I’m thinking to buy dji p4p v2 but ı dont know reach m+ compatible with p4p v2
It should be. Depending on how you are integrating the camera is the same, but also the Emlid kit can be a standalone GPS system.
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Yes, if referring to LEDs flashing when camera takes picture thereby driving down timemark pin on the Reach M+.
Don’t get the v2+ as it wont allow you to load third party apps to automate flights which makes useless for mapping.
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Hi @erdemcankur12,
It is not an easy task to integrate Reach M+ with DJI drones, as their cameras don’t have a hot-shoe adapter.
As an alternative, I would recommend using 2 Reach RS+ to set ground control points.
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RTK is possible, but as you said, not an easy task. PPK is extremely easy and some GCP’s should be used regardless of the solution.
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I have leica gps right now. then I should buy phantom 4 pro v1. for reach m+. I will buy just v2 not v2+, is there a problem for v2? dronedeploy and pix4d supported p4p v2. And I will use for cam Tuffwing - Phantom Emlid Reach PPK Integration Kit
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My setup as well including DroneDeploy, but we use Topcon. 
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The “black box” of the Phantom 4 records the exact moment (including milliseconds) in which each picture is taken. It is therefore possible to extract these data and associate each photo with the exact position obtained from the M+.
All this “in theory”.
Unfortunately, “in practice” this solution only works if the drone stops for several seconds at each trigger point (killing the battery) because if the drone is in flight there are so many micro-errors that make the system unreliable.
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I wouldn’t call a few cm absolute accuracy from such a system unreliable…
That would be a completely new logic on the drone so it’s really not feasible from a data standpoint. You can’t even maintain that the time is sync’d between the drone and M+. This is basically what Vanavara is trying to do with all their hardware and I have a feeling that by the time they are done it’s basically going to be at the same point as the other Phantom 4 upgrade providers except that it will be publicly available for DIY’ers. How much is your time worth? Mine tells me I should just go buy a P4RTK - if I was interested in that sort of thing. #nodronertk
I agree.
And if the Phantom 4 RTK were able to totally eliminate the GCPs (at least to the relative precision) I would have already bought it… unfortunately in reality it is not so…
I’m assuming you’ve tested the P4 RTK. What did your tests reveal?
As for GCPs, what they are used for in your processing, and what tests and results would give you the confidence to eliminate them? If it’s a test i can incorporate into one of my flights I can see if our Frankenstein P4A with M+ and vanvara ashot would pass.
I haven’t personally tested the Phantom 4 RTK.
Unfortunately, when you perform a professional topographic survey, you must be absolutely sure that the measurements are right. If they are not, your customers may have a lot of problems and lose a lot of money.
I believe that the GCPs give this security and that today it is irreplaceable. You always need a sort of double check.
Even if you had 3-5 cm rmse from the images aloneYou would still need GCP’s as checkpoints, to verify your result. With PPK on the drone, things are still relative. You need something to drive home the absolutes without a shadow of a doubt.
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datum adoption and model verification can be done on bare earth, well textured hard ground, etc. but i keep seeing people refer to GCPs specifically. i can’t tell if this is being used interchangeably with ‘check point’. I agree with the need to check your work, but this almost goes without saying.
but i’m still trying to figure out what people mean when they talk about the possibility of eliminating ground control. because i could conceive of myself flying a mission, adopting an RL on a spot of are earth, and being confident of passing checks elsewhere on the model without having a single, artificial GCP anywhere on-site. I can conceive of this process possibly being better than adopting a marked GCP, because locating markers as ray intersections is not necessarily the exact same process by which the ground is reconstructed via depth maps.
are you guys using GCP synonymously with ‘check point’?
without PPK, GCPs are needed to control the model, to allow the camera paramters to be fit to reality to minimise the doming or bowl-ing of the model. and to add scale. in this respect, as distinct from ‘check points’, GCPs are not needed on a PPK flight.
GCP’s are needed for alignment to local grids. This does not apply to surveys unless they are using local elevations or are surveys that are intended for a construction process. In construction and drones the surveying is done on a calculated grid system derived from other systems and situated appropriately on the subject parcel. If GCP’s are not used you will not align in X,Y or Z to the design and therefore your affect on the construction process is limited to a small percentage of the current capabilities and future possibilities.
For me, yes. GCP’s (checks or controls alike) are equal to manual work (getting to the GCP location, setting up GNSS or prism on point, waiting on data-gathering, remove instruments and GCP target itself).
So the fewer GCP’s needed, the less work it is.
Yes Sir! Everyone’s goal is to get rid of gcps, but it’s not going to happen for the reasons I mentioned above. This is where the PPK comes in. I have been able to go from 15-20 points on 100 acres to 7-8 depending upon the shape.on top of that, the accuracies have increased by about 20-25%. Truth is that my end goal is to only have 4 gcps. If you look at localization theory this is what you need to truly nail down an area.
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thanks for everything. It’s nice to have low sensitivity, but it varies depending on what we use for. I’m working on the railroad project. Quick and easy solution for the field analysis of the water basin design process.
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