2015 FEMA Lidar: Michigan Part 2 (Alger, Benzie, Delta, Grand Traverse, Leelanau, Mackinac, Manistee Counties)

The State of Michigan (DTMB) contracted with Sanborn to provide LiDAR mapping services for 13 counties in the State of Michigan. These counties include Alger, Allegan, Baraga, Benzie, Berrien, Delta, Emmet, Grand Traverse, Leelanau, Mackinac, Manistee, Marquette, and Van Buren. Utilizing multi-return systems, Light Detection and Ranging (LiDAR) data in the form of 3-dimensional positions of a dense set of mass points was collected for the 13 counties beginning in December 2014 through Fall 2015.

The Leica ALS70-HP (Sanborn) and ALS80-HP (subcontractor) were used to collect data for the survey campaign. Multiple airborne GPS (Global Positioning System) base stations were used in the Michigan LiDAR 2015 Project. These base stations were provided by Sanborn and subcontractors. The acquired LiDAR data was processed to all return point data. The last return data was further filtered to yield a LiDAR surface representing the bare earth.

This metadata record describes the Classified Point Cloud (LAS) for the 2015 FEMA Michigan LiDAR project. This data meets FEMA "Guidelines and Specifications for Flood Hazard Mapping Partners" and USGS Lidar Base Specification 1.0. Thirteen counties were collected in total, but separated into three parts. This record includes the counties in part 2.

This metadata record includes information about these counties:

Alger - covers approximately 936 square miles

Benzie - covers approximately 347 square miles

Delta - covers approximately 1180 square miles

Grand Traverse - covers approximately 490 square miles

Leelanau - covers approximately 375 square miles

Mackinac - covers approximately 1187 square mile

Manistee - covers approximately 557 square miles

The NOAA Office for Coastal Management (OCM) downloaded the following laz files from this USGS site

ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/ and processed the data to the Data Access Viewer (DAV) and to https:

USGS_LPC_MI_AlgerCo_2015_LAS_2017

USGS_LPC_MI_BenzieCo_2015_LAS_2016

USGS_LPC_MI_13CoDeltaC16_2015_LAS_2018

USGS_LPC_MI_GrandTraverseCO_2015_LAS_2017

USGS_LPC_MI_LeelanauCo_2015_LAS_2017

USGS_LPC_MI_MackinacCo_2015_LAS_2018

USGS_LPC_MI_ManisteeCo_2015_LAS_2017

Hydro breaklines are also available. These data are available for download at the link provided in the URL section of this metadata record. Please note that these products have not been reviewed by the NOAA Office for Coastal Management (OCM) and any conclusions drawn from the analysis of this information are not the responsibility of NOAA or OCM.

To acquire detailed surface elevation data for use in conservation planning, design, research, floodplain mapping, dam safety assessments, and hydrologic modeling. LAS data products are suitable for 1 foot contour generation. USGS LiDAR Base Specification 1.0, QL2. 24.5 cm FVA.

Project Projection, Datums and Units. Projection - State Plane Michigan Central and North. Horizontal datum - North American Datum of 1983 (NAD83 (2011)). Vertical datum - North American Vertical Datum of 1988 (NAVD88) using the latest geoid (Geoid12a) for converting ellipsoidal heights to orthometric heights. Units - intl feet

The following are the USGS lidar fields in JSON:

{

"ldrinfo" : {

"ldrspec" : "USGS Base Specification 1.0, QL2 meeting 24.5cm FVA",

"ldrsens" : "Leica ALS80",

"ldrmaxnr" : "4",

"ldrnps" : "0.65",

"ldrdens" : "1.67",

"ldradens" : "2.2",

"ldranps" : "0.71",

"ldrfltht" : "2250",

"ldrfltsp" : "135",

"ldrscana" : "32",

"ldrscanr" : "64",

"ldrpulsr" : "167",

"ldrpulsd" : "10",

"ldrpulsw" : "3",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.3",

"ldrswatw" : "1222",

"ldrswato" : "30",

"ldrcrs" : "NAD_1983_2011_State_Plane_Michigan_Central_FIPS_2112_Ft_Intl",

"ldrgeoid" : "NGS Geoid12a"

},

"ldraccur" : {

"ldrchacc" : "1.0",

"rawfva" : "0.137",

"clsfva" : "0.139",

"clscva" : "0.162",

"clssvas" : {

"svalctyp" : "Urban",

"svavalue" : "0.152"

},

"clssvas" : {

"svalctyp" : "LowVeg",

"svavalue" : "0.160"

},

"clssvas" : {

"svalctyp" : "MedVeg",

"svavalue" : "0.185"

},

"clssvas" : {

"svalctyp" : "HighVeg",

"svavalue" : "0.139"

}

},

"lasinfo" : {

"lasver" : "1.2",

"lasprf" : "1",

"laswheld" : "Withheld (ignore) points were identified in these files using class 10.",

"lasolap" : "Swath "overage" points were identified in these files by classifying to class 11.",

"lasintr" : "10",

"lasclass" : {

"clascode" : "1",

"clasitem" : "Unclassified"

},

"lasclass" : {

"clascode" : "2",

"clasitem" : "Bare-earth"

},

"lasclass" : {

"clascode" : "7",

"clasitem" : "All noise"

},

"lasclass" : {

"clascode" : "9",

"clasitem" : "Water"

},

"lasclass" : {

"clascode" : "10",

"clasitem" : "Ignored Ground (Breakline Proximity)"

},

"lasclass" : {

"clascode" : "11",

"clasitem" : "Withheld (overlap)"

}

}}

USGS LiDAR Base Specification 1.0, QL2. 24.5 cm FVA

The State of Michigan Geographic Information Systems digital data have been tested and their documentation carefully reviewed. However, the State of Michigan and its representatives make no warranty or representation, either expressed or implied, with respect to the digital data and their documentation, their quality, performance, merchantability, or fitness for a particular purpose. The digital data are distributed on "as is" basis, and the user assumes all risk to their quality, the results obtained from their use, and the performance of the data. In no event will the State of Michigan or its representatives be liable for any direct, indirect, special, incidental or consequential damages resulting from and defect in the State of Michigan or in their documentation. This disclaimer of warranty is exclusive and in lieu of all others, oral or written, express or implied. No agent or employee is authorized to make any modification, extension, or addition to this warranty.

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

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.

Microsoft Windows 7; ESRI ArcCatalog 9.3.1.1850

The control layout for the Michigan LiDAR 2015 project was designed in areas consisting of 2 to 4 counties each. Area 1 includes the counties of Baraga and Marquette. Area 2 includes Alger and Delta counties. Area 3 includes Mackinac and Emmet counties. Area 4 consists of Manistee, Benzie, Grand Traverse, and Leelanau counties. Area 5 includes Allegan, Van Buren, and Berrien counties.

Michigan Area 4:

The LiDAR surface was evaluated using a collection of 20 GPS surveyed checkpoints for the FVA report which compared favorably to the DEM. Attribute accuracy is tested after the LiDAR processing stage. After classification of the LiDAR data, DEMs are created using the bare earth points. The FVA, SVA, and CVA reports are generated from the comparison of the DEM and the ground control collected within the project area. The DEM surface was evaluated using a collection of 20 GPS surveyed checkpoints for the FVA report. The SVA Urban report, the SVA Low Vegetation report, the SVA Medium Vegetation report, the SVA High Vegetation report, and the CVA report are generated from the comparison of the DEM and the ground control collected within the project area.

Horizontal positional accuracy is dependent upon the quality of the GPS/INS solution, sensor calibration and ground conditions at the time of data capture. The standard system results for horizontal accuracy meet or exceed the project specified 1.0 meter RMSE. This value is computed by comparing ground control to a DEM derived from the classified LiDAR data and represents the RMSE of residuals on controls within the project area.

For the DEM data derived from the classified point cloud, the FVA, SVA, and CVA were computed. The vertical accuracy was tested with independent survey check points distributed throughout various terrain types. These check points were not used in the calibration or post processing of the lidar point cloud data. These points were surveyed using static GPS base stations collecting point location for 20 minute intervals. Elevations were measured for the x,y,z location of each check point. Elevations interpolated from the DEM surface were then compared to the elevation values of the surveyed control. AccuracyZ has been tested to meet 9.25 cm Fundamental Vertical Accuracy at 95 Percent confidence level using RMSE(z) x 1.9600 as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using National Digital Elevation Program (NDEP)/ASRPS Guidelines.

Benzie, Grand Traverse, Manistee, Marquette Counties (Area 4)

FVA

0.071 m RMSE or 0.139 m FVA @ 95th Percentile in open terrain

Tested using 20 independent survey check points distributed throughout flat terrain types

CVA

0.088 m RMSE or 0.162 m CVA @ 95th Percentile using all FVA and SVA class checkpoints (CVA)

Tested using 100 independent survey check points distributed throughout various terrain types. These points contained all FVA and SVA class points.

SVA

0.082 m RMSE or 0.152 m SVA @ 95th Percentile - Urban Terrain Types

Tested using 20 independent survey check points

0,088 m RMSE or 0.160m SVA @ 95th Percentile - Low Vegetation Terrain Types

Tested using 20 independent survey check points

0.109 m RMSE or 0.185m SVA @ 95th Percentile - Medium Vegetation Terrain Types

Tested using 20 independent survey check points

0.085 m RMSE or 0.139m SVA @ 95th Percentile - High Vegetation Terrain Types

Tested using 20 independent survey check points

Alger, Delta Counties (Area 2)

FVA

0.055m RMSE or 0.108m FVA @ 95th Percentile in open terrain

Tested using 22 independent survey check points located in flat terrain types.

CVA

0.107m RMSE or 0.209m CVA @ 95th Percentile using all FVA and SVA class checkpoints (CVA)

Tested using 80 independent survey check points located in various terrain types.

SVA

0.077m RMSE or 0.122m SVA @ 95th Percentile - Low Vegetation Terrain Types

Tested using 18 independent survey check points

0.122m RMSE or 0.301m SVA @ 95th Percentile - Medium Vegetation Terrain Types

Tested using 21 independent survey check points

0.095m RMSE or 0.162m SVA @ 95th Percentile - High Vegetation Terrain Types

Tested using 19 independent survey check points

Mackinac County (Area 3)

FVA

0.041m RMSE, or 0.080 FVA @ 95 percent confidence level in open terrain

Tested using 20 independent survey check points located in flat terrain types.

CVA

0.076m RMSE, or 0.139m CVA @ 95th Percentile using all FVA and SVA class checkpoints.

Tested using 81 independent survey check points located in various terrain types.

SVA

0.077m RMSE, or 0.133m SVA @ 95th Percentile - Low vegetation Terrain Types

Tested using 20 independent survey check points

0.093m RMSE, or 0.143m SVA @ 95th Percentile - Medium Vegetation Terrain Types

Tested using 20 independent survey check points

0.083m RMSE, or 0.179m SVA @ 95th Percentile - High Vegetation Terrain Types

Tested using 21 independent survey check points

LiDAR data is collected for the project area. Post processing of the simultaneously acquired GPS/INS is performed and applied to the laser returns to output a point cloud in the specified project coordinate system and datums. The point cloud data is then subjected to automated classification routines to assign all points in the point cloud to ground, water, overlap and unclassified point classes. Anomalous laser returns that occur infrequently are removed entirely from the data set. Once clean bare earth points are established, DEMs are created using bare earth points and hydro features. The DEM surface is then compared to the survey checkpoints. These accuracies must pass the Fundamental Vertical Accuracy, Supplemental Vertical Accuracy, and Consolidated Vertical Accuracy specifications.

LiDAR data is collected within the project area and processed. After the DEMs were created, the dataset was verified against control.