**Elevating USGS Science with LiDAR**

**Mark Myers, Director**

**U.S. Geological Survey**

**Second National LiDAR Conference**

**Reston, VA**

**May 21, 2008**

**Title Slide:** *Title slide inset -- US (contiguous) shaded relief*

. Good morning. I'm delighted to join you and discuss how we can make
the most effective use of Lidar - a technology with huge potential --
for the good of USGS science.

**Slide 2:**

. At USGS, we've recently developed a science strategy that we believe
will help our organization -- and our country -- address complex
environmental problems.

. The strategy is based on a systems approach to evaluate broad causes
and consequences of the use and management of natural resources and
earth processes.\
. There are six interrelated thematic components - directions -- in our
science strategy that you see listed in this slide.

. The interaction and correlation of these directions both reflect and
reveal the complexity of the Earth's natural, physical, and life
systems.

. The seventh component, data integration, is the passport to
transcending a discipline-based approach to science. It brings the other
science directions together in the most basic and, at the same time, the
most productive ways.

. The key to data integration is place. Once you have established where
on earth this characteristic is combined with that characteristic, then
you begin to establish geographic context and you can start to ask how
and why such conditions exist at that particular location, or a range of
locations, and not elsewhere. These observations, when carefully
considered and tested, can then lead to a deeper scientific
understanding that can be applied to parallel situations.

. Elevation is a critical aspect of place because natural processes
happen, not in the two dimensions that we see in conventional maps, but
in the three dimensions of the real world. Elevation is as vital in
understanding place as are the horizontal dimensions of longitude and
latitude.

**Slide 3:**

. Founded in 1879, the USGS has a proud tradition of national
topographic mapping that was largely established by John Wesley Powell,
the second USGS director from 1881-94.

. Under Powell, topographic mapping -- that is, maps in which elevation
is the essential, distinguishing quality - was first used to support
geologic mapping. Topographic maps were essential for hydrologic studies
-- an area that Powell also pioneered -- and quickly became the largest
part of the USGS program. At that time, topographic maps were the
premiere instrument for integrating place-based science information.

. This 1884 quote by Powell provides vivid testimony to the importance
he placed in having complete national coverage of topographic maps.

. "A Government cannot do any scientific work of more value to the
people at large, than by causing the construction of proper topographic
maps of the country"

. Paper topographic maps were the GIS of Powell's time, the best mapping
tool available to gain perspective on several categories of geographic
data.

**Slide 4:**

. This next set of slides shows significant developments in mapping
topography at USGS since its formation. Initially charged by Congress
with the \"classification of the public lands,\" the USGS began
topographic and geologic mapping in 1879. Most of the early USGS mapping
activities took place in the vast, largely uninhabited Western United
States.

. Extreme challenges awaited these mapping pioneers. Travel was arduous
and costly. Many locations could be reached only by mule pack train.
Furthermore, surveying and mapping instruments were crude by today\'s
standards. Most maps were made using a classic mapping technique called
planetable surveying.

. Planetable surveying took great skill and, depending on the mapping
site, equal daring. Carrying a planetable - essentially a portable
drawing board on a tripod with a sighting device - the topographer would
climb to the area\'s best vantage point and carefully plot on the map
those features that could be seen and measured in the field. Planetable
surveying remained the dominant USGS mapping technique until the
1940\'s, when it gave way to the airplane and the age of photogrammetry.

**Slide 5:**

. Mapmaking entered a new era with the use of aerial photographs and the
development of photogrammetry - the science of obtaining reliable
information by measuring and interpreting photographs.

. The use of aerial photographs for mapping was pioneered in the
1930\'s, when the USGS assisted the Tennessee Valley Authority in
mapping its area of responsibility. This project was the first
full-scale test of the use of aerial photographs in creating maps.
Aerial photographs increased dramatically during World War II when its
use proved crucial for gathering military intelligence. Aerial
photographs and photogrammetry led to a revolution in mapmaking that
significantly increased map coverage and enhanced map standardization.

**Slide 6:**

. The first DEMs produced by USGS were 7.5-minute quadrangle based. The
limitations of computing in the mid 1970s had much to do with the USGS
format that is still used today with minor modifications. The production
methods, data quality and user expectations of USGS DEMs have changed
significantly since USGS began producing DEMs in the mid 1970s.

**Slide7:**

. Large-scale topographic mapping was completed across the nation in
1991.

. The best known USGS maps are the 1:24,000-scale topographic maps, also
known as 7.5-minute quadrangles. More than 55,000 7.5-minute maps were
made to cover the 48 conterminous States. This is the only uniform map
series that covers the entire area of the United States in considerable
detail.

**Slide 8:**

. The USGS began development of seamless elevation datasets in the early
1990s, first working on continental and global datasets at a resolution
of 1 kilometer.

. The first complete seamless coverage of the continental U.S. was
finished in 1997 based on 10-meter, 30-meter, 2-arc-second, and
3-arc-second resolution data. The National Elevation Dataset (NED is a
seamless raster product produced from diverse source data sets that are
processed to a specification with a consistent resolution, coordinate
system, elevation units, and horizontal and vertical datums.

**Slide 9:**

. In an 11 day mission in February 2000, the Shuttle Radar Topography
Mission (SRTM) finally achieved a three decades long elusive goal of
obtaining a highly accurate globally consistent topographic map of the
Earth's surface.

. NASA in conjustion with NIMA (now NGA) developed SRTM to address some
of the limitations of repeat pass interferometry.

. The SRTM C-band radar system collected data for 99.97% of the Earth's
land mass between -57 degrees and 60 degrees lattitude. The topography
data have an absolute height measurement accuracy of about 9 meters with
a post spacing of about 30 meters. Data from SRTM at 90 m posting is
freely available for download for all areas mapped worldwide and at 30m
posting for the US and its territories.

**Slide 10:**

. In 2000, USGS finished EDNA- Elevation Derivatives for National
Applications.

. EDNA is a multi-layered database derived from a version of the
National Elevation Dataset (NED), which has been hydrologically
conditioned specifically for large-area hydrologic modeling
applications. A primary use of the EDNA layers have been for drainage
basin delineation and characterization.

**Slide 11:**

. In 2003, USGS began integrating lidar into the multi-resolution NED.

. Previously the NED consisted of the 1-arc second (30m) resolution, and
the 1/3rd-arc second (10m) resolution, produced mainly from USGS Digital
Elevation Models. The high resolution and high accuracy available from
lidar remote sensing data allowed for the integration at the 1/9th
arc-second, or 3 meter level. amount of detail that is available at this
resolution is tremendous. The other advantage is that with these new
data collections we not only have increased resolution and accuracy, but
have updated the elevation temporally as well.

**Slide 12:**

. In 2005, USGS began providing web-based application tools based on
elevation data.

. The advantage of this is that the end user does not have to spend
their time prepping the data for analysis, they can interactively
perform queries on massive datasets that exist on a server, and have a
result processed for them utilizing the large databases and computing
power USGS has. This method can greatly reduce the amount of time a user
needs to process the data, which frees them up to have more time to
perform actual scientific analyses.

**Slide 13:**

. The future of topographic mapping is not just elevation of the bare
earth; it is the vertical distribution of objects and vegetations on the
earth's surface - turning our mapping paradigm from a two-dimensional to
a three dimensional one.

. Technologies such as Lidar allow us to get a more realistic
representation of the earth, and allows for actual measurements on
vertical components previously difficult to be measured directly such as
biomass estimations, carbon stocks, infrastructure, land cover- we have
only scratched the surface on how much information Lidar remote sensing
data really contains.

**Slide 14:**

. The first major USGS discussion of a national lidar capability came at
a USGS Lidar Workshop in November of 2002.

. In 2003-4 discussions and announcements began regarding commercial
vendors and a national survey. Discussions continued at the USGS
elevation summit in 2005.

. In June of 2005 we published a highlight article in PE&RS on USGS
applications of lidar which mentioned the need for a national lidar
survey. In June 2006 we published a highlight article in PE&RS about the
new USGS Center for Lidar Information Coordination and Knowledge
(CLICK), and how we were attempting to integrate disparate lidar
datasets into a national framework.

. In February 2007, USGS hosted the first National Lidar Initiative
meeting to discuss requirements and strategy for a potential lidar
collection.

. And, in May 2008, we continue.

**Slide 15:**

. This audience, I'm sure, needs no convincing that LiDAR is an
extremely versatile imaging system that can provide much more data than
ground elevation. But let's look together at a few remarkable things
that Lidar can do so that we can all be, so to speak, on the same
wavelength.

. The example on this slide shows just how much information is available
in a 'raw' lidar point cloud.

. This is an old-growth ponderosa pine in Colorado; on the left, of
course, its corresponding LiDAR point cloud. The colors represent the
multiple returns a LiDARsystem can record as the light beam penetrates
the vegetation canopy to reach the ground below.

\_\_\_\_\_\_\_\_\_\_

(Yellow=first return, blue=second, red = third return, purple=fourth).

**Slide 16:**

. Since LiDAR data is traditionally used to create bare earth DEMs,
usually points corresponding with buildings are discarded similarly to
vegetation.

. This is a point cloud representation of New Orleans, LA. In the
current scheme, all of this building information is usually discarded to
create a bare earth DEM. There is a tremendous amount of infrastructure
information that could be leveraged from a complete lidar dataset if the
source data and the appropriate skills are available.

**Slide 17:**

[Image: Seattle fault scarp in Lidar]{.underline}

. Our ability to characterize the hazard in regions like the Pacific
Northwest where active faults are poorly exposed has been revolutionized
by high-resolution LIDAR.

. As in this example from Bainbridge Island, LIDAR images can reveal
fault scarps that are hidden beneath vegetation. This technology has
many applications.

**Slide 18:**

*Image: Flooding in Eastern Kentucky , March 2002; flood waters on the
Cumberland River near Pineville, KY.*

. The National Research Council initiated this study to advise Congress
and the nation on the issue of accurate floodplain mapping. Floodplain
maps serve as the basis for determining whether homes or buildings
require flood insurance under the National Flood Insurance Program run
by the Federal Emergency Management Agency (FEMA). Approximately \$650
billion in insured assets are now covered under the program.

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

Floodplain maps serve as the basis for determining whether homes or
buildings require flood insurance under the National Flood Insurance
Program run by the Federal Emergency Management Agency (FEMA).
Approximately \$650 billion in insured assets are now covered under the
program. The National Research Council initiated this study to advise
Congress and the nation on the issue. The report concludes that there is
sufficient two-dimensional \"base map imagery\" available from digital
orthophotos (aerial and satellite photographs similar to those viewed on
Google Earth) to meet FEMA's flood map modernization goals. However, the
three-dimensional \"base elevation data\" that are needed to determine
whether a building should have flood insurance are not adequate. FEMA
needs land surface elevation data that are about ten times more accurate
than data currently available for most of the nation. The report
recommends that new, high-accuracy digital elevation data be collected
nationwide using laser measurements from aircraft (LIDAR technology).
The new data should be input into the National Elevation Dataset that
the U.S. Geological Survey maintains for use in support of flood map
modernization and other applications.

**Slide 19:**

The NRC study made the following recommendations:

1\) A revised national program of elevation data acquisition (called
"Elevation for the Nation" in the report) should employ Lidar as the
primary technology for digital elevation data acquisition. Lidar is
capable of producing a bare-earth elevation model with 2-foot equivalent
contour accuracy in most terrain and land cover types; a 4-foot
equivalent contour accuracy is more cost-effective in mountainous
terrain, and a 1-foot equivalent contour accuracy can be achieved in
very flat coastal or inland floodplains.

2\) A seamless nationwide elevation model has application beyond the
FEMA Modernization program.

3\) The new data should be disseminated to the public as part of an
updated National Elevation Dataset (http://ned.usgs.gov/).

4\) The updated elevation database should contain the original Lidar
mass points and edited bare-earth surface, as well as any breaklines
required to define essential linear features.

**Slide 20:**

These observations collectively argue for USGS leadership of a
coordinated national Lidar program:

\+ There is a strong need for consistent, accurate high resolution
elevation data by state, federal and local users.

\+ The USGS is looked to as the lead agency for terrestrial elevation
(OMB Circular A-16).

\+ Lidar is a proven technology to achieve this.

\+ Lidar remote sensing provides more information than just bare earth
elevation.

\+ Many state and federal agencies are already using Lidar to meet their
missions.

**Slide 21:**

. We need to have a national LIDAR survey -- LiDAR for the Nation -- a
program that builds on the successes of regional partnerships like the
Puget Sound Lidar Consortium and extends those benefits nationwide. A
complete, consistent, current, high res LIDAR dataset would have great
value for multiple stakeholders, many applications.

. Planning and execution of the program would involve partners from
local, state, and Federal government agencies, the private sector, and
academia. A base level specification would be supported by Federal
funding, with upgrades funded by organizations with higher level
requirements.

. Data acquired through the program would be in the public domain (no
licensing restrictions).

. The USGS CLICK website (Center for LIDAR Information Coordination and
Knowledge) helps coordinate, leverage LiDAR data requests and inquiries.

http://lidar.cr.usgs.gov/

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

. Slide inset shows forest vegetation in prefire and post wildfire
conditions.

CLICK website http://lidar.cr.usgs.gov/index.php

**Slide 22:**

Potential actions for an Interagency National Lidar Working Group:

\+ Provide support of NASA 2008 prototype flight(s) for analyses and
comparisons to existing data.

\+ Conduct cost/benefit analysis of high altitude and low-altitude data
collection and product derivation.

\+ Assess approaches for including National Lidar program start-up in
FY10 funding request.

**Slide 23:**

. As I said at the outset in outlining the directions of the USGS
Science Strategy, our science has a critical role to play in
understanding the complex processes that occur within natural systems.
And then, in a broader context, understanding how human activities
interact with natural systems. Lidar can assist gathering fundamental
data relevant to every science direction.

. We need to understand how potential decisions to build a suburban
development in the Chesapeake Bay watershed and the resulting runoff
affect Chesapeake fisheries and various freshwater and recreational
resources. We need the same kind of understanding of natural systems in
the Colorado River basin, the Everglades and Puget Sound, in the
oilfields of Wyoming and Alaska, in every county that requires good
science about water supplies, in every municipality that faces
environmental trade-offs with urban growth. Lidar can provide basic data
to help us do that.

**Slide 24:**

. We must be able to link our science to decision making so that
tradeoffs across conservation, restoration, resource management, and
development are informed and fully considered. We want the best science
to be routinely and effectively used in making wise decisions for the
environment, for people, for our Nation.

. A vibrant national program to collect, analyze, archive, and
distribute Lidar data -- a program based on partnerships across agencies
and various levels of government -- will be an important tool in
producing the highest quality natural science for the Nation.

\_\_\_\_\_\_\_\_\_\_\_\_\_\_

In a cooperative research program, the USGS, NASA and the U.S. Army
Corps of Engineers (USACE) have used airborne laser mapping systems
(Lidar) to survey coastal areas before and after hurricanes.

Images from USGS Center for Coastal and Watershed Studies website.

http://coastal.er.usgs.gov/hurricanes/katrina/lidar/dauphin-island.html

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