GeoSlam data and level to ground

Discuss all GeoSlam related products here
Post Reply
cbresloff
I have made <0 posts
I have made <0 posts
Posts: 2
Joined: Wed Aug 28, 2019 4:38 pm
Full Name: Cynthia Bresloff
Company Details: Jacobs
Company Position Title: Project Solutions lead
Country: United States
Linkedin Profile: Yes
Been thanked: 1 time

GeoSlam data and level to ground

Post by cbresloff » Mon Sep 23, 2019 6:26 pm

Hi folks,

I have a bit of an ignorant question to ask about the Zeb Revo units. My company purchased a few of the Zeb Revo units before I came on board, so I've probably missed some info about what they can and cannot do; yet I am now an end user of one. I understand the units have an IMU but I am unclear on whether or not this implies whether the units 'know' where level to ground is, in the scan data (I suspect it depends on the particular IMU?) . I think of the generated point clouds from the Zeb units as giving location information in a relative sense and not absolute; yet the scans appear to bring the data in relatively 'level'. Is this something I can count on, that the data is oriented with some accuracy relative to level ground, or not?
Thanks.

tbwester
V.I.P Member
V.I.P Member
Posts: 891
Joined: Fri Apr 20, 2012 1:49 pm
Full Name: Thad Wester
Company Details: WeWork
Company Position Title: Head of Reality Capture
Country: USA
Linkedin Profile: Yes
Location: SC/NYC
Has thanked: 1 time

Re: GeoSlam data and level to ground

Post by tbwester » Mon Sep 23, 2019 7:52 pm

when you start the revo (on a basically flat unmoving surface), it sets the level for your scan. We count on the scans being basically level, not sure exactly how good it is, but we find it to be good compared to our higher end tripod scanners.

User avatar
stutosney
I have made 50-60 posts
I have made 50-60 posts
Posts: 58
Joined: Tue May 15, 2018 5:55 am
Full Name: Stuart Tosney
Company Details: Vitruvius Ltd
Company Position Title: Lead Surveyor
Country: New Zealand
Linkedin Profile: Yes

Re: GeoSlam data and level to ground

Post by stutosney » Tue Sep 24, 2019 9:58 pm

It has been a while since I used it, but from memory it uses the initial start up as your level plane, and then the rest of the data is based around that. I think it was similar to the BLK, it uses the first scan as the plane and then relates that to the rest of the scans.

User avatar
gsisman
V.I.P Member
V.I.P Member
Posts: 278
Joined: Fri Oct 07, 2016 1:51 pm
Full Name: Steve Long
Company Details: Montgomery County DOT _ MD
Company Position Title: Land Survey Supervisor
Country: United States
Skype Name: gsisman1
Linkedin Profile: Yes
Has thanked: 27 times
Been thanked: 7 times

Re: GeoSlam data and level to ground

Post by gsisman » Wed Sep 25, 2019 2:15 pm

stutosney wrote:
Tue Sep 24, 2019 9:58 pm
It has been a while since I used it, but from memory it uses the initial start up as your level plane, and then the rest of the data is based around that. I think it was similar to the BLK, it uses the first scan as the plane and then relates that to the rest of the scans.
Does anyone know that when using these geoslam devices that you can walk close to and densely scan,say a wall target and then add that control into the processing scan cloud to more precisely tie to control coordinate system bot vertically and horizontally?

VXGrid
I have made 80-90 posts
I have made 80-90 posts
Posts: 83
Joined: Fri Feb 24, 2017 10:47 am
Full Name: Martin Graner
Company Details: PointCab GmbH
Company Position Title: Research and Development
Country: Germany
Linkedin Profile: No
Has thanked: 1 time
Been thanked: 2 times

Re: GeoSlam data and level to ground

Post by VXGrid » Wed Sep 25, 2019 2:53 pm

gsisman wrote:
Wed Sep 25, 2019 2:15 pm
Does anyone know that when using these geoslam devices that you can walk close to and densely scan,say a wall target and then add that control into the processing scan cloud to more precisely tie to control coordinate system bot vertically and horizontally?
There is now a way to include control points into the SLAM algorithm with the new version of Hub.

If you just want to georeference the local point cloud you can do that with that approach as well, or use GeoSLAM Draw (Transformation calculator - 7 parameter transformation) to gereference the cloud using spheres/checkerboard targets.

Mokeefe
I have made 20-30 posts
I have made 20-30 posts
Posts: 24
Joined: Tue Apr 23, 2019 8:47 pm
Full Name: Mark OKeefe
Company Details: Clearedge3D
Company Position Title: Clearedge3D
Country: USA
Skype Name: markokeefe4
Linkedin Profile: Yes
Has thanked: 27 times
Been thanked: 3 times

Re: GeoSlam data and level to ground

Post by Mokeefe » Wed Sep 25, 2019 7:08 pm

cbresloff wrote:
Mon Sep 23, 2019 6:26 pm
Hi folks,

I have a bit of an ignorant question to ask about the Zeb Revo units. My company purchased a few of the Zeb Revo units before I came on board, so I've probably missed some info about what they can and cannot do; yet I am now an end user of one. I understand the units have an IMU but I am unclear on whether or not this implies whether the units 'know' where level to ground is, in the scan data (I suspect it depends on the particular IMU?) . I think of the generated point clouds from the Zeb units as giving location information in a relative sense and not absolute; yet the scans appear to bring the data in relatively 'level'. Is this something I can count on, that the data is oriented with some accuracy relative to level ground, or not?
Thanks.
There should be a process to tie in survey points and levels. If that isn't accurate enough, you might want to check on a higher end mobile scanner like the Heron. It lets you tie in points and levels, and even use terrestrial scans as controls.

User avatar
stutosney
I have made 50-60 posts
I have made 50-60 posts
Posts: 58
Joined: Tue May 15, 2018 5:55 am
Full Name: Stuart Tosney
Company Details: Vitruvius Ltd
Company Position Title: Lead Surveyor
Country: New Zealand
Linkedin Profile: Yes

Re: GeoSlam data and level to ground

Post by stutosney » Thu Sep 26, 2019 2:18 am

gsisman wrote:
Wed Sep 25, 2019 2:15 pm
stutosney wrote:
Tue Sep 24, 2019 9:58 pm
It has been a while since I used it, but from memory it uses the initial start up as your level plane, and then the rest of the data is based around that. I think it was similar to the BLK, it uses the first scan as the plane and then relates that to the rest of the scans.
Does anyone know that when using these geoslam devices that you can walk close to and densely scan,say a wall target and then add that control into the processing scan cloud to more precisely tie to control coordinate system bot vertically and horizontally?
As far as I know, you can acquire targets with the Zeb Revo devices. I didn't do it myself but I remember speaking with GeoSlam and they said it can be part of the normal workflow, this was about 3 years ago.

Post Reply

Return to “GeoSLAM”