Very interesting - I was able to test it in real life and am impressed. In order to export the data from pix4Dcatch, I definitely need a pix4D subscription. Otherwise I can't get the photos (and of course no other data either). So if I only need the images for my own photogrammetry, what is the minimum variant of a Pix4D subscription to enable export? I would like to then combine the images recorded using Pix4Dcatch, the Emlid Reach RX and the iPhone 15 on the handle (I already have all of this) using corrected NTRIP provider data in combination with data from the RTK drone to process everything in Metashape. Is there any experience with whether and how the combination works?
You would need a Pix4D catch pro license (e38surveysolutions.com/collections/pix4d-emlid-scanning-kit/products/pix4dcatch-professional?variant=44997615354083) to enable export. That will also be necessary to connect to your RX or use the AR tools within the app. We haven't tried combining everything in Metashape, we're still in testing to learn the ins and outs of doing this with the Pix4D software.
Right now this kit only works with the RX, catch does use multiple sensors from the iPhone in addition to the RX for the positional data of the pictures.
@@e38surveysolutions59 Thank you for the reply. PIX4D claims that a base station is not needed for GPS denied areas (under a bridge or close to a building) while using Catch based on the “tracking and inside geofusion” (their words from a video). Do you find this claim to be accurate?
@@robertobey9415 I imagine it is not quite black and white and that there could be accuracy degradation depending on how much area you were covering while GPS denied. You may need control in some GPS denied areas to tighten up your accuracy.
No, the offsets that are important are measured from the RX to the camera lens of the phone. If you're using this kit with the SPC+ case on your phone you can select SPC+ for the pre-configured values for those offsets.
@@e38surveysolutions59 Okay thanks. Interesting that the viDoc uses a laser plummet to determine the distance to ground, but no distance to ground data is needed in this case.
At 2:30, you show a map of the surveyed track/path, with yellow indicating reduced accuracy. Can the images/LiDAR points collected with reduced accuracy be filtered out and collected again?
Yes you could do that, however processing in Pix4D cloud or Pix4Dmatic should allow you to clean up your data as necessary. As of now we're not sure exactly how Pix4D implements the LiDAR data in conjunction with the photogrammetry processes that they're applying to the dataset, but hopefully we'll have some clarification on that soon.
Accuracy in RTK/GNSS under canopy? 5 meters is the best what you are hoping for. I do not think that PDOP of under 1.0 is real when you are close to a building, so i am not trusting this values from Emlid
@@furiou3 I see hdop and vdop, which both seem pretty low, but I don't often look at those values, typically I just look at pdop too. Is there some way you calculated a pdop lower than 1.0 with the given information? Or did I just miss the part where there was a pdop given? If it is an issue, it's likely not an issue in terms of what Emlid is reading, but some sort of issue when it is reported/interpreted by catch. I'm sure they will just update the app in that case and it will show properly.
We haven't run any head-to-heads in terms of data quality. One functional difference is that we can unscrew the RX, put it on a rod and run it with Emlid Flow or Flow +Survey, or even MicroSurvey FieldGenius for Android if we need a fully featured data survey software.
