FAQs for Photogrammetric Product
Were the UAV images used to generate the
photogrammetric products georeferenced?
Yes, they have already been georeferenced. The
provided block file contains the orientation
parameters.
What parameters were used while running the Cloth
Simulation Filter for generating the Ground and
Off-Ground points?
The "scene" parameter was set to flat since the
terrain in The Netherlands is generally flat. The
other parameters were kept default.
How were interpolation distances for the rasterization
of the photogrammetric products (DSM & DTM) chosen?
The interpolation was performed using the least
distance possible such that there would be no holes in
the raster (DSM and DTM) after the rasterization
process.
How were the checkpoints for estimating the RMSE
values for the DSM and the DTM chosen?
Spatial spread of the checkpoints is the main criteria
while choosing. For the DSM, the chosen checkpoints
lie on roads, cycle lanes, and building tops, while
for the DTMs we chose only roads and cycle lanes. We
avoided croplands and forested areas due to their
seasonal growth variability.
What is the reasoning behind representing Uncertainty
using circles?
In our work, uncertainty is calculated as the
difference in elevations between our photogrammetric
products and the AHN reference data. Since this is an
absolute value, it can be represented adequately using
Size as a graphic variable. Hence, the uncertainty is
represented using the diameter of the circle.
What are the metrics of the tie points generation and
block adjustment?
You can find the tie point generation report
click here (Text) .
You can find the block adjustment report
click here (Text) .
FAQs for Website
Where is the data stored?
The point cloud is stored in ITC servers. DSM, DTM,
and related files are stored in Firebase.
Why did we use Firebase?
Firebase is lightweight and flexible. It is capable of
storing and syncing data in real-time across all
devices.
What open standards and web services are used?
OSM maps from Leaflet.
What tools were used for rendering the photogrammetric
products on the Client Side?
Leaflet for 2D data, Potree for 3D point cloud
rendering.
What tools were used in website design?
Figma for UI design, HTML, CSS, JS, and Bootstrap for
development.
How is the feedback handled?
You can find the response sheet for feedback
here (PDF) .