The reason I ask is I’m usually working in pretty remote areas, but setting checkpoints would be very useful. As for flying, the single frequency flys the drone just fine. Any disadvantage to just logging and doing PPK after?
I don’t use any UAV’s or perform photogrammetry but Michael Lambert (https://community.emlid.com/u/chascoadminor) or Christian Grüner (Profile - wizprod - Emlid Community Forum) here on the forum are the leading experts concerning PPK in aerial imaging. Emlid support is also very knowledgeable.
From what I’ve read and talked with others about this topic, PPK is the methodology to use.
So, only a hand-full of drones currently support tagging RTK tagging of imaging. It is difficult because you need to own the entire ecosystem for this to be possible. There is an inherent delay in the processing and so on, so if you compare the time of trigger to the time of position, they will be offset.
So, you need to take that into account, and the. Add the position data “later” instead…
you can’t do that with a normal camera, where the drone doesn’t communicate on an advanced level with the camera.
So, the only advantage of using RTK is then positioning. But that of course requires that the drone gets the GNSS data from the M2.
The only disadvantages of PPK are the added time and effort that goes into the post processing.
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Hi Shaun,
I’ll add a few words about the specificity of our products.
When we talk about mapping, we usually talk about PPK. Our modules Reach M+ and Reach M2 can register precise time marks but can’t edit images metadata. So, even if Reach has a Fix during a flight, you still need PPK to obtain precise coordinates for images.
From my perspective, PPK mapping is still the main way to do mapping. But, as Christian noticed, RTK drones have entered the market. But I didn’t meet models which accept GNSS data from 3rd-party modules. They usually have their own inside. They can receive corrections from our devices, but that’s another story 
Even with RTK drones, there is a need for post-processing sometimes. So, PPK is a good way.
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The only hiccup in PPK is a good solution to consistently retag the images. That said what you are looking for with PPK is repeatable relative accuracy. No matter what method you are using to collect data you better have at least 2, preferably 3 checkpoints. This means that the antenna height is unimportant. You can put it in there but you still have to check the backend data against your checkpoints. We fly two different kinds of drones and in order to keep everything easy we do no offsetting of the data. Everything is processed and then aligned with the control points and/or GCP’s. This also overcomes any issues that may arises from CAD files being configured differently. Scale factors (or not) and random shifts or rotations are not uncommon. They are definitely better than they were 10 years ago but it’s still one more check that needs to be made EVERY time.
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