Skip to content

Forensic Photogrammetry Training, Products and Services

Home
Blog
Photogrammetry Training
Webinars
About Us
Contact Us
Shop
My Account
£0.00 0 items

Quizzes

Quiz – Laser Scans in Zephyr

April 14, 2023 SimonBrown

This quiz covers the topics in the

Time limit: 0

Quiz Summary

0 of 14 Questions completed

Questions:

Information

You have already completed the quiz before. Hence you can not start it again.

Quiz is loading…

You must sign in or sign up to start the quiz.

You must first complete the following:

Results

Quiz complete. Results are being recorded.

Results

0 of 14 Questions answered correctly

Your time:

Time has elapsed

You have reached 0 of 0 point(s), (0)

Earned Point(s): 0 of 0, (0)
0 Essay(s) Pending (Possible Point(s): 0)

Categories

Not categorized 0%

1
2
3
4
5
6
7
8
9
10
11
12
13
14

Current
Review
Answered
Correct
Incorrect

Question 1 of 14

1. Question
Why do we treat laser scans as fixed objects?
- Because they are stationary
- Because they are dynamic
- Because they are the more precise.
- Because they are smaller.
Question 2 of 14

2. Question
Does alignment of dense clouds and laser scans have to be fully manual?
- Yes
- It depends on the presence of control points.
- There are manual, guided and fully automatic options.
- It depends on the software
Question 3 of 14

3. Question
What do you need to do before automatic alignment?
- Manually align the point clouds
- Remove all noise from the point clouds
- Filter the point clouds
- Roughly align the point clouds
Question 4 of 14

4. Question
What is required for the most accurate dense cloud to laser scan alignment?
- High quality scans and sparse clouds
- Automatic alignment
- Manual alignment
- The presence of common control points in both point clouds.
Question 5 of 14

5. Question
When attempting to match a dense cloud to a laser scan what minimum quality in “points per image” and “mean reprojection error” should we expect?
- 500 points per image and 0.1 mean reprojection error
- 500 points per image and 0.5 mean reprojection error
- 100 points per image and 1.0 mean reprojection error
- This statistic is variable depending on camera quality, site conditions and client requirements.
Question 6 of 14

6. Question
When would we reconsider the data set is unviable and reshoot?
- If the colour balance is off
- If the camera settings are incorrect
- If we judge that the photo data set does not give a good enough quality of alignment.
- If the laser scans are from a different day to the photo data.
Question 7 of 14

7. Question
Why do we use a bounding box before dense cloud generation?
- To limit the area of reconstruction to match the laser scan.
- To increase the area of reconstruction.
- To create a smoother dense cloud.
- To match the geolocation with the laser scan.
Question 8 of 14

8. Question
Why do you not need to build a mesh before aligning with a laser scan?
- Because the dense cloud automatically adds GCP.
- Because the mesh is not necessary for alignment
- Because the dense cloud is already a mesh
- Because no scaling has been applied and the laser scan will accomplish this later.
Question 9 of 14

9. Question
How precise do GCPs added to dense clouds need to be?
- Within 1 meter
- Within 10 centimetres
- The precision of placement is less important than the general location, order and naming.
- Within 1 centimetre
Question 10 of 14

10. Question
When placing GCP what is a sensible method to ease the following workflow?
- Place the GCPs randomly throughout the scene
- Place the GCP clockwise in each data set, roughly in the same spots with matching names.
- Place the GCPs in a grid pattern
- Place the GCPs near the edges of the scene
Question 11 of 14

11. Question
What is the minimum number of GCP required for alignment?
- 1
- 7
- 3
- 5
Question 12 of 14

12. Question
Can you edit the GCP once the alignment has been started?
- Only absolute geolocation
- Only names
- Only relative accuracy
- No
Question 13 of 14

13. Question
Why is it important to review the histogram and bell curve of point distribution after cloud alignment?
- They help us understand how long processing will take in future.
- They offer a measure of the quality of dense to laser cloud registration
- They help us know the quality of the laser scan
- They have no purpose but are often demanded by clients
Question 14 of 14

14. Question
When we structure and align the laser scan with the dense cloud, what is the advantage?
- It allows for easier editing and manipulation of the data
- It provides a denser and more accurate representation of the scene
- It reduces the size of the data set
- It reduces time on site.

Blog
Photogrammetry Training
Webinars
About Us
Contact Us
Shop
My Account

Search Our Site:

Our Customers:

Our Blog:

New – Customer Helpdesk Tickets
Reverse Engineering: Creating Discontinued Spare Parts with Photogrammetry, 3D Scanning, and 3D Printing.
Course Update – Manual Camera Calibration

Copyright © 2023 AccuPixel Ltd

Login

Accessing this course requires a login. Please enter your credentials below!

Username or Email Address

Password

Remember Me

Lost Your Password?