The SF11/C laser altimeter - awesome performance for $249

With a range in excess of 100m and able to measure over water, the SF11/C is the most cost effective laser altimeter for drones on the market today. Compatibility with Pixhawk and derivative flight controllers and its multiple interfaces including serial, I2C, analog and USB make the SF11/C the easiest plug-and-play solution for altitude holding, terrain following and safe landing.

The SF11/C was developed to handle the unpredictable real-world conditions that sensors face when attached to a drone. Environmental factors including vibration, wind, noise, temperature fluctuations and extreme contrasts in lighting from brilliant sunshine to pitch dark are all managed by the SF11/C, and whilst all this is going on, the SF11/C measures to rapidly changing terrain, giving stable results over wet and dry surfaces without producing false readings.

Tests conducted by the Center for Research into Ecological and Environmental Modeling at the University of St Andrews in Scotland demonstrated the abilities of the SF11/C over wetlands and open water. Their requirement for consistent results under these difficult conditions were easily met by the SF11/C, contributing to important conservation work.

An important characteristic of the SF11/C is its long measuring range. This is especially useful during changes of roll or pitch angle. Data from the IMU is used to correct for geometric effects during such maneuvers, but this only works correctly when there is valid measurement data from the laser. The long measuring range of the SF11/C makes this possible as you can see from the graph below.

The green line is the roll angle, the purple line is the barometric height referenced to sea level and the red line is the uncorrected, AGL altitude from the SF11/C. During tight turns the measured distance increases significantly but the long range capability of the SF11/C keeps the ground clearly in view. 

 

More details about the SF11/C can be downloaded from the website. The SF11/C is manufactured by LightWare Optoelectronics (Pty) Ltd based in South Africa. LightWare has been designing and manufacturing laser altimeters for the drone market for 5 years and is committed to providing high quality products to the industry. The official distributors in the USA are Parallax and Acroname.

Special thanks go to the dev team for their contributions to the driver software and Tridge for his tireless and occasionally incendiary flight testing ;). 

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Comment by Jason Smoker on February 5, 2017 at 5:58pm

@laser Developer yeah it was bit extreme most i have done was 50trigger points to 100m.  I think 50 is more than enough.

Our average is around 20 to 30 in one flight. 

Comment by Laser Developer on February 5, 2017 at 10:24pm

@Jason - so would these trigger points be totally independent values or could they be entered at equal spacing? I'm just trying to imagine the setup process - it would be tedious to type in 50 values and easy to makes mistakes.

Comment by Jason Smoker on February 5, 2017 at 10:59pm

most of the time they are equal spacing.  But unfortunately not always it depends on our client needs.

yeah it would be tedious job but to have trigger it at the correct height they would be no arguing at the height of the picture taken

our next job for example is 13F story building not so high but they want each floor taken.  At the moment i have to fly slow enough for my cameraman to shoot at height.  But if I have it pre-set it doesnt matter how fast i go because it would trigger the shutter.  I guess it would take around 5mins to type in the heights?

Comment by Laser Developer on February 5, 2017 at 11:14pm

OK. A nice graphical interface would be useful. Do you have building plans or something that you use to get the reference heights?

Comment by Jason Smoker on February 5, 2017 at 11:21pm

YES!! we normally get the plans of the building we shoot a couple days in advance. which reference what height to shoot at, then we make a excel spreadsheet to cross reference the plans of the building.  then hang it in front of my cameraman

Comment by Jason Smoker on June 27, 2017 at 7:29pm

@laser Developer any more thoughts on my idea? possible to get upgrade?

Comment by Laser Developer on June 29, 2017 at 1:44am

@Jason - We're looking into providing an in-field software upgrade feature that will make it much easier for you to test and validate the additional software features. Please give us another month to work on this :).

Comment by Jason Smoker on June 29, 2017 at 5:26pm

@laser developer sounds great.

thanks

Comment by Jason Smoker on September 3, 2017 at 9:28pm

@laser developer any news?

Comment by Tom in NOVA on March 12, 2018 at 7:53pm

I have an SF11/C (120m) rangefinder/altimeter with firmware Version 1.1.     Does it need to be updated?   I noticed mention of Version 1.21 in the manual , but cannot find any instructions/download.

 

Thank you,

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