2022 USGS Lidar: Becker County, MN

LIDAR-derived binary (.las) files containing classified points of all returns. We have seven (7) classifications Unclassified, Ground, Low Noise, Water, Bridge Decks, High Noise and Ignore Ground. These files adhere to USGS-NGP Lidar Base Specification 2021 rev. A Quality Level 1 (QL1) standards, eight points or greater per square meter. These files are delivered in tile format (1000x1000m).

This metadata record supports the data entry in the NOAA Digital Coast Data Access Viewer (DAV). For this data set, the DAV is leveraging the Entwine Point Tiles (EPT) hosted by USGS on Amazon Web Services.

This task is for providing a spring 2022 leaf-off and snow-free lidar survey over an area of approximately 1,474.73 square miles. This project will support the 3DEP mission, the Natural Resources Conservation Service (NRCS) high-resolution elevation enterprise, as well as many state and local agencies.

USGS Task Order 140G0221F0273-MN_BeckerCounty_2021_D21

<lidar>

<ldrinfo>

<!-- Lidar Information - contains metadata about the sensor and collection conditions. When multiple instruments are used (e.g. two different instruments in a single plane), please use multiple <ldrinfo> tags to describe each individual instrument. If only one instrument was used, please delete this section. -->

<ldrspec>USGS-NGP Lidar Base Specification 2021, Revision A</ldrspec>

<!-- Lidar Base Specification applicable to the point cloud. -->

<ldrsens>Optech Galaxy T2000 Airborne Laser Terrain Mappers (ALTM) 5060475 & 5060495</ldrsens>

<!-- Lidar Sensor make and model. -->

<ldrmaxnr>8</ldrmaxnr>

<!-- Lidar Maximum Number of Returns per pulse. -->

<ldrnps>0.35</ldrnps>

<!-- Lidar Nominal Pulse Spacing, in meters. -->

<ldrdens>8</ldrdens>

<!-- Lidar Nominal Pulse Density, in points per square meter. -->

<ldranps>0.35</ldranps>

<!-- Lidar Aggregate Nominal Pulse Spacing, in meters. -->

<ldradens>8</ldradens>

<!-- Lidar Aggregate Nominal Pulse Density, in points per square meter. -->

<ldrfltht>2000</ldrfltht>

<!-- Lidar Flight Height for the collection, in meters. -->

<ldrfltsp>170</ldrfltsp>

<!-- Lidar Nominal Flight Speed for the collection, in knots. -->

<ldrscana>35</ldrscana>

<!-- Lidar Sensor Scan Angle, total, in degrees. -->

<ldrscanr>120</ldrscanr>

<!-- Lidar Scan Frequency of the scanner, in hertz. -->

<ldrpulsr>1600</ldrpulsr>

<!-- Lidar Pulse Rate of the scanner, in kilohertz. -->

<ldrpulsd>3.5</ldrpulsd>

<!-- Lidar Pulse Duration of the scanner, in nanoseconds. -->

<ldrpulsw>1</ldrpulsw>

<!-- Lidar Pulse Width of the scanner, in meters. -->

<ldrwavel>1064</ldrwavel>

<!-- Lidar Central Wavelength of the sensor laser, in nanometers. -->

<ldrmpia>1</ldrmpia>

<!-- Lidar Multiple Pulses In Air, 0 = No; 1 = Yes -->

<ldrbmdiv>0.25</ldrbmdiv>

<!-- Lidar Beam Divergence, in Milliradians. -->

<ldrswatw>1261</ldrswatw>

<!-- Lidar Swath Width on the ground, in meters. -->

<ldrswato>20</ldrswato>

<!-- Lidar Nominal Swath Overlap, as a percentage. -->

<ldrgeoid>National Geodetic Survey (NGS) Geoid18</ldrgeoid>

<!-- Geoid used for vertical reference. -->

</ldrinfo>

<ldraccur>

<!-- Lidar Accuracy. Non-vegetated vertical accuracy values for the swath. ALL VALUES ARE REPORTED IN METERS. -->

<ldrchacc>0.0</ldrchacc>

<!-- Lidar Calculated Horizontal Accuracy of the point cloud data. -->

<rawnva>0.0</rawnva>

<!-- Raw Nonvegetated Vertical Accuracy of the raw point cloud data. -->

<rawnvan>0</rawnvan>

<!-- Raw Nonvegetated Vertical Accuracy Number of checkpoints used to calculate the reported nonvegetated vertical accuracy of the raw point cloud data. -->

<!-- Classified Non-vegetated Vertical Accuracy. The calculated nonvegetated vertical accuracy of the classified point cloud data (required if available). Type: decimal number. -->

<!-- Classified Non-vegetated Vertical Accuracy Number of checkpoints. The number of check points used to calculate the reported nonvegetated vertical accuracy of the classified point cloud data. Type: real number. -->

<!-- Classified Vegetated Vertical Accuracy. The calculated vegetated vertical accuracy of the classified point cloud data (required if available). Type: decimal number. -->

<!-- Classified Vegetated Vertical Accuracy Number of checkpoints. The number of check points used to calculate the vegetated vertical accuracy of the classified point cloud data. Type: real number. -->

</ldraccur>

<lasinfo>

<!-- LAS Information. Type: compound. -->

<lasver>1.4</lasver>

<!-- LAS Version -->

<lasprf>6</lasprf>

<!-- LAS Point Record Format. -->

<laswheld>Withheld (ignore) points were identified in these files using the standard LAS withheld bit.</laswheld>

<!-- Describe how withheld points are identified. -->

<lasolap>Swath "overage" points were not identified in these files using the standard LAS overlap bit.</lasolap>

<!-- Describe how overage points are identified. -->

<lasintr>12</lasintr>

<!-- Specify the native radiometric resolution of intensity values, in Bits. -->

<lasclass>

<!-- LAS Classification. Type: compound. -->

<clascode>1</clascode>

<!-- Classification Code -->

<clasitem>Unclassified</clasitem>

<!-- Classification Item -->

</lasclass>

<lasclass>

<!-- LAS Classification. Type: compound. -->

<clascode>2</clascode>

<!-- Classification Code -->

<clasitem>Ground</clasitem>

<!-- Classification Item -->

</lasclass>

<lasclass>

<!-- LAS Classification. Type: compound. -->

<clascode>7</clascode>

<!-- Classification Code -->

<clasitem>Low Noise</clasitem>

<!-- Classification Item -->

</lasclass>

<lasclass>

<!-- LAS Classification. Type: compound. -->

<clascode>9</clascode>

<!-- Classification Code -->

<clasitem>Water</clasitem>

<!-- Classification Item -->

</lasclass>

<lasclass>

<!-- LAS Classification. Type: compound. -->

<clascode>17</clascode>

<!-- Classification Code -->

<clasitem>Bridge</clasitem>

<!-- Classification Item -->

</lasclass>

<lasclass>

<!-- LAS Classification. Type: compound. -->

<clascode>18</clascode>

<!-- Classification Code -->

<clasitem>High Noise</clasitem>

<!-- Classification Item

</lasclass>

<lasclass>

<!-- LAS Classification. Type: compound. -->

<clascode>20</clascode>

<!-- Classification Code -->

<clasitem>Ignore Ground</clasitem>

<!-- Classification Item -->

</lasclass>

</lasinfo>

</lidar>

Any conclusions drawn from the analysis of this information are not the responsibility of NOAA, the Office for Coastal Management or its partners.

To the extent possible under law, the U.S. Government has waived all copyright and related or neighboring rights to this dataset.

Data is available online for bulk and custom downloads.

None

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.

The lidar data set was produced to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 20 (cm) RMSEx / RMSEy Horizontal Accuracy Class which equates to Positional Horizontal Accuracy = +/- 49 cm at a 95% confidence level.

This data set was produced to meet ASPRS Positional Accuracy Standard for Digital Geospatial Data (2014) for a 10-cm RMSEz Vertical Accuracy Class.

USGS Determined Vertical Accuracy:

Non-Vegetated Vertical Accuracy (NVA) = 3.65 cm RMSE

Vegetated Vertical Accuracy (VVA) = 13.56 cm at 95th Percentile

These LAS data files include all data points collected. No points have been removed or excluded. A visual qualitative assessment was performed to ensure data completeness. No void areas or missing data exist. The raw point cloud is of good quality and data passes Non-Vegetated Vertical Accuracy specifications.

Data covers the entire area specified for this project.

The NOAA Office for Coastal Management (OCM) ingested references to the USGS Entwine Point Tiles (EPT) hosted on Amazon Web Services (AWS) into the Digital Coast Data Access Viewer (DAV). The DAV accesses the point cloud as it resides on AWS under the usgs-lidar-public-container.