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Author Topic: mixing arial photos with highly accurate GPS coordinates  (Read 2128 times)

sswallace

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mixing arial photos with highly accurate GPS coordinates
« on: August 22, 2018, 03:53:36 PM »
In search of a more accurate orthomosaic:

I'm using a phantom 4 pro to collect images to process using photoscan. I have the ability to tag some of the photos with very accurate GPS locations (within a few cm). If I have a project with 100 images using the standard 10 meter default accuracy, can I add 10 photos where i specify  much greater accuracy, and have photoscan use those as aerial GCPs?

For the curious: I've equipped by phantom with a Reach M+ GPS. I log raw GPS data during a mission, and post process the data using EZsurv. The problem is that the image timestamps aren't accurate enough to use the more accurate GPS data. My idea is to fly a normal mapping mission, then manually hover the drone at various locations and manually take the photo. Based on my testing, manually taking a photo while hovering ensures the timestamp is within the correct second, and drone will generally stay within 10 cm during that second if it isn't windy.


Alexey Pasumansky

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Re: mixing arial photos with highly accurate GPS coordinates
« Reply #1 on: August 23, 2018, 05:31:53 PM »
Hello sswallace,

For the cameras with the precise GPS information you can set individual accuracy in the Reference pane: select those cameras in the pane, right-click on selection and choose Set Accuracy option. Individual accuracy will have priority over default value defined in the Reference pane settings dialog.
Best regards,
Alexey Pasumansky,
Agisoft LLC

Alex737

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Re: mixing arial photos with highly accurate GPS coordinates
« Reply #2 on: August 24, 2018, 07:35:31 AM »
Fly north-south, west east. Pictures north-south, full-east coordinates 0.1 m, north coordinates 10 m. Photos west-east similarly, north 0.1 m, east 10 m. But still you will not get normal accuracy. Contact www.topodrone.com, emlid is synchronized with the camera.

WSurvey

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Re: mixing arial photos with highly accurate GPS coordinates
« Reply #3 on: August 26, 2018, 11:57:56 AM »
In search of a more accurate orthomosaic:

I'm using a phantom 4 pro to collect images to process using photoscan. I have the ability to tag some of the photos with very accurate GPS locations (within a few cm). If I have a project with 100 images using the standard 10 meter default accuracy, can I add 10 photos where i specify  much greater accuracy, and have photoscan use those as aerial GCPs?

For the curious: I've equipped by phantom with a Reach M+ GPS. I log raw GPS data during a mission, and post process the data using EZsurv. The problem is that the image timestamps aren't accurate enough to use the more accurate GPS data. My idea is to fly a normal mapping mission, then manually hover the drone at various locations and manually take the photo. Based on my testing, manually taking a photo while hovering ensures the timestamp is within the correct second, and drone will generally stay within 10 cm during that second if it isn't windy.

Hello sswallace,

If you ever log in again I’ve sent you a PM. I’m doing similar things to yourself. Hopefully we can swap some ideas.