New UAV regulations in place and active

The new UAV regulations are now active in Germany! For commerical and research flights things are more simple now for copters below 2kg. There is now a general allowance in place for the full federal region of Germany for UAVs below 2 kg (with the restricted regions as listed in the regulations). For copters with more weight a specific training certificate is needed and up from 5kg you need an allowance of the regional  aeronautical authority.


Speeding up Agisoft Photoscan

For some of the copter data processing folks Agisoft Photoscan turns out to be the most important tool to calculate point clouds, orthoimages and nadir data mosaics. Problem: very long processing times with dense point cloud calculations with high or ultra-high settings (full resolution image matching with SfM (Structure from Motion) algorithms).

Some nice net finds show how multicore processing has its limits and why you should invest into GPU performance … and in high end 3D graphic hardware.

Combining more than 20 CPU cores doesnt seem to speed up the process and combining more than 4 GPU systems also doesnt seem to help. There is only a minimal speed increase when you add more CPUs and/or more GPUs when a 24 core system is already installed.

It boils down to a dedicated system with 2-4 Graphic cards with 3D acceleration (GTX-1080ti cards from Nvidea), with approx 64-128 GB RAM and a dual i7 system setup.

mtk – Sören


MicroSD cards and standards …

There is a lot of confusion about the speed of MicroSD cards these days and various standards exist. Overall its easy to buy yourself into the wrong card type and for copter data acquisitions with the P4Pro the card speed is essential.

So here we go:

UHS-I and UHS-II (Ultra High Speed Classes):

UHS-II is the newest standard but is not supported by many yet. The Phantom series 3 and 4 all need UHS-I and definitely the fastest UHS-I cards. The UHS-I bus goes to 104MB/s whereas the UHS-II bus goes up to 300MB/s  (theoretical limits – the cards will not perform at this speed).

u1-u3 Rating:

UHS Speed classes are subdivided in to u1 and u3, while u3 performs minimum at 30MB/s write speed (needed for copter flights).

Video Rating: 

A new speed rating is called “video rating”. It scales from V6 to V90. The fastest cards are v60 right now (possible values are V6 V10 V30 V60 V90, but note that V60 and higher is usually UHS-II bus type and not supported by Phantom 3 and 4 series).

C-Rating (c1-c10)

Speed Rating up to 10MB/s write – this is a slow class rating and c10 should be always possible for fast cards.


Up to 32GB capacity the cards have the label microSDHC whereas cards bigger (64-256GB) hold the label microSDXC.

For the Phantom3A (5MB/s max write speed) Phantom3Pro (60mb/s =7.5MB/s) and Phantom 4Pro (100mb/s=12.5 MB/s) series the fastest at writing to card seems to be right now the UHS-I SanDisk Extrem plus and Extreme pro cards (90MB/s sequential write). While this seems overkill the u3/V30 just certifies that you will never be below 30MB/s write speed under real world / all temperature conditions.

  • SanDisk Extreme PLUS  microSDXC UHS-I u3 V30
  • SanDisk Extreme PRO microSDXC UHS-I u3 V30

Nice summary from Wikipedia goes here:




Using DroneDeploy and the POI mode for automatic point cloud mapping

Using DroneDeploy and the POI mode of DJI.

Have been doing some leaf-off flights now in March on one of my favorite sites for complex tree crown point cloud mapping. To add to the leaf-on data from last autumn.


Fig.: Leaf-Off point cloud with combined height color coding and reflectance color coding.

This time I also checked the full automatic flight modi using the POI (Point Of Interest) mode from DJI and Drone Deploy with the P4Pro and the P3A.

Both work perfectly although I believe the POI mode can be dangerous when its done with low altitudes. You have to carefully check that the radius is free from obstacles when you define the center position, altitude and distance from center (radius) for the POI flight. When POI is started it begins with comparably low speeds. You can modify the speed setting when the POI mode started. Unfortunately you cannot modify this stetting before you start. Tuning the speed on an iPad or (even more difficult – on an iPhone) is kind of dangerous because you easily move the slide too much to higher speeds than wanted and the copter will immediately accelerate and start circling your POI object like crazy until you managed to move the slider to slower speeds. There is however always this stop button to kill the POI mode – this is handy and needed sometimes. When you press the stop button the copter stops the POI mode completely and waits for new commands.

Continue reading “Using DroneDeploy and the POI mode for automatic point cloud mapping”

“Drohnenverordnung” in the Federal Council

Regulations to fly copters  the “Drohnenverordnung” went through the Federal Council – the 100m regulation will be redone. Overall good news for those of us who fly for research or commerical projects. The ascent permission for copters below 2kg/5kg  was skipped. This will make it much easier to fly within legal regulations.


Phantom 4 Pro – lens flare issues

Some more tests with the Phantom 4 Pro: one major “issue” with this system for stills / photography is imo clearly the flare sensitivity of the lens/sensor combination. The into the sun shots just capture a lot of flare and the sun star is very much Samyang 14mm like. This is an issue and it reduces the image acuity for 3D point cloud modeling for object measurements as well as for the landscape panorama approach.

The against the light shots look very much like the Samyang/Rokinon  14mm lens character. The sunstar has light rays that increase in size from the center and these rays cover the full frame of the 1inch sensor when the illumination comes from one of the outer edges. It clearly degrades the full image when the lens is stopped down to f.e. f8 but gets better when the lens is driven wide open. There seem to be some diffraction effects at work that are clearly not so great. You can drive the camera to generate sharp sun stars, but as usual here the characteristics of this star make a difference to some of us.  The Samyang like star is not so well received. The linked flare issue is much more a problem because it is hard to avoid when you have the sun in your frame. For some scenarios a lens hood may be useful but its only functional for those shooting scenarios where the sun is not within your FoV.

To be honest I am bit puzzled … this is the first affordable 1inch sensor platform with nice resolution and better DR, but – the flare issue is likely killing some of the potential ideas that you might develop with this machine.

Some examples:

smh-lim15-20170214-d4c5abaf23a147c434e47d2a0105ac83-0281 smh-lim15-20170214-d4c5abaf23a147c434e47d2a0105ac83-0300 smh-lim15-20170214-d4c5abaf23a147c434e47d2a0105ac83-0304

@f4 things get a bit better, but with this image below also the light levels have changed:

smh-lim15-20170214-d4c5abaf23a147c434e47d2a0105ac83-0366 smh-lim15-20170214-d4c5abaf23a147c434e47d2a0105ac83-0424 smh-lim15-20170214-d4c5abaf23a147c434e47d2a0105ac83-0447

Comparison shot done with the Phantom 3A, clearly shows that the lens/sensor combi wont give the same amount of flare here (again different light level and different sun illumination angle):


mtk, Sören

Drohnenverordnung doch noch auf der Kippe?

Der Modellfliegerverband hofft auf ein Veto im Bundesrat. In erster Linie geht es um Ausnahmen für die 100m Flughöhenbegrenzung in der neuen Verordnung.


Mal sehen wie sich das entwickelt, auf jeden Fall ist AE freie Variante in der neuen Verordnung für die wiss. und kommerziellen Flüge für viele eine Erleichterung, da die regelmäßige Beantragg. wegfallen würde.

Die Flughöhenbegrenzung von 100m ist zwar zT. problematisch – in vielen Fällen jedoch sind 100m ausreichend für die kommerziellen und wiss. Bildflüge. Die Segelflieger haben allerdings ganz klar andere Flughöhenbedürfnisse!

Für die automatische Kartierung von größeren Flächen wären die größeren Flughöhen natürlich auch für wissenschaftliche Anwendungen sehr interessant, allerdings steht hier soundso das Fliegen in Sichtweite im Konflikt. Hier sind allerdings auch Ausnahmegenehmigungen möglich in der neuen Verordng.




New Regulations for Copter Flying

Some new regulations seem to become standard now:

Dobrindts Flyer:
Likely difficult to check all those that are already flying.