2006 U.S. Geological Survey Topographic LiDAR: Alameda County

The Light Detection and Ranging (LiDAR) data set is a survey of Alameda County in Northern California. The entire survey covers approximately 868.382 square miles.

The Nominal Point Density of this dataset is approximately 1.66 meters for unobscured areas. The LiDAR discrete-return point cloud data were originally available in the

American Society for Photogrammetry and Remote Sensing (ASPRS) LAS V1.2 format.

The data classifications available from the NOAA Data Access Viewer (DAV) are:

1 - Unclassified

2 - Ground

7 - Low point (Noise)

10 - Overlap

Original contact information:

Contact Org: U.S. Geological Survey Earth Resources Observation and Science (EROS) Center

Title: Long Term Archive (LTA) Representative

Phone: Unknown

Email: lta@usgs.gov

High-resolution digital elevation maps generated by airborne and stationary LiDAR have led to significant advances in geomorphology, the branch of

geoscience concerned with the origin and evolution of Earth's surface topography. LiDAR provides unique characteristics relative to other remotely sensed data sources

by providing three-dimensional feature information that cannot be derived from traditional imaging sensors.

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A footprint of this data set may be viewed in Google Earth at:

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/1474/supplemental/ca2006_usgs_alameda_footprint.kmz

LiDAR points in LAS 1.2 format

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Any conclusions drawn from the analysis of this information are not the responsibility

of Sanborn, USGS, NOAA, the Office for Coastal Management or its partners.

This data can be obtained on-line at the following URL:

https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=1474

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Users should be aware that temporal changes may have occurred since this data set was collected

and some parts of this data may no longer represent actual surface conditions. Users should not use

this data for critical applications without a full awareness of its limitations. These data

depict the heights at the time of the survey and are only accurate for that time.

The identification of features is provided by the distinct electromagnetic energy it emits,reflects, or otherwise transmits. This is called the spectral signature.

Other signatures such as tone (lightness or darkness), texture (surface roughness or smoothness), pattern,shadow, shape, and size are as important. Thus, through the

use of the thematic mapper sensor, such elements as water features, soils, and vegetation can be identified and distinguished from each other.

No information about the vertical accuracy was given with the original metadata. This value is assumed based on FEMA lidar specifications concerning vertical accuracy.; Quantitative Value: 0.30 meters, Test that produced the value: Accuracyz = RMSEz X 1.9600 at the 95% confidence level (meters).

The lidar collection has been acquired by the USGS through contracts, partnerships with other Federal, state, tribal, or regional agencies, from

direct purchases from private industry vendors, and through volunteer contributions from the science community. While USGS makes every effort to provide accurate and

complete information, USGS provides no warranty, expressed or implied, as to the accuracy, reliability or completeness of furnished lidar point clouds. Please note

that USGS does not control and cannot guarantee the relevance, timeliness, or accuracy of these outside materials.

All data formatted by OCM validated using commercial GIS software to ensure proper formatting and loading.