Data QC/QA & Alignment (GCPs)

QA/QC Your Dataset & Align to GCPs


Now that you've created and edited your point cloud in the ROCK Cloud, you will want to ensure the data is aligned to GCPs and perform your final QA/QC checks so you can order your deliverables.


Visual Verification: Aesthetic Assessment


First, you will want to visually inspect the dataset for completeness and overall quality. We like to run through these particular views when we visually assess a point cloud:

  • Elevation View: Ensure that all data points are present and that there are no major gaps or missing information. Assess for data fuzz.
  • GPS Time View: Assess alignment of the LiDAR Data on some key objects to get a general feeling for the potential presence of any misaligned data problem areas.
  • RGB View: look at the general quality of the colorized data
  • Intensity View: Compare Intensity View to RGB to ensure they match on key areas like an aerial target


Aligning Your Point Cloud to your GCPs


Next, we want to align the point cloud to our specific reference points (GCPs). This is an essential step to guarantee our point cloud accuracy. Here's how we like to do it:

  1. Start by viewing your point cloud in Intensity View
  2. Locate your aerial target in the Intensity view, along with the matching GCP
  3. Click the Quick Tools tab on your tool bar and locate the Auto Align button
  4. Select a custom point and then place that point in the center of your aerial target
  5. Select the corresponding GCP and then click the align button. Fine tune as desired using the Navigate tool to perform micro movements of the GCP to the center of your aerial target. This should move your entire point cloud into alignment.
  6. Now check the alignment of your other GCPs to the aerial target to ensure they moved as expected.


Wrapping Up: Order Your Deliverables with Confidence


Once the dataset has been visually validated and accurately aligned, you can move forward with confidence to order deliverables such as ROCK Surveyor and Planimetrics from the ROCK Marketplace. We will cover that in the next modules.


Complete and Continue