2018 FEMA Lidar: Region 9, CA

Product: Processed, classified lidar point cloud data tiles in LAS 1.4 format.

Geographic Extent: Approximately 10,547 square miles across 6 AOIs in California.

Dataset Description: The CA-AZ FEMA R9 Lidar lidar project called for the planning, acquisition, processing, and production of derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.7 meters. Project specifications were based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 1.2. The data was developed based on a horizontal datum/projection of NAD83 (2011) State Plane California I & IV (FIPS Zone 0401 & 0404), US Survey Feet, and a vertical datum of NAVD88 (GEOID12B), US Survey Feet. Lidar data was delivered as processed LAS 1.4 files formatted to 10,516 individual 4,500-feet x 4,500-feet tiles.

Ground Conditions: Lidar was collected in 2018 while no snow was on the ground and rivers were at or below normal levels. In order to post process the lidar data to meet task order specifications and meet ASPRS vertical accuracy guidelines, Woolpert established 148 ground control points across all California AOIs that were used to calibrate the lidar to known ground locations established throughout the project area. An additional 258 independent accuracy checkpoints (145 NVA points and 113 VVA points), were collected across all California AOIs and used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data.

High quality elevation data products are critical for riverine floodplain study and mapping for the National Flood Insurance Program. This acquisition allows FEMA Region IX to produce floodplain analysis where it is needed, to provide updates to flood insurance rate maps, and to produce floodplain administration decision support tools.

FEMA, in administration of the National Flood Insurance Program and under FEMAs Risk Mapping Assessment and Planning (Risk MAP) program, orders these elevation products to meet or exceed the quality specifications published by the US Geological Survey for acceptance into the 3-D Elevation Program (3-DEP). Data of this quality is interpreted as sufficient for floodplain engineering studies, analysis, and mapping of flood hazard.

USGS Contract No. G16PC00022 Task Order No. 140G0218F0027. CONTRACTOR: Woolpert. Sub-Contractors: Aerial Services, Inc. (ASI), Aero-Graphics, Keystone Aerial Surveys.

The following are the USGS lidar fields in JSON:

{

"ldrinfo" : {

"ldrspec" : "USGS NGP Base Specifications v1.2",

"ldrsens" : "Optech ALTM Orion H300 (Aero-Graphics)",

"ldrmaxnr" : "4",

"ldrnps" : "2.03",

"ldrdens" : "0.7",

"ldranps" : "2.03",

"ldradens" : "0.7",

"ldrfltht" : "1800",

"ldrfltsp" : "110",

"ldrscana" : "29",

"ldrscanr" : "40.3",

"ldrpulsr" : "125",

"ldrpulsd" : "3",

"ldrpulsw" : "0.9",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.25",

"ldrswatw" : "931",

"ldrswato" : "30",

"ldrgeoid" : "GEOID12B"

},

"ldraccur" : {

"ldrchacc" : "0",

"rawnva" : "0",

"rawnvan" : "0",

"clsnva" : "0",

"clsnvan" : "0",

"clsvva" : "0",

"clsvvan" : "0"

},

"lasinfo" : {

"lasver" : "1.4",

"lasprf" : "6",

"laswheld" : "Geometrically unreliable points were identified using a combination of automated and manual techniques and subsequently classified as high or low noise and given the standard Withheld bit.",

"lasolap" : "Swath "overage" points were identified in these files using the standard LAS overlap bit.",

"lasintr" : "16",

"lasclass" : {

"clascode" : "1",

"clasitem" : "Processed but not classified"

},

"lasclass" : {

"clascode" : "2",

"clasitem" : "Bare earth ground"

},

"lasclass" : {

"clascode" : "7",

"clasitem" : "Noise"

},

"lasclass" : {

"clascode" : "9",

"clasitem" : "Water"

},

"lasclass" : {

"clascode" : "10",

"clasitem" : "Ignored ground"

},

"lasclass" : {

"clascode" : "17",

"clasitem" : "Bridge Decks"

},

"lasclass" : {

"clascode" : "18",

"clasitem" : "High Noise"

}

}}

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

Data is available online for bulk or 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 10; Esri ArcCatalog v10.4; Esri ArcMap v10.4; GeoCue 2017.1.14.1; IPAS Pro v1.35; LP360 v2018.1.57.4; Leica CloudPro v1.2.4; Novatel Inertial Explorer v8.60.6129; POSPac Software v5.3; TerraMatch v18; TerraModeler v18; TerraScan v18.

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

The following VA information is from the USGS analysis. More information can be found in the supplemental section of the Bulk Download webpage.

The number of Checkpoints tested for LPC NVA : 237

The LPC NVA RMSEz= 5.15 cm

The LPC NVA Accuracy z at 95% confidence interval (RMSEz * 1.96) = 10.10 cm

The number of checkpoints tested for LPC VVA : 164

The 95th percentile value for LPC VVA is : 22.48 cm

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.

Data covers the entire area specified for this project.

Data is backed up to tape and to cloud storage.