Hi there everyone!
I'm really quite new to this, all of this. In fact, this is my first post.
I first became interested in this project entirely by chance; I happened upon it while looking for small aircraft that can be used in aerial surveys. I've noticed a few other users have a fair amount of interest in the same topic.
Ultimately I will end up building a drone to capture aerial imagery and use the software I normally use when doing a standard aerial survey (with a much larger Cessna) to produce a DTM. But there are a few things that are still up in the air (...nice pun...) - Life will be so much easier if the IMU could export the inertial measurements at the exact time that the camera takes a photo - is this possible? And to what sort of accuracy?
I know that this is not a prerequisite, but in practice, having your external orientation already computed - in the form of photo ID; x; y; z; omega; phi; kappa - is a real time saver. Rather than manually finding tie-points (because the computer is just hopeless at the task) and having to take ground control.
With the IMU capable of spitting out these readings, a quick survey of an area can be done at low cost with a quick turnaround time. Perfect for disaster relief and the like.
Has anyone had some experience with this? What are the IMU reading like with the ArduPilot?
If you have access to a linux box or cygwin environment on windows you can use exiftool to geotag the images with great results. I posted a bunch of different how-to for doing this here: http://dronemapper.com/faq
There is a great reference and more detail w/ exiftool here: http://www.sno.phy.queensu.ca/~phil/exiftool/geotag.html
The basic idea is to use the .gpx file that is exported from APM or generate your own .gpx file from a flight controller log, next you can use this .gpx file to geotag each image. You don't have to mess with your internal clock as you can provide command line options to time offset, etc. Hope that helps.. Cheers
Look also this blog:
Thanks! Will have a look at both!