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Author Topic: GROUND ALTITUDE option meaning in the reference setting panel  (Read 6030 times)

FLORIANO

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GROUND ALTITUDE option meaning in the reference setting panel
« on: November 06, 2015, 12:58:29 PM »
Hi,
I'm using PhotoScan version 1.1.4, I found a new option in the "Reference Settings" panel: Ground Altitude.
I would like to know what it refers to exactly. I guess it refers to the distance between ground and camera. But the value that I have to insert in the box refers to all the photos, even if the distnce could be not the same for evry pictures.
In the end what's the advantage in using this options?
Could anyone help me?
Thanks.

Alexey Pasumansky

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Re: GROUND ALTITUDE option meaning in the reference setting panel
« Reply #1 on: November 06, 2015, 01:10:32 PM »
Hello FLORIANO,

Ground altitude parameter is used to make Reference preselection mode of alignment procedure work
effectively for oblique imagery. Ground altitude information must be accompanied with yaw, pitch, roll data for cameras. Yaw, pitch, roll data should be input in the Reference pane.
The average height above ground should be input to the Ground Altitude field.
Best regards,
Alexey Pasumansky,
Agisoft LLC

mcstieg

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Re: GROUND ALTITUDE option meaning in the reference setting panel
« Reply #2 on: December 30, 2017, 06:31:35 PM »
Hello Alexey,

this is from the user manual:
" For oblique imagery, it is necessary to set Ground altitude
value (average ground height in the same coordinate system which is set for camera coordinates data) "

Let's say my drone is flying at 20 m above a flat surface and the (average) GPSAltitude of my drone is 300 m MSL.
Should I set the ground altitude to 280 m if the coordinate system is WGS 84?

Thank you!

Alexey Pasumansky

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Re: GROUND ALTITUDE option meaning in the reference setting panel
« Reply #3 on: December 30, 2017, 07:19:18 PM »
Hello mcstieg,

If the GPS height of the flight is 300 meters and average above ground level height is 20 meters, then you should set Ground Altitude parameter to 280 meters.
Best regards,
Alexey Pasumansky,
Agisoft LLC

Karen Morgan

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Re: GROUND ALTITUDE option meaning in the reference setting panel
« Reply #4 on: May 24, 2018, 10:32:31 PM »

 Hello,

  What if I don't have any pitch, roll or yaw data for the my oblique images? Should I not use Ground Altitude? 

    Karen