.

  • Thank you Cala. Impressive low flight.

    @Robert, let us know if you need any assistance.

  • Wow! Very nice tests Cala, thank you. Seeing how the SF11 performs in real-world conditions is the best way for us to make improvements and advance the science of laser altimetry.

    For those people unfamiliar with lasers altimeters, you may be surprised to see how well the SF11 works over uneven surfaces and moving grass. This is a consequence of the physics that permits scattered reflections from steeply angled surfaces which is why our eyes are able to see these surfaces using scattered sunlight.

    The short wavelength of light ensures that most natural surfaces scatter light in all directions providing a very consistent signal back to the optical detector of the SF11. The rule of physics that is at work here is that any surface that has microscopic features that are larger than the wavelength being used will produce scattering. Since light has a very short wavelength, most surface meet this criteria, especially those of plants and soil.

    Another advantage of using laser light in agricultural applications is that the strength of the return signal is surprisingly high. This is because of the infra-red properties of chlorophyl that make plant matter reflective at the specific wavelength that the SF11 uses.

    For other non-contact technologies, the laws of physics make it very hard for them to work under these same conditions. For example, ultrasonic devices operate at a much longer wavelength (using sound) and the energy of their beam is easily deflected away by the flat surfaces of the leaves or simply absorbed by the sound dampening structure of the plant as a whole.

  • Nice, please share your experiences to see how it's work.

  • Cool, we will soon follow up with the same Lidar as an sweeping forward looking distance control unit.

  • Sorry, I confuse, this is the video with laser altimeter

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