Although at first glance they may
appear contradictory, the laws actually describe two uniquely different
concepts.
Mobile LiDAR Law #1: Too
much is better than not enough.
The underlying principle of
this Law is to develop your collection methodology around the concept that Mobile
LiDAR data can be repurposed for other uses/needs; and you NEVER want to make a
repeat visit to a jobsite to collect a little more you could’ve captured the
first time. Take for example an interstate
project where Mobile LiDAR is used in support of engineering design services for
a road surface that is to be substantially undercut for removal and replacement
of unstable soils.
Common among large,
multi-staged construction projects, numerous DOT departments and contractors
may be involved. Each group, with its
own budget, is likely at varying stages of design or construction, and not
necessarily proactively communicating or coordinating activities between groups
that could capitalize on cost-savings. The
scope of work issued by Group A may likely only require survey information for
the lanes slated for reconstruction - without consideration for the engineering
design work needed by Group B for the two crossovers
for maintenance of traffic during construction.
By anticipating Group B’s
needs, and simply modifying the scanning trajectory or extent of capture, you
effectively create a single dataset that not only meets Group A’s requirements,
but also opens the door to re-purpose the data to support Group B
– saving time and money for the client. Obviously not all scenarios are
this cut and dry, and you need to be cognizant that you’re not getting too
carried away collecting additional data that may not be utilized, but when
thoughtfully applied, everybody wins.
Mobile LiDAR Law #2: Sometimes
more is just more, not better.
When the Laws of Mobile LiDAR
were written, Baker was in the process of evaluating an upgrade to an Optech
Lynx M1 system - dual 500 kHz sensor heads. The upgrade would result in a
2.5x increase in the volume of points that we would be capable of measuring.
Although the collection rates would be staggering, would it improve our
ability to identify features better? Do something we weren't capable of doing? Eliminate another process? After all,
the range and scanner rates would not have been any different than our existing
sensors, and the 400,000 measurements per second we can currently capture
produce amazing resolution and rapid ability to identify features.
As you can review in my latest
article on LiDAR News regarding point densities, we left nothing to chance. Our team evaluated the
densities achieved with our system under various conditions and collection
practices. We determined that as we would have more data, not necessarily
better.
The Baker's Dozen was written over a year ago and I've read them countless times since. Each of them still applies today. After I'm finished writing about each of them, I'll step back and reexamine the list one more time before they're chiseled in granite.
Cheers!
Stephen
The Baker's Dozen was written over a year ago and I've read them countless times since. Each of them still applies today. After I'm finished writing about each of them, I'll step back and reexamine the list one more time before they're chiseled in granite.
Cheers!
Stephen
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