PHOTOGRAMMETRIC ENGINEERING & REMOTE SENSING
April 2018
173
ASPRS S
ummary of
R
esearch
and
D
evelopment
E
fforts
N
ecessary
for
A
ssuring
G
eometric
Q
uality
of
L
idar
D
ata
S
ummary
To summarize, the US Geological Survey (USGS)/ASPRS Li-
dar Data Quality Working Group, or sometime referred to as
the “ASPRS Lidar Cal/Val Working Group, referred to in the
rest of this document as WG, has investigated various factors
associated with the geometric quality of lidar data. The WG
has noted that while the quality of lidar data have improved
tremendously in the past few years, the QA/QC of these data
are not standardized including the semantics, processes for
measurement and reporting and meta data. Therefore, to en-
sure the geometric quality of that lidar data required for scien-
tific (statistical error propagation and estimation) and non-sci-
entific purposes (including legal), the WG has recommended
several topics for research and development.
To quantify the noise level in the data, the WG recommends
research and development efforts towards answering the fol-
lowing questions:
•
How should the inter swath “noise” be mathematically
defined?
•
How should measurements be made to quantify inter-
swath noise?
•
How should these measurements be summarized (in
terms of mean, median, standard deviation, and spatial
distribution, etc.)?
On Inter Swath analysis, the WG further recommends that
government agencies, academia and the industry work to-
gether towards determining acceptable solutions to the fol-
lowing questions
•
Are current thresholds for relative accuracy valid?
•
Are the thresholds measurable?
•
Should the thresholds be different for different terrain?
•
What should be the thresholds for the discrepancy angles?
The WG also recommends a comprehensive error library con-
sisting of systematic errors and their sources be documented
and maintained, for current as well as future lidar technolo-
gies.
Towards measuring the absolute accuracy of lidar data, the
WG recommends that the following studies be undertaken:
•
Cost of deploying 3D accuracy assessment targets as a
percentage of total project cost, project size, terrain con-
ditions, etc.
•
Research on estimation of absolute three-dimensional
accuracy of lidar data using latest technologies, includ-
ing mobile lidar, static lidar, and UAV data.
Towards assessment of national lidar geometric quality and
consistency, the WG recommends that research efforts are di-
rected to answer the following topics:
•
How should inter project lidar data consistency be
mathematically defined?
•
How should the data consistency metrics be measured?
•
How should must data acquisition be specified to ensure
consistency of features across spatial extents of differ-
ent projects?
•
Are there new technologies that can assist in enhancing
inter project lidar data quality?
Photogrammetric Engineering & Remote Sensing
Vol. 84, No. 4, April 2018, pp. 173–177.
0099-1112/17/173–177
© 2018 American Society for Photogrammetry
and Remote Sensing
doi: 10.14358/PERS.84.4.173
