2014 Mobile County, AL Lidar

Atlantic was contracted to acquire high resolution topographic LiDAR (Light Detection and Ranging) data

located in Mobile County, Alabama. The intent was to collect one (1) Area of Interest (AOI) that

encompasses Mobile County. The total client defined AOI was 1,402 square miles or 3,361

square kilometers. The data were collected from January 12 - 22, 2014. Classifications of data available from NOAA OCM are: 1 (Unclassified, 2 (Ground), 3 (Low Vegetation), 7 (Low Noise), 8 (Model Key Points), 9 (Water), 10 (Ignored Ground, Breakline Proximity). Low vegetation points were removed as they were incorrect and not required for delivery.

Digital Elevation Models (DEMs) created from this lidar data are available for download. They are available at: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=5169 . Breaklines are available at: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/4966/supplemental/breaklines

Original contact information:

Contact Name: Scott Kearney

Contact Org: City of Mobile

Phone: (251) 208-7942

Email: kearney@cityofmobile.org

Mobile County, Alabama requires efficient data to effectively plan and manage county infrastructure. This dataset was developed to support Mobile County. The scope involved the acquisition of USGS Quality Level 2 LiDAR data to be processed, classified to produce a new countywide DEM and one foot elevation contours for the entire 1402 square mile Mobile County Project Area.

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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/geoid18/4966/supplemental/al2014_mobile_county_m4966.kmz

Reports for this data set may be viewed at:

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/4966/supplemental/al2014_mobile_county_m4966_lidarreport.pdf https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/4966/supplemental/al2014_mobile_county_m4966_surveyreport.pdf https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/4966/supplemental/al2014_mobile_county_m4966_acquisitionreport.pdf

Any conclusions drawn from the analysis of this information are not the responsibility of Atlantic, City and County of Mobile, 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=4966

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.

All work was done in coordination with Mobile County Contract. | Quantitative Value: Projection ConsistencyFile Format | Quantitative Test Explanation: Global Mapper ver.11.02 was used to validate that the correct projection information was applied to each image.Image Station Raster Utility - Display Header application was used to validate file format parameters such as:

4-band, 8-bits per band (RGBI), and pixel readout starts in northwest corner as (0,0).

LiDAR Horizontal Accuracy of the bare-earth data was assessed and reported in accordance with the guidelines developed by the NDEP and subsequently adopted by the ASPRS;; Quantitative Value: 0.095 meters, Test that produced the value: LiDAR Horizontal Accuracy (in meters) of the bare-earth data was assessed and reported in accordance with the guidelines developed by the NDEP and subsequently adopted by the ASPRS;

LiDAR Vertical Accuracy of the bare-earth data was assessed and reported in accordance with the guidelines developed by the NDEP and subsequently adopted by the ASPRS;

- FVA<= 0.60 ft ACCZ, 95% (0.30 ft RMSEZ)

- CVA<= 0.80 ft ACCZ, 95% (0.41 ft RMSEZ)

- SVA<= 0.80 ft ACCZ, 95% (0.41 ft RMSEZ)

One hundred and eleven (111) surveyed points were measured for the purpose of assessing the accuracy of the Mobile County data.

Quantitative_Horizontal_Positional_Accuracy_Assessment:

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:

Tested 0.511 US Survey Foot (0.156 m) Fundamental Vertical Accuracy (FVA) at ninety-five percent confidence level in open terrain using RMSE(z) x 1.9600. RMSEz = 7.9 cm.

Tested 0.457 US Survey Foot Consolidated Vertical Accuracy (CVA) at ninety-five percent confidence level, using RMSE(z) x 1.9600.

Tested 0.372 US Survey Foot Supplemental Vertical Accuracy (SVA) at; Quantitative Value: 0.079 meters, Test that produced the value: Tested 0.511 US Survey Foot (0.156 m) Fundamental Vertical Accuracy (FVA) at ninety-five percent confidence level in open terrain using RMSE(z) x 1.9600. RMSEz = 7.9 cm. The data meets the expected vertical accuracy of 0.6ft, @ ninety-five percent confidence level, using RMSE(z) x 1.9600,. as stated in the project contract.

Cloud Cover: 0

This data set covers the spatial extent of topographic lidar data obtained during this survey.

Topological integrity of the data was validated using the validation tools in ESRI's ArcGIS 10.1.