Starting from scratch, with the view of eventually flying multispec cameras over farms back home.

Hi all,

I have been silently watching this group for months now and reading as much as I can and I am finally at a point where I would like to ask for input.

I live in South Korea and at the moment UAVs are just a hobby, but like many of you I would like to be a part of this massive evolution in tech and its endless Agri applications. My dream would be to fly UAVs over farms in South Africa (my home) and collect crop/stock data confidently and possibly offer this skill set to the Environmental sector too, as this is where I have most of my training (EIA and ESIA studies)

I have just finished building a pretty solid flying wing and I have got the hang of flying it: 

My question is: What now?

Do I buy the APM autopilot system and learn how that works? Do I get setup for FPV? Cash in my life savings and buy a decent multispec cam? 

Any suggestions would be most welcome and additional tips and wisdom would be appreciated.


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In my opinion, the next step is an autopilot that can fly waypoints (gps) and a gopro or point and shoot camera. After that, you may want to add an FPV video downlink, however, we have flown for years without this option. Look into NDVI conversions for point and shoot cams. As an inexpensive imaging system for vegetation. You have reached the crossroads where the data package becomes mission dependant. It sounds like you will need to be familiar with several systems as your missions will all demand different setups.

I suggest getting one of multispectral webcams and some kind of ARM board to build your multispectral cam next. 59.95 for the multispectral webcam :)


ps I am kind of in the same research phase...

Hi Dale,

Buy the ready to fly Skywalker 2013 with PixHawk autopilot, which are for sale on the 3DR store, no need for the FPV option, but add the FrSky Taranis option (in my opinion).

Then get hold of two Canon cameras that will fit like the s95 model and covert one to 720nm, download the CHDK (Canon Hack Development Kit) and "Card tricks" ftp program which you then use to upload the CHDK script onto the SD Cards, so CHDK boots when you turn on the cameras. CHDK is now well supported by Ardupilot and Mission Planner, the cameras can be triggered using a micro USB cable connected to the Ardupilot, subscribe to the Photo Mapping group to find out more about this.

Using 720nm and the Red Channel from the uncoverted camera you can create NDVI images, you will also have standard RGB images to create mosaics for visual crop recognition, 3D Digital Elevation Models etc.

You will need some software like AgPixel, PhotoScan and a GIS program like Global Mapper, all are available for trial use before you have to part with any cash.

Once your making some money then decide if you want to buy a $3,500 multispectral camera, etc.

Here are some images I took of wheat crop trials from 100m Above Ground Level, a couple of years ago with a pair of Canon s90 12.1 mega pixel cameras running the CHDK script. They have been re-sizzed for the web, the originals are 3MB each.

The bushy plots are wheat varieties that have "logged" - collapsed under the weight of the rain and wind, the flat areas are crops that are still standing tall - vertical.

My trusty old Maja with twin cameras, RIP.

Wow thanks for that feedback Keith I will definitely look into the Skywalker and your suggested camera setup. How did you get the Red channel on the canon camera and how did you go about the 720nm upgrade?

Hi Dale,

I will let you into a trade secret; Advanced Camera Services from Cambridgshire in the UK, converted my s90 camera to 720nm for around £120 ($180) two years ago, ACS you can email them using; or you can do this yourself and there are many videos online, which show you how to do this, but for me the £100 was worth it, as you can damage the CCD or other parts and ACS cover that cost, if it happens? You can buy the cameras secondhand to save some money, search on eBay or a similar web site.

Make sure the cameras you choose have RAW imagery as a selection, you need to shoot in RAW format, so the Red channel can be slected to obtain NDVI, etc. AgPixel and other programs should be able to do this automatically after you upload the RAW image data sets. The Canon s90's I had allowed me to shoot in RAW + Jpeg, so you have visibe images as posted above and RAW images for processing into NDVI, etc.

One note of caution, you need failry big SD cards, as the RAW images are 10MB each and the Jpeg 3 / 4 MB each, making 14MB per shot! Also when using CHDK, make sure the SD cards have a fast write speed of "class 4" or higher "class 10" is the best, there was also a limit on the size of 4GB to run CHDK, so you might want to check this out before buying the SD cards, as I have not used CHDK for over one year now. I am now using an IR trigger and Sony NEX7 camera. If the limit is still 4GB, then you will need a few sets of cards to save time in the field, as I prefer to keep the data on the cards and wipe the cards back in the office, once the data is safe on a server or desk top PC.

Hi Dale,

Just a quick update, check out this forum topic NDVI filters on DIY Drones, it seems the Canon s100 is now the best pocket camera with its own GPS and well written CHDK script, you can get the NDVI filters from the link above and make life easy for yourself.

Hi Keith,

why RAW format? Why should the red channel from a *.jpg image not be suited for calculating NDVI?

Kind regards,


Hi Keith

Do you think the skywalker will perform better than the Maja?

I'm looking to built one for mapping as well. now hunting for the best platform.

Hi Nik,

I have yet to try the Skywalker 2013, but I believe the PixHawk is a great AP and Skywalker has been used by people I know for FPV and they love it. The Maja comes in several parts for you to build, so if you're short of time or the skills to build it, buy the ready to fly Skywalker 2013 with RC Tx from 3DR.

Hi Dale

I'm based in the Cape and I'm busy working in the same area, primarily for the vineyards. There is a long and steep (and sometimes expensive) learning curve but there is a lot of good information right here at DIYdrones. Join this group and scan the contributions:

I can't add much to the great advice you've already been given here, but if you visit SA or return permanently at some point, look me up.

Hi John,

Great to hear from you are you a farmer? Glad to see that another South African is into this stuff :)

I will definitely drop you a line when I get back to SA.

Keep well

Wow thanks for all the info Keith! I will start putting together a list of all the things I need to start acquiring and will keep posting progress to the forum!

You have been super helpful!



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