Western Coastal and Marine Geology

Applicability of Terrestrial LIDAR Scanning for 

Scientific Studies in Grand Canyon National 

Park, Arizona 

By Brian D. Collins and Robert Kayen 

U.S. Geological Survey, Menlo Park, California 

Open File Report 2006–1198 

U.S. Department of the Interior 

U.S. Geological Survey
ii

U.S. Department of the Interior 

Dirk Kempthorne, Secretary 

U.S. Geological Survey 

P. Patrick Leahy, Acting Director 

U.S. Geological Survey, Reston, Virginia 2006 

Revised and reprinted: 2006 

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Suggested citation: 

Collins, Brian D., Kayen, Robert, 2006, Applicability of Terrestrial LIDAR Scanning for 

Scientific Studies in Grand Canyon National Park, Arizona: U.S. Geological Survey, 

Open File Report 2006-1198, 27pg; [available on the World Wide Web at URL 

http://pubs.usgs.gov/of/2006/1198/ ]. 

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endorsement by the U.S. Government. 

Although this report is in the public domain, permission must be secured from the individual 

copyright owners to reproduce any copyrighted material contained within this report. 
iii

Contents 

Introduction ...................................................................................................................................1

Methodology..................................................................................................................................3

Mile 30 Sand Bar...........................................................................................................................5

Background................................................................................................................................5

Data ...........................................................................................................................................5

Processing ...............................................................................................................................10

Results .....................................................................................................................................11

Conclusions and Recommendations........................................................................................12

Vaseys Paradise (Mile 32) ..........................................................................................................16

Background..............................................................................................................................16

Data .........................................................................................................................................16

Processing ...............................................................................................................................16

Results .....................................................................................................................................17

Conclusions and Recommendations........................................................................................17

Palisades Arroyo Archaeological Site (Mile 66)...........................................................................20

Background..............................................................................................................................20

Data .........................................................................................................................................21

Processing ...............................................................................................................................22

Results .....................................................................................................................................22

Conclusions and Recommendations........................................................................................22

General Conclusions...................................................................................................................25

Acknowledgments .......................................................................................................................25

References Cited ........................................................................................................................26

Figures 

Figure 1. Location map of terrestrial LIDAR studies within Grand Canyon National Park during 

the November 2004 High Flow Experiment...................................................................................2

Figure 2. The USGS Coastal and Marine Geology program’s terrestrial LIDAR unit....................4

Figure 3. The Mile 30 Sand Bar Site. ...........................................................................................7
iv

Figure 4. Mile 30 Sand Bar Site showing locations of laser set-up points (triangles) and survey 

control points (circles). ..................................................................................................................7

Figure 5. Laser scan data of Mile 30 Sand Bar showing footsteps and tripod control point setup. 

Black area indicates area where no data was collected beneath the tripod and outside of the 

336° data collection area of the laser............................................................................................8

Figure 6. Point cloud data of Mile 30 Sand Bar showing trees and survey features.....................8

Figure 7. Mile 30 Sand Bar showing both laser data and “sky points” of background (non-laser) 

data. ..............................................................................................................................................9

Figure 8. Views of final DTM surface of Mile 30 Sand Bar from the sand bar scan set (labels 

indicate location of control points). One-meter contour elevations are shown relative to 

NAVD88. .....................................................................................................................................13

Figure 9. Location of cross sections at the Mile 30 Sand Bar site. .............................................14

Figure 10. Selected cross sections of the Mile 30 Sand Bar. Both sand bar (blue) and crossriver (green) data sets are shown, but appear as one line due to the nearly identical surface 

matching that was obtained. Arrows delineate upper slope discrepancies in and near 

vegetation....................................................................................................................................15

Figure 11. Vaseys Paradise with laser scanning equipment in foreground. ...............................18

Figure 12. Vaseys Paradise (Mile 32) site map showing LIDAR scan locations.........................18

Figure 13. Composite scan data for Vaseys Paradise................................................................19

Figure 14. Completed fusion surface of Vaseys Paradise cliff topography.................................19

Figure 15. Vaseys Paradise data showing area of Kanab Ambersnail habitat removed prior to 

high flow experiment. ..................................................................................................................20

Figure 16. Location of LIDAR scanning at the Palisades Site. ...................................................23

Figure 17. Palisades Site – Oblique view of unprocessed scan data showing heavy laser returns 

from vegetation. ..........................................................................................................................24

Figure 18. Palisades Site – Vertical view of unprocessed scan data showing heavy laser returns 

from vegetation and limited range distance.................................................................................24

Tables 

Table 1. Survey Control for Mile 30 Sand Bar...............................................................................6
v

Datum Information 

Vertical coordinate information is referenced to the North American Vertical Datum of 1988 (NAVD 88). 

Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83) and projected to 

Arizona Central Zone 0202 State Plane coordinates. 

Elevation, as used in this report, refers to distance above the vertical datum. 

Metadata for the products described in this report are available at: 

http://walrus.wr.usgs.gov/infobank/r/r104gc/html/r-1-04-gc.geo.html
Applicability of Terrestrial LIDAR Scanning for 

Scientific Studies in Grand Canyon National 

Park, Arizona 

By Brian D. Collins and Robert Kayen 

Introduction 

In November 2004, an experimental high flow release of water from Glen Canyon Dam into the 

Colorado River through Grand Canyon National Park in Arizona was conducted. The goal of the 

experiment was to evaluate the use of high flow events as a management tool for the preservation and 

restoration of natural resources in the Colorado River below Glen Canyon Dam. The U.S. Geological 

Survey (USGS), Grand Canyon Monitoring and Research Center (GCMRC) located in Flagstaff, 

Arizona performed oversight of all aspects of scientific data collection including suspended sediment 

transport studies, biological population variations, effects on archaeological resources, and 

morphological studies of river sand bars. 

As part of the experimental high flow studies, the USGS Coastal and Marine Geology (CMG) 

team was invited to participate to test the effectiveness of utilizing terrestrial LIDAR technology for 

gathering morphological data on sand bars, biological habitats, and archaeological sites. The CMG is 

equipped with a terrestrial LIDAR unit and has used the technique in a variety of terrains to gather highresolution morphological data (e.g. Collins and Sitar, 2002, 2004, 2005; Kayen and others, 2004, 2006, 

1
Collins and Kayen, 2005). A three-member team from CMG participated in the experiment, joining a 

GCMRC team on a river trip from November 18 to November 21, 2004 (United States Geological 

Survey, 2004). 

This report begins with a brief description of the LIDAR technique and then outlines the data 

collected, processing required, and results for three study areas located within the Grand Canyon. 

Specifically, studies were performed at the Mile 30 Sand Bar, at Vaseys Paradise (Mile 32), and at the 

Mile 66 Palisades Archaeological Site (Figure 1). Conclusions and recommendations for utilizing 

terrestrial LIDAR for future studies at each of these sites are also included.

US89A 

US89 

Lees Ferry

South Rim 

Mile 30 Sand Bar 

Vaseys Paradise (Mile 32) 

Mile 66 Palisades Site 

Little Colorado 

River 

Colorado River 

Lake 

Powell 

Utah

Arizona 

0 35 km 

Figure 1. Location map of terrestrial LIDAR studies within Grand Canyon National Park 

during the November 2004 High Flow Experiment 

2
Methodology 

The terrestrial LIDAR technique, or 3D laser scanning as it is commonly known, consists of 

sending and receiving laser pulses to build a point file of three-dimensional coordinates of virtually any 

surface. The time of travel for a single pulse reflection is measured along a known trajectory such that 

the distance from the laser, and consequently the exact location of a point of interest can be computed. 

In addition, some lasers use a color sensor to obtain additional visual data on points located both within 

and outside of laser range. Given the rapid rate of data collection from the newest state of the art 

topographic laser scanning systems, the location of up to 12,000 surface points can be collected in one 

second. Thus, an entire surface, be it a building, a cliff face, or a sand bar can be surveyed quickly and 

accurately. The point file from a given scan is typically transformed into a three-dimensional surface so 

that cross-sections and volumetric calculations can be performed between consecutively scanned 

surfaces. 

The technique has been utilized by the authors successfully in a wide range of environments, 

most recently for studies involving coastal bluff change along the California coast (Collins and Sitar, 

2002, 2004, 2005), in earthquake reconnaissance studies (Kayen and others, 2004, 2006) and in the 

failure analysis of the New Orleans levee system during Hurricane Katrina (Collins and Kayen, 2005). 

Complete details of the laser scanning process can be found in these references. 

In this study, the CMG’s Riegl Z210 laser scanner was utilized as a tripod mounted survey 

instrument (Figure 2) and transported to each Grand Canyon site by raft. The laser was set up over 

various locations and survey control was obtained from existing benchmarks using traditional total 

station survey techniques. Each laser scan collected data at a rate of 8000 points per second, scanning a 

range of 336 degrees in the horizontal direction and plus and minus 40 degrees from the horizontal in 

3
the vertical direction. Multiple scans were collected to fill in “shadow zones” of locations not directly 

in the line of sight of the laser and to expand the range and density of the point data. 

Processing of the data was performed using the I-SiTE software program (I-SiTE, 2005) 

specifically designed to handle laser scanning data. Specific details of the processing procedures used 

in each location are provided with each locations summary. Metadata for the data collection effort and 

data products is available at http://walrus.wr.usgs.gov/infobank/r/r104gc/html/r-1-04-gc.meta.html

(United States Geological Survey, 2004). 

Figure 2. The USGS Coastal and Marine Geology program’s terrestrial LIDAR unit. 

4
Mile 30 Sand Bar 

Background 

The Mile 30 Sand Bar site was selected for detailed study by the GCMRC as a test location for 

obtaining high resolution topographic data of sand bars (Figure 3). Topographical surveys of sand bars 

are typically performed using standard survey methods involving personnel occupying and collecting 

data points on the sand bar itself. This type of technique generally leads to topographic changes to the 

surface by footprints as well as disturbances to steep, easily erodible slopes. The purpose of data 

collection using the laser scanning technique was therefore to test a less invasive method of surveying in 

this type of setting. Additionally, testing was performed to obtain information on the optimal location 

and number of scans required for full creation of sand bar digital terrain models along other portions of 

the Colorado River. 

Data 

A total of seven laser scans were collected of the Mile 30 Sand Bar area. For five of these scans, 

the laser was located on the sand bar itself; two other scans were collected from rock outcrops located 

across the river from the sand bar (Figure 4). These sand bar and cross-river scan sets each provided a 

data set for processing and comparison. 

Standard field survey methods were also implemented by the GCMRC to obtain survey control 

at the Mile 30 site. A total station and prism reflectors collected precise survey data for the five laser 

set-up locations on the sand bar, in addition to several survey control points and back-sight points for 

data rectification (Table 1). No control points were collected on the cross-river laser set-up locations. 

Horizontal survey coordinates are referenced to the NAD83 metric datum, with an Arizona Central 

Zone 0202 State Plane projection. Vertical survey data is referenced to the NAVD88 datum.

5
Table 1. Survey Control for Mile 30 Sand Bar 

Control 

Point Northing (m) Easting (m) Ground 

Elev. (m) 

Instrument 

Height (m) 

Instrument 

Elev. (m) 

m30lsu1 611760.814 219555.120 856.418 1.820 858.238

m30lsu2 611785.650 219539.469 856.888 1.820 858.708

m30lsu3 611767.555 219523.297 860.963 1.820 862.783

m30lsu4 611747.468 219537.323 857.333 1.820 859.153

m30lsu5 611721.384 219519.959 856.463 1.820 858.283

m30lsu6 N/A1 N/A1 N/A1 N/A1 N/A1

m30lsu7 N/A1 N/A1 N/A1 N/A1 N/A1

beachtemp 611766.208 219563.059 855.907 1.939 857.846 

new1 611753.346 219509.750 862.994 1.461 864.455

new2 611830.986 219556.016 858.307 N/A2 N/A2

Horizontal datum is NAD83 metric. Horizontal projection is Arizona Central Zone 0202 State Plane. 

Vertical datum is NAVD88.

1

 Points were not surveyed during data acquisition.

2

 Point could not be located in the scan data and instrument height was not measured in the field. 

Given the close proximity of the laser scans to one another, extremely high resolution 

topographic data was collected at this site. As an example, the scanner collected and resolved footprints 

made on the surface of the sand bar (Figure 5). A complete view of the majority of the raw data at the 

site is shown in Figure 6. As discussed, an additional capability of the laser system is its ability to

obtain background visual information on features out of range of the scanner. The photographic color 

sensor collects the color value and intensity of these background points (termed “sky points”) providing 

useful data for surface orientation. In Figure 7, two views of the raw laser scan data along with the 

background color information are shown and highlight this type of data. 

6
Figure 3. The Mile 30 Sand Bar Site. 

beachtemp

0 50 meters 

Mile 30.8

Mile 30.7 new2

new1 

m30lsu7

m30lsu6

m30lsu1 

m30lsu2 

m30lsu3

m30lsu4 

m30lsu5

Figure 4. Mile 30 Sand Bar Site showing locations of laser set-up points (triangles) and 

survey control points (circles). 

7
tripod set-up

footsteps

Figure 5. Laser scan data of Mile 30 Sand Bar showing footsteps and tripod control point 

setup. Black area indicates area where no data was collected beneath the tripod and outside 

of the 336° data collection area of the laser. 

trees 

tripod 

Figure 6. Point cloud data of Mile 30 Sand Bar showing trees and survey features. 

8
sky points

laser data 

(a) 

sky points

laser data 

(b) 

Figure 7. Mile 30 Sand Bar showing both laser data and “sky points” of background (nonlaser) data. 

9
Processing

Processing of each data set was performed using identical methods. A step by step outline of 

this methodology for the five sand bar collected scans is outlined here for reference. Each scan was 

initially surface registered to one another using the entire point cloud from each scan. Typical rootmean squared (RMS) error calculated between data point sets was on the order of 10 centimeters. Each 

scan was then filtered to a minimum point separation of 25 centimeters and a topographical 

triangulation was created from each scan. Scan Number 1 provided the best overall coverage of the site, 

thus each scan was registered to the triangulation for this scan resulting in a typical RMS error of 4 

centimeters. Each of the remaining triangulations were then recreated from the newly matched scan 

data sets and surface registered to the Scan Number 1 triangulation. This improved the RMS error 

estimate to approximately 1 centimeter which was deemed a sufficiently tight fit for the collected scan 

data. 

Each topographic triangulation was then merged with a neighboring triangulation resulting in a 

final fused topographic triangulation for the entire data set. The final surface consists of approximately 

238,000 triangular facets with 121,000 points describing a surface area of 4,200 square meters. Two 

views of the completed final surface are shown in Figure 8. 

Data georeferencing was performed by registering the collected survey data to control point 

reflectors and laser scan set-up points identified in the scan data. In total, 7 points could be identified 

out of a possible 8 control points (5 laser set-up locations, 2 fixed control points, and 1 temporary 

control point) Fixed control point “new2” could not be identified in the scan data. All scans and 

surfaces created from processing were moved to match the real-world coordinates of the surveyed 

control points. An initial fit of 44 centimeters was obtained using all 7 points, however a final fit of 8.5 

centimeters was obtained using only 5 of the control points. The improvement of the fit was likely due 

10
to the removal of points with inherent survey errors, such as inaccurate measurement of tripod height or 

misrepresentation of the survey target. 

An identical methodology was applied to the cross-river scans. Here, only two scans were 

collected from rock outcrops on the east side of the river. Topographical surface registration error for 

the two scans was calculated to be 5 centimeters with the final fusion surface consisting of 205,000 

facets with 105,000 points describing a surface area of 3,300 square meters. The slightly smaller 

surface area calculated with the cross-river scans represents only the exclusion of some of the higher 

cliff data; the entire sand bar area of interest was obtained using the cross-river scans. Georeferencing 

of the scan and surface data to real world coordinates could not be performed using the control point 

method since only one control point was visible in the scan data and precise survey data was not 

collected for the cross-river scanner origins. Instead, georeferencing relied on performing a surface 

registration from the cross-river fusion surface to the sand bar fusion surface. A final RMS error of 4.4 

centimeters was obtained using this process. This type of registration could also have been performed 

on any area of scan data that overlaps with the cross-river scan. For example, for future surveys, an area 

of cliff located above the sand bar could just as easily be utilized for the registration process given an 

initial georeferenced data set. 

Results 

The end result of the processing for the sand-bar collected scans was an individual scan fit of 1 

centimeter between data sets and a georeferenced fit of 8.5 centimeters error to the surveyed 

coordinates. The final topographic surface consists of 238,000 triangular facets and provides a high 

resolution DTM of the Mile 30 sand bar area. 

The cross-river collected scans resulted in an individual scan fit of 5 centimeters between data 

sets and a georeferenced fit of 4.4 centimeters error relative to the sand bar georeferenced fit. The final 

11
topographic surface using these two scans consists of 205,000 triangular facets and also provides a high 

resolution DTM of the Mile 30 Sand Bar. 

The final surfaces for each scan set are nearly identical and can best be compared using crosssections taken along the axis of the river. A total of 12 sections were cut along the length of the sand 

bar at 10 meter intervals (Figure 9), four of which are shown in Figure 10. The sections show an almost 

identical match to one another, and prove the utility of the lower impact cross-river scan methodology 

for characterizing the overall sand bar morphology. Only in areas higher up the sand bar, at the 

intersection of the bar with the cliff debris slope, are discrepancies found between the two data sets. In 

these areas, the discrepancies are related to a combination of dense vegetation and low-angle, oblique 

laser reflections from the cross-river scans. If the upper, fringe sections of sand bars are shown to be 

important for geomorphologic studies, additional, closer scans may be necessary, or additional vantage 

points from higher cross-river platforms may be utilized to scan these areas in higher detail. 

Conclusions and Recommendations

The Mile 30 Sand Bar data shows the utility of the terrestrial LIDAR scanning method for 

performing surface generation of complex and evolving topography. Here, two methods were utilized 

comprising near-range and far-range data acquisition. Given that the two data sets are within an order 

of magnitude of each other for scan and georeference fit error, we feel that the extra effort of collecting 

scans from the sand bar itself is not worth the additional effort. The cross-river data set provides the 

necessary data for generating accurate, high-resolution cross sections and can be used in volumetric 

calculations when future data sets are collected. Georeferencing of future data sets can be performed 

using either the surface registration techniques outlined in this report, or by conventional survey control 

of each scanner location along with at least one additional survey point located on the opposite side of 

the river. 

12
Future scans of sand bar topography in other areas of the Grand Canyon can therefore be 

performed from outcrops of rock located across river from the target sand bar. This will lessen the 

impact of foot traffic to the sand bars and will result in more efficient data acquisition trips in the Grand 

Canyon. 

862m

860m

858m

856m

Colorado River 

(a) 

862m

860m

858m

856m

(b) 

Colorado River 

Figure 8. Views of final DTM surface of Mile 30 Sand Bar from the sand bar scan set (labels 

indicate location of control points). One-meter contour elevations are shown relative to 

NAVD88. 

13
Figure 9. Location of cross sections at the Mile 30 Sand Bar site. 

14
m 

Cross section distance (meters)

m 

Cross section distance (meters)

m 

Cross section distance (meters)

m 

Cross section distance (meters)

Note: Vertical datum is referenced to NAVD88. 

Figure 10. Selected cross sections of the Mile 30 Sand Bar. Both sand bar (blue) and 

cross-river (green) data sets are shown, but appear as one line due to the nearly identical 

surface matching that was obtained. Arrows delineate upper slope discrepancies in and near 

vegetation. 

15
Vaseys Paradise (Mile 32) 

Background 

Vaseys Paradise is located approximately 1.5 miles below the Mile 30 Sand Bar (Figure 1) and 

is an oasis along the Colorado River, with dense vegetation and waterfalls emanating from the upper 

cliff faces (Figure 11). The area hosts a federally listed endangered species of snail (Kanab ambersnail) 

and is therefore a highly sensitive habitat when considering the impacts of an artificial high flow 

experiment. Since the predicted high-water line from the experimental high flow was predicted to reach 

the level of the snail habitat, biological researchers with the GCMRC were tasked with temporarily 

transplanting snails and their habitat to above the high water line. We collected several scans of the area 

to test the ability of the LIDAR unit to collect baseline habitat data for the biological researchers. 

Data 

Two scans were collected of the Vaseys Paradise area (Figure 12) consisting of 2.9 million data 

points (Figure 13). Scans were performed with the full 336° horizontal range of the scanner providing 

detailed point coverage of both sides of the canyon. While reflections were obtained from topography 

at the full 350 meter range of the scanner, the vertical range of collected data was limited by the height 

and narrowness of the canyon. However, this still allowed laser data returns from cliff faces located 

some 100 meters above the river (Figure 13). 

Processing 

The two data scans were registered to one another by a surface registration algorithm. This 

provided a full data coverage of the river right side of the canyon, with few data gaps. Since survey data 

was not obtained on the scanner origins or other control points, georeferencing was not performed on 

this data set. Each point set was first filtered to a minimum point separation of 0.5 meters, then built 

16
into a spherical triangulation. The two triangulations were then merged using a fusion surface algorithm

which resulted in the finished digital terrain surface of the area (Figure 14). 

Results 

The fusion surface provides a high resolution surface of the Vaseys Paradise area and can be 

utilized for topographic measurements or as a vertical base map of the area. Additionally, the surface 

can be compared with future laser scans to calculate any topographical changes to the area if needed. 

Perhaps the most interesting utility of the laser scan data for this location is in distinguishing areas of 

habitat removed during the high flow experiment. At the time of scanning, an area approximately 230 

m

2

 in size was identified as habitat that had been removed (Figure 15). 

Conclusions and Recommendations

The laser scanning technique shows much promise for use in documenting changes in habitat 

area for biological resources inventories. Personnel from the biological group should be consulted to 

identify other possible uses of the technique and to verify if the data collected is worth the process of 

data acquisition. 

Studies of cliff change can also be performed using this data, as necessary. Detecting cliff 

change is a standard use of the laser for the CMG team and processing of this type of data is well 

understood and has been implemented by the team members in many settings (Collins and Sitar, 2004). 

17
Figure 11. Vaseys Paradise with laser scanning equipment in foreground. 

Mile 32

0 100 meters 

Location 

of LIDAR 

scans

Mile 32.1

Mile 32.2

Vaseys 

Paradise 

Figure 12. Vaseys Paradise (Mile 32) site map showing LIDAR scan locations. 

18
Waterfalls 

100 m

Raft

Figure 13. Composite scan data for Vaseys Paradise. 

100 m

Vaseys Paradise 

Figure 14. Completed fusion surface of Vaseys Paradise cliff topography. 

19
Raft

Area of 

habitat 

removal 

(~230m2

) 

Figure 15. Vaseys Paradise data showing area of Kanab Ambersnail habitat removed prior 

to high flow experiment. 

Palisades Arroyo Archaeological Site (Mile 66) 

Background 

The Palisades Arroyo Archaeological Site comprises a location within the Grand Canyon 

containing artifacts of historical native populations. At least two arroyos (intermittent drainages, dry 

throughout most of the year) cut across the Palisades site and often reveal artifacts as they excavate 

through existing surficial soils. A goal of the GCMRC is to monitor the down cutting of the existing 

20
arroyos to determine their rate of retreat upslope into existing archaeological sites. The CMG LIDAR 

team was tasked with collecting as much data as possible in this location to determine the applicability 

of the technique in this type of setting. 

Data 

Data collection in the Palisades area was extremely difficult due to two primary factors. First, 

the site is relatively flat and does not lend itself easily to a terrestrial based approach. We found few 

locations where the standard range of the scanner (~500 meters) could be utilized. These are typically 

locations that are either perched below or above the object of interest to be scanned. In some locations, 

a small area could be scanned, but this typically covered only a 10 meter by 20 meter area. The second 

factor limiting data collection was the presence of dense vegetation. The vegetation at the site was 

typically 2 to 3 meters in height which was just higher than the scanner when set on a tripod, limiting 

the range of the laser pulses. Additionally, the denseness of the vegetation limited data collection of the 

ground farther than a few meters from the scanner. 

Environmental variables also limited data collection during this trip. A large storm brought 

heavy precipitation and light fog to the Palisades area on the two days that the team was in the area. 

These two weather forms are among the most limiting for ideal data collection using the terrestrial 

LIDAR technique; laser pulse returns are reflected off both water drops from precipitation and water 

vapor droplets from fog. Given these conditions, the data scans showed that only a small fraction of the 

possible data points were reflected from the ground topography. 

Finally, heavy precipitation led to problems with the battery and connection cables during the 

data collection time period. As a result, only one scan was collected and saved for data processing. The 

scan was initiated from the edge of the low-water line, near the raft landing area for the Palisades

campsite and included topographic data of the end of the southern-most arroyo at the site (Figure 16). 

21
Processing 

No processing of the scan was attempted due to the poor spatial coverage of the data. 

Results 

Images of the point cloud from the collected scan are included as Figures 17 and 18 and show 

the general quality of the data. Here, only the topography within 5 to 15 meters from the scanner origin 

was collected due to the heavy vegetation and limited flat ground sight distance. 

Conclusions and Recommendations

Despite the poor data coverage collected at the Palisades site, the terrestrial LIDAR technique 

may still be applicable for certain areas at this location. Point data was collected of a cliff face located 

several hundred meters away on the far side of the river, and may provide a promising location to locate 

the scanner for future surveys. 

The need to elevate the laser scanner to a sufficient height over the ground surface is of 

paramount importance. For future site visits, we would propose to use light-weight scaffolding to raise 

the scanner from 3 to 5 meters above the ground surface. This would result in a larger quantity of laser 

returns, while also reducing blocking effects from vegetation. As an example, in Figure 18 the 

maximum range of laser returns on nearly flat ground were approximately 13 meters using a tripod 

platform height of approximately 1.75 meters. If the laser scanner were to be positioned at a height of 3 

meters, the maximum range increases by 70% to 22 meters. 

Finally, since some problems with dense vegetation will always be encountered, we suggest that 

the LIDAR technique only be utilized for specific areas of archaeological interest that require high 

resolution positional documentation such as the footprints shown in Figure 5. Collecting data in this 

22
location for large scale, topographical model generation should only be attempted on a trial and 

experimental basis. 

0 100 meters 

Mile 66.2

Palisades 

Archaeological

Site 

Mile 66.1

Location 

of LIDAR 

scanning

Figure 16. Location of LIDAR scanning at the Palisades Site. 

23
Vegetation

Raft 

Figure 17. Palisades Site – Oblique view of unprocessed scan data showing heavy laser 

returns from vegetation. 

Raft 

Location of 

scanner

Vegetation

12.7m

Figure 18. Palisades Site – Vertical view of unprocessed scan data showing heavy laser 

returns from vegetation and limited range distance. 

24
General Conclusions 

This report has outlined the applicability of utilizing terrestrial LIDAR scanning to perform

scientific studies of sand bar morphology, biological habitat change and archaeological documentation. 

In all cases, we find the technology suitable, but with varying degree. For performing geomorphologic 

studies, the technique is perfectly suited and it is recommended that this approach be pursued in the 

future. The Mile 30 Sand Bar study has shown the efficiency of the method and the high-resolution 

results that can be obtained. For biological studies, we also find the technique applicable, but recognize 

that the primary contribution may be in two-dimensional mapping rather than three-dimensional process 

morphology. Finally, for archaeological studies, the technique shows promise, but should be reevaluated upon data collection under more favorable conditions. Selecting non-vegetated sites for 

scanning will improve upon meaningful data returns and form a more robust basis for evaluation of this 

technology for archaeological documentation and monitoring of morphological effects on these 

resources. 

Several items scheduled to be tested during this primary study were not performed and should be 

pursued upon further studies. These include studying the vegetative density along the river corridor by 

collection of continuous scans along the river banks and the applicability of night scanning for studying 

short-term sand bar morphology during future high flow (and lowering) events. 

Acknowledgments

Thanks are due to Kristin Brown of the GCMRC, Flagstaff, Arizona and Ann Gibbs of the CMG 

Group, USGS, Menlo Park, California for ground survey and organizational work associated with this 

project. Technical reviews by Ann Gibbs and Diane Minasian from the USGS CMG are also gratefully 

acknowledged. 

25
References Cited 

Collins, B.D. and Kayen, R.E., 2005. Terrestrial LIDAR Imagery of New Orleans Levees Affected by 

Hurricane Katrina, in Seed, R.B. et al, Preliminary Report on the Performance of the New Orleans 

Levee Systems in Hurricane Katrina on August 29, 2005,” Center for Information Technology 

Research in the Interest of Society (University of California – Berkeley), Submitted to the U.S. 

Senate, Committee on Homeland Security and Government Affairs, November 2, 2005, 

http://hsgac.senate.gov/_files/Katrina/preliminary report.pdf, Chapter 7. 

Collins, B.D. and Sitar, N., 2002. Monitoring of Coastal Bluffs Using 3-D Laser Scanning and 

Conventional Mapping, Eos Trans. AGU, 83(47), Fall Meet. Suppl., Abstract H12D-0953. 

Collins, B.D. and Sitar, N., 2004. Application of High Resolution 3D Laser Scanning to Slope Stability 

Studies, Proceedings of the 39th Symposium on Engineering Geology and Geotechnical Engineering, 

Butte, Montana, May 18-21, 2004, pp. 79-92. 

Collins, B.D. and Sitar, N., 2005. Monitoring of Coastal Bluff Stability Using High Resolution 3D

Laser Scanning, ASCE Geo-Frontiers Special Publication 138:- Site Characterization and Modeling, 

Remote Sensing in Geotechnical Engineering, E.M. Rathje, ed., ASCE, Austin, Texas, Jan 24-26, 

2005. 

I-SiTE Inc., 2005. “3D Laser Scanning Software”, 1 June 2005 <http://www.isite3d.com>. 

Kayen, R., Barnhardt, W., Carkin, B., Collins, B., Grossman, E., Minasian, D., and Thompson, E., 2004. 

Imaging the M7.9 Denali Fault Earthquake 2002 Rupture at the Delta River using LiDAR, RADAR, 

and SASW Surface Wave Geophysics, Poster presented for a session on Earthquakes II: Rupture 

Models and Constraints at the AGU 2004 Fall Meeting, December, 2004, San Francisco, California. 

Abstract No. S11A-0999. 

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Kayen, R., Collins, B.D., Bawden, G., and Pak, R., 2006. Earthquake Ground Deformation Analysis 

Using Scanning Laser LIDAR Technology, Proceedings of the 100th Anniversary Earthquake 

Conference, EERI, San Francisco, California, April 18-22, 2006. 

United States Geological Survey, Coastal and Marine Geology (CMG), 2004. Grand Canyon 

Topographic Change Detection from Field Activity: R-1-04-GC (topographic survey). 

http://walrus.wr.usgs.gov/infobank/r/r104gc/html/r-1-04-gc.meta.html 

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