Drone Remote Sensing and Mapping Discussion Board by Discussion Board https://padlet.com/University_College/5r9iy8w25bmx4okn General Discussion board en-us 2020-07-23 01:02:34 UTC 2025-09-09 20:09:08 UTC hello@padlet.com Hi Darren, experience is that Lidar and SfM are poor at picking up top heights, could this not be resolved by tilting the camera on a slight angle to pick up the larger surface area of the side angle of the tree top? https://padlet.com/University_College/5r9iy8w25bmx4okn/wish/951102821 Thanks, Ross]]> 2020-11-23 05:56:54 UTC https://padlet.com/University_College/5r9iy8w25bmx4okn/wish/951102821 https://padlet.com/University_College/5r9iy8w25bmx4okn/wish/1050382238 Hi Darren

I have a few questions;

  1. Now that the Phantom series is discontinued, it appears that the Mavic is the obvious choice for a cheap drone. However, do I understand correctly that the camera has a rolling shutter, which is not advisable?
  2. Do you have any experience with the P4 Multispectral? That appears to be a nice option to include NIR, but this model might also be discontinued? Do I understand correctly that there is not much else with an integrated 4 bands camera?
  3. The Zenmuse X4S has a leaf shutter. The brochure claims this eliminates the rolling shutter distortion. Is this correct?
  4. For terrain following, does Maps Made Easy have an option to use an own DTM? UgCS software appears to do that by example, but not sure how good this software is and for what cost? Or do you think the SRTM is good enough?
  5. We use android and therefore I was wondering what the options are, besides Pic4D and Precision Flight. Would Drone Deploy be a good option? Maybe expensive?
  6. Have you come across the Wingtra? That appears to be an interesting development is you want to capture bigger areas. They also have a flight planning software with terrain following.
  7. Do you have recommendations for a minimal number of flight lines to have sufficient overlapping images to create 3D point clouds? This might be something to keep in mind while flying small areas such as inventory plots or narrow strips (transects).

Thanks

Hans Blom
]]> 2021-01-03 23:38:39 UTC https://padlet.com/University_College/5r9iy8w25bmx4okn/wish/1050382238 Key Point Limit in Align Photos (AgiSoft Metashape) https://padlet.com/University_College/5r9iy8w25bmx4okn/wish/1061717529 Hi Darren,
Referring to the presentation on "Agisoft Metashape demonstration Part 1 > 04 - Alignment and pair pre-selection", for a certain image when the number of matched features reach the Key Point Limit (e.g. 40,000), the process stops. Although it is mentioned that the default 40,000 does work very well, I am wondering if this limit has any relationship with the size (coverage) of an individual photo. For example, if images captured with manned aircraft have a relatively larger ground coverage than drone photos, will it be required to use a higher Key Point Limit to increase the number of matched features?

Thanks,
Irfan]]> 2021-01-07 02:27:20 UTC https://padlet.com/University_College/5r9iy8w25bmx4okn/wish/1061717529