2010 ARRA Lidar: Allendale County (SC)

Provide high density LiDAR elevation data map of Allendale County, SC. Provide Bare Earth DEM (vegetation removal) of Allendale County, SC.

This LIDAR operation was designed to provide a high density set of masspoints within the defined areas. The data sets are suitable for the development of contours for use in hydraulic/hydrologic model development, and for assessing environmental impacts.Typical uses for the data set include: FEMA Flood Plain Map Modernization. DFIRM map updates. Watersheds and other hydro studies per FEMA specifications. County Mapping projects which include several uses, in addition to Flood mitigation assessment. Mapping projects that include accuracy verification, reporting and meta data.

10630

The lidar report for this data set may be viewed at: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/4801/supplemental/sc2010_arra_allendale_m4801_lidarreport.pdf

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

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/4801/supplemental/sc2010_arra_allendale_m4801.kmz

None planned

LAS 1.2

See process steps within this metadata record for specific methodology

Any conclusions drawn from the analysis of this information are not the responsibility of Sanborn, SC DNR, 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=4801

The data set is dynamically generated based on user-specified parameters;

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be aware that temporal changes may have occurred since this data set was collected and some parts of this data may no longer represent actual surface conditions.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. These data depict the heights at the time of the survey and are only accurate for that time

This dataset is not valid without the signed and sealed copy of the Florida Minimum Technical Standards Report

of Specific Purpose Survey dated 4/31/2008. Please refer to this document for user constraints.

The flight missions were typically four or five hours in duration including runway calibration flights flown at the beginning and the end of each mission. During the data collection, the operator recorded information on log sheets which includes weather conditions, LiDAR operation parameters, and flight line statistics. Near the end of the mission GPS ambiguities are again resolved by flying within ten kilometers of the base stations, to aid in post-processing.

Table 2 shows the planned LiDAR acquisition parameters with a flying height of 1600 meters above ground level (AGL) for the Optech system on a mission to mission basis.

Federal Emergency Management Administration (FEMA) LiDAR Specifications; Quantitative Value: 1.00 meters, Test that produced the value: Processing accuracies and requirements

Federal Emergency Management Administration (FEMA) LiDAR Specifications; 15 cm RMSE; Quantitative Value: 0.15 meters, Test that produced the value: The LiDAR data was finalized by using both Bamberg County and Hampton County. The original NGS benchmarks for Allendale were not precise and sufficient enough to create a standalone accuracy assessment for this county. Instead, the entire Allendale County project was vertically shifted to meet the clients specifications. This process was completed by measuring the vertical shifts between the three counties and applying this offset to each tile in Allendale.

Complete

A minimum of two GPS base stations were set for the Allendale County project, which is within the project area or within the required baseline specifications of the project.

Pre-flight checks such as cleaning the sensor head glass are performed. A four minute INS initialization is conducted on the ground, with the engines running, prior to flight, to establish fine-alignment of the INS. GPS ambiguities are resolved by flying within ten kilometers of the base stations.