Joshua B. Logan
Alexander G. Snyder
2017
Terrestrial lidar data from northern Monterey Bay, California, March 2015
comma-delimited text
data release
DOI:10.5066/F76H4GCW
Pacific Coastal and Marine Science Center, Santa Cruz, California
U.S. Geological Survey
https://doi.org/10.5066/F76H4GCW
https://www.sciencebase.gov/catalog/file/get/59e0ed15e4b05fe04cd00030
Andrew W. Stevens
Joshua B. Logan
Alexander G. Snyder
Daniel J. Hoover
Patrick L. Barnard
Jonathan A. Warrick
2017
Beach topography and nearshore bathymetry of northern Monterey Bay, California
data release
DOI:10.5066/F76H4GCW
Santa Cruz, CA
U.S. Geological Survey
https://doi.org/10.5066/F76H4GCW
This part of the data release presents topography data from northern Monterey Bay, California collected in March 2015 with a terrestrial lidar scanner.
Data were obtained to document changes in shoreline position and coastal morphology as they relate to episodic (storms), seasonal, interannual, and longer (for example, El NiƱo) processes. These data are intended for science researchers, students, policy makers, and the general public. These data can be used with geographic information systems or other software to identify topographic and shallow-water bathymetric features.
Additional information about the field activities from which these data were derived are available online at:
http://cmgds.marine.usgs.gov/fan_info.php?fan=2015-625-FA
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
20150318
20150319
ground condition at time data were collected
Not planned
-122.025434
-121.949031
36.972051
36.959790
USGS Metadata Identifier
USGS:59e0ed15e4b05fe04cd00030
USGS Thesaurus
topography
LIDAR
ISO 19115 Topic Category
elevation
Data Categories for Marine Planning
Bathymetry and Elevation
Marine Realms Information Bank (MRIB) keywords
coastal sediment budget
Global Change Master Directory (GCMD)
GPS (Global Positioning System)
None
U.S. Geological Survey
USGS
Coastal and Marine Geology Program
CMGP
Pacific Coastal and Marine Science Center
PCMSC
Geographic Names Information System (GNIS)
Pacific Ocean
Monterey Bay
Monterey County
Santa Cruz County
none
USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey as the originator(s) of the dataset and in products derived from these data. This information is not intended for navigational purposes.
Joshua B. Logan
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Physical Scientist
mailing and physical
2885 Mission St.
Santa Cruz
CA
95060
USA
831-460-7519
jlogan@usgs.gov
No formal attribute accuracy tests were conducted.
All data falls within expected ranges.
Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details.
Because the terrestrial lidar scanner rotates around the vertical axis during data collection, horizontal errors in the collected measurements are dependent on the range of each measurement from the sensor. To limit errors caused by long-range returns, only measurements within a range of 700 meters of each scan position were used for the final data product. Typical registration errors in the horizontal angle reported during point cloud registration for these data were found to be below 0.01 degrees, suggesting a maximum horizontal error of about 1.7 cm at a range of 100 meters, up to 12.2 cm at 700 meters. Because the majority of measurements in each point cloud are made near the scanner, it is estimated that average horizontal accuracy of the measurements is less than 7 cm (equivalent to 0.01 degrees of error at range of 400 meters).
The vertical accuracy of the terrestrial lidar data was tested by comparing the final cleaned point cloud elevation values to concurrently collected topographic GNSS data. The RMS errors calculated for the vertical differences between these data and the point cloud data were typically found to be less than or equal to about 7 cm.
Terrestrial lidar data was collected between March 18 and 19, 2015 using a tripod-mounted Riegl VZ-1000 lidar scanner. For each area surveyed, the scanner was placed at several positions which were selected to provide maximum line-of-sight coverage of the area of interest. Scans were typically conducted in panoramic mode, creating a detailed point cloud of all unobstructed surfaces in a 360 degree view of the scanner. Each individual scan typically contains 20 million or more precise point measurements. At each scan position, co-registered photographic imagery was also collected with a scanner mounted DSLR camera. Scanner registration was performed by placing four or more cylindrical or flat reflective tripod-mounted targets in view of the scanner. The positions of these reflectors were measured using survey grade GNSS, and used in post-processing to register each point cloud into a projected coordinate system.
20150319
Initial data processing of the terrestrial lidar data was conducted using Riegl RiscanPro software. Each scan position and point cloud was registered using the GNSS-measured positions of the tripod-mounted reflectors. The quality of the registration was visually compared against adjacent registered point clouds, and concurrently collected topographic GNSS data. In the unlikely case that initial registration appeared to be inaccurate either due to poor GNSS precision, or poor reflector geometry, a point cloud fitting process called 'Multi-Station Adjustment (MSA)' was used to adjust the spatial registration to match adjacent point clouds. After registration was completed, the point clouds were colorized using RGB pixel values from the co-registered photographic imagery. The point clouds were then hand-edited to remove erroneous data points below the true ground surface caused by reflections on wet sand or water. Additional noise from water, breaking surf, haze, and objects within the point cloud were also removed by hand editing. The point clouds were then exported to comma delimited (.csv) format and converted into LAS format and processed using the LAStools software suite. A batch script was used to: 1) clip the LAS files to the areas of interest, 2) perform a range filter to remove all points further than 700 meters away from the scanner, 3) thin the point cloud to an average spacing of 5 centimeters to reduce point density, and 4) perform a classification algorithm to detect ground points and remove objects and vegetation from the point cloud. At this point a final visual check on the remaining points was performed to verify and correct any misclassification of ground surfaces. To produce the final output files all classified ground points were thinned using the lowest elevation point in 10 centimeter cells, and the resulting points were exported to a comma delimited (.csv) format.
20171015
Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed.
20201019
U.S. Geological Survey
VeeAnn A. Cross
Marine Geologist
Mailing and Physical
384 Woods Hole Road
Woods Hole
MA
02543-1598
508-548-8700 x2251
508-457-2310
vatnipp@usgs.gov
Point
Point
4549160
Universal Transverse Mercator
10
0.9996
-123.0
0.0
500000.0
0.0
row and column
0.001
0.001
Meter
NAD83 (2011)
GRS_1980
6378137.0
298.257222101
North American Vertical Datum of 1988
0.001
meters
Explicit elevation coordinate included with horizontal coordinates
Attribute Table
Table containing attribute information associated with the dataset
Producer defined
x
East coordinate of data point relative to the North American Datum of 1983 (2011 realization), projected in the Universal Transverse Mercator (UTM), Zone 10 North, meters, coordinate system
Producer Defined
586759.360
593547.007
meters
y
North coordinate of data point relative to the North American Datum of 1983 (2011 realization), projected in the Universal Transverse Mercator (UTM), Zone 10 North, meters, coordinate system
Producer defined
4090855.612
4092287.818
meters
z
Height in meters of data point with reference to the North American Vertical Datum of 1988.
Producer defined
-0.141
7.804
meters
R
Red pixel value from co-registered digital camera for each data point
Producer defined
0
255
unitless digital value
G
Green pixel value from co-registered digital camera for each data point
Producer defined
0
255
unitless digital value
B
Blue pixel value from co-registered digital camera for each data point
Producer defined
0
255
unitless digital value
U.S. Geological Survey - Science Base
U.S. Geological Survey
mailing and physical
Denver Federal Center, Building 810, Mail Stop 302
Denver
CO
80225
USA
1-888-275-8747
sciencebase@usgs.gov
Topography data are available as a comma-delimited text files (mb15_mar_tls_capitola.csv; mb15_mar_tls_santacruz.csv), along with associated FGDC-compliant metadata.
Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty.
comma-delimited text
Matlab 9.2.0.556344
text
comma-delimited text file
39.1
https://www.sciencebase.gov/catalog/file/get/59e0ed15e4b05fe04cd00030?name=mb15_mar_tls_capitola.csv
https://doi.org/10.5066/F76H4GCW
Data can be downloaded via the Internet
comma-delimited text
Matlab 9.2.0.556344
text
comma-delimited text file
146.8
https://www.sciencebase.gov/catalog/file/get/59e0ed15e4b05fe04cd00030?name=mb15_mar_tls_santacruz.csv
https://doi.org/10.5066/F76H4GCW
Data can be downloaded via the Internet
None
20201019
Joshua B. Logan
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Physical Scientist
mailing and physical
2885 Mission St.
Santa Cruz
CA
95060
USA
831-460-7519
astevens@usgs.gov
Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998