Bare-Earth DEM

Identification_Information:

Citation:

Citation_Information:

Originator: Bohannan Huston, Inc.
Publication_Date: 20150410
Title: Bare-Earth DEM
Geospatial_Data_Presentation_Form: raster digital data
Series_Information:

Series_Name: Santa Fe County 2014 Regional LiDAR Project
Issue_Identification: Bare-Earth DEM (SFCO/USGS)

Publication_Information:

Publication_Place:

102 Grant Avenue Santa Fe, NM 87501

Publisher: Santa Fe County

Other_Citation_Details:

This dataset was created as a joint effort between Santa Fe County, the US Geological Survey, Bohannan Huston, Inc. and Aero-Graphics, Inc. in support of Santa Fe County Geographic Information Systems' mission.

Online_Linkage: http://www.santafecountynm.gov/growth_management/gis

Description:

Abstract:

Between March 12 and August 11, 2014, light detection and ranging (LiDAR) data was acquired over the entirety of Santa Fe County (SFCO) in New Mexico, as well as portions of Rio Arriba, Taos, Mora, Los Alamos, San Miguel, Torrance, Sandoval and Bernalillo Counties. The project area covers approximately 3,000 square miles of urban, desert, and mountain areas. The LiDAR data were acquired to meet a US Geological Survey (USGS) Quality Level 2 (QL2) standard. This bare earth Digital Elevation Model (DEM) dataset was developed from the classified LiDAR point cloud in combination with breakline data over select areas including significant walls, bridges and water bodies. It describes the ground surface within the project area. Published at 1:600 (1in=50ft) mapping scale, these DEM data are designed to support a 1 ft contour interval. Two identical series of these DEM data were created according to the two project tiling schemes—SFCO (Public Land Survey System (PLSS) section-based overlapping tiles) and USGS (non-overlapping, edge-matched 5000’x5000’ tiles). DEM datasets for the Santa Fe County series cover 3256 individual data tiles established for data processing and deliverable purposes.

Purpose:

The purpose of this project is to support activities throughout Santa Fe County, including but not limited to urban, community and regional planning; project and infrastructure planning; project reporting; floodplain mapping; stormwater management; vegetation analysis; change detection; and initial project reviews.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 20140312
Ending_Date: 20140811

Currentness_Reference: ground condition

Status:

Progress: Complete
Maintenance_and_Update_Frequency: As needed

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: 106°15’29.337364”W
East_Bounding_Coordinate: 105°36’38.644749”W
North_Bounding_Coordinate: 36°15’13.244489”N
South_Bounding_Coordinate: 34°59’26.579322”N

Keywords:

Theme:

Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: elevation

Place:

Place_Keyword_Thesaurus: http://www.getty.edu/research/tools/vocabularies/tgn/
Place_Keyword: Santa Fe County
Place_Keyword: Rio Arriba County
Place_Keyword: Taos County
Place_Keyword: Mora County
Place_Keyword: Los Alamos County
Place_Keyword: San Miguel County
Place_Keyword: Torrance County
Place_Keyword: Sandoval County
Place_Keyword: Bernalillo County
Place_Keyword: New Mexico
Place_Keyword: United States of America

Access_Constraints: None
Use_Constraints:

Neither Santa Fe County, nor Bohannan Huston, Inc. (BHI) assumes liability for misuse of the data. Data should be used at the scale for which they were intended. No warranty, expressed, or implied, is made by Santa Fe County nor BHI regarding the utility of the data on any other system, nor shall the act of distribution constitute such warranty.

Point_of_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Santa Fe County
Contact_Person: Erle Wright, GISP

Contact_Position: Data Integration Administrator
Contact_Address:

Address_Type: mailing address
Address: 102 Grant Avenue
City: Santa Fe
State_or_Province: New Mexico
Postal_Code: 87501
Country: USA

Contact_Voice_Telephone: 505-986-6350
Contact_Electronic_Mail_Address: ewright@santafecountynm.gov

Browse_Graphic:

Browse_Graphic_File_Name: sfco2014_dem.pdf
Browse_Graphic_File_Description:

View of 32-bit DEM data in elevation color shaded relief visualization with USGS tile scheme overlay.

Browse_Graphic_File_Type: portable document format

Data_Set_Credit:

Acknowledgement of Santa Fe County GIS, the U.S. Geological Survey, Bohannan Huston, Inc. and Aero-Graphics, Inc. would be appreciated for products derived from these data.

Native_Data_Set_Environment:

Intergraph GeoMedia Professional Ver. 14.00.0002.00088; Intergraph ERDAS IMAGINE 2014 Ver. 14.00.0100 Build 715; FME Desktop 2015.0 (Build 15244); Window 7 Enterprise SP1; tif files total ~84 GB

Data_Quality_Information:

Attribute_Accuracy:

Attribute_Accuracy_Report:

DEM data were processed to meet a 1 ft contour interval data vertical accuracy at the 95% confidence level (RMSE of 0.33 ft) in compliance with absolute vertical accuracy specifications for Quality Level 2 (QL2) DEM data. Ninety-five percent of well-defined features are expected to be within 0.64 ft of their true vertical position on the ground.

Logical_Consistency_Report:

DEM features in this data set were collected from a variety of active and passive remote sensing technologies including LiDAR (Light Detection and Ranging) and large scale aerial photography for orthophoto rectification and feature interpretation of ground and non-ground surface data.

Completeness_Report:

Deliverable data tiles were inspected to ensure complete terrain data coverage to the extent possible with overlapping LiDAR strip data within individual tiles. Therefore data tiles may be comprised of multiple flight line data sources including classified LiDAR point data. Sources covering the site are defined by flight line index information.

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report: Tested 1.5 ft horizontal accuracy (NSSDA).
Quantitative_Horizontal_Positional_Accuracy_Assessment:

Horizontal_Positional_Accuracy_Value: 1.5
Horizontal_Positional_Accuracy_Explanation:

LiDAR point cloud data were tested horizontally with 65 paneled or otherwise visible ground control points. Comparison of the horizontal ground control coordinates to the corresponding control point locations on LiDAR intensity imagery (with 2 ft GSD) were measured at the visible center of each control point panel to form the basis of the horizontal test. Reported accuracies developed from the sample of 65 control points exhibit a horizontal RMSE of 0.9 ft or 0.27 m.

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:

Tested 0.28 ft (8.4 cm) vertical accuracy (RMZEz, nonvegetated), 0.54 ft (16.6 cm) NSSDA NVA at 95-percent confidence level, and 0.38 ft (11.5 cm) VVA at 95th percentile.

Quantitative_Vertical_Positional_Accuracy_Assessment:

Vertical_Positional_Accuracy_Value: 0.28
Vertical_Positional_Accuracy_Explanation:

DEM data were tested with 41 independent check points utilizing points surveyed through OPUS projects and well-distributed across the entire project area. The DEM test elevation values were queried at the corresponding horizontal (x,y) pixel location of the check point. Land cover reporting groups were determined according to the National Land Cover Database (NLCD). These test DEM elevation values were compared to the independent z elevation values for the check point with corresponding results compiled into the Federal Geographic Data Committee (FGDC) National Standard for Spatial Data Accuracy (NSSDA) vertical accuracy assessment template spreadsheet.

Lineage:

Source_Information:

Source_Citation:

Citation_Information:

Originator: Bohannan Huston, Inc.; Alan R. Benham, P.S.
Publication_Date: 20141027
Title: Survey Control Report for SANTA FE COUNTY

Source_Scale_Denominator: 240
Type_of_Source_Media: Portable Document Format
Source_Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 20141027

Source_Currentness_Reference: ground condition

Source_Citation_Abbreviation: 20140344 Santa Fe Control Report REVISED 10-27-2014 SIGNED.pdf
Source_Contribution:

Geodetic control was established for the project to provide a primary control network for LIDAR and orthophotography mapping in the project coordinate system.

Source_Information:

Source_Citation:

Citation_Information:

Originator: Aero-Graphics Inc.
Publication_Date: 20140924
Title:

Airborne LiDAR Collection - Optech Orion H300 laser scanner with Inertial Measurement Unit (IMU) and on-board Global Positioning System (GPS).

Geospatial_Data_Presentation_Form: LiDAR Point Cloud

Source_Scale_Denominator: 600
Type_of_Source_Media: Hard drive
Source_Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 20140312
Ending_Date: 20140811

Source_Currentness_Reference: ground condition

Source_Citation_Abbreviation: SFCO2014_LiDAR_SWATH.shp
Source_Contribution:

LIDAR data was captured using an Optech ALTM Orion H300 LiDAR system with an inertial measurement unit (IMU) and dual frequency GPS receiver. Project acquisition with LiDAR sensors was organized into 5 acquisition blocks or "quadrants." Quadrants 1 and 5 predominantly covered the more mountainous areas of the project with more significant relief. Quadrants 2, 3, and 4 were acquired over the primarily flatter desert areas. Data acquisition across the project was designed to achieve a 0.7 m nominal pulse spacing (NPS).

Source_Information:

Source_Citation:

Citation_Information:

Originator: Aero-Graphics Inc.
Publication_Date: 20140924
Title:

Airborne Collection - Microsoft/Vexcel UltraCam Eagle (UCE) digital camera system with Inertial Measurement Unit (IMU) and on-board Global Positioning System (GPS).

Geospatial_Data_Presentation_Form: Image

Source_Scale_Denominator: 1200
Type_of_Source_Media: Hard drive
Source_Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 20140310
Ending_Date: 20140620

Source_Currentness_Reference: ground condition

Source_Citation_Abbreviation: SFCO2014_PHOTO_FOOTPRINTS.shp
Source_Contribution:

Digital aerial imagery was collected at a nominal average altitude of 9,466 ft above ground level (AGL) using the Microsoft/Vexcel UltraCam Eagle (UCE) digital camera system. The UCE aerial imagery served the purpose of supporting the production of 6 inch ground sample distance (GSD) resolution digital orthoimagery for interpretive value in evaluation and development of LiDAR-elevation products.

Source_Information:

Source_Citation:

Citation_Information:

Originator: USDA Aerial Photography Field Office (APFO)
Publication_Date: 20150313
Title: National Agriculture Imagery Program (NAIP) Imagery
Geospatial_Data_Presentation_Form: Image
Online_Linkage:

http://gis.apfo.usda.gov/arcgis/services/NAIP/New_Mexico_2014_1m/ImageServer/WMSServer?

Source_Scale_Denominator: 12000
Type_of_Source_Media: online
Source_Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 2014

Source_Currentness_Reference: ground condition

Source_Citation_Abbreviation: New_Mexico_2014_1m_NC
Source_Contribution:

For project areas outside of the UCE aerial imagery coverage, 2014 NAIP imagery with a 1 m GSD resolution was used to support interpretive value in evaluation and development of LiDAR-elevation products. In particular over these NAIP areas, imagery supported the definition of 2D polygons utilized in waterbody hydro flattening and point classification.

Process_Step:

Process_Description:

1. Triangulation. Using classified point cloud source data as an input, digital elevation models (DEM) were triangulated with FME® software. Classes 2 (ground) and 9 (water) where applicable were triangulated with a tolerance setting of 0.0 (i.e. no approximation). Class 10 (Ignored ground (near a breakline)) points were excluded from triangulation which results in creating a buffer between the LiDAR and the breakline for a smooth transition in the resulting DEM modeling at breakline locations.

Source_Used_Citation_Abbreviation: SFCO2014_LiDAR_SWATH.shp
Process_Date: 20150410

Process_Step:

Process_Description:

2. Non-river water body flattening. Ponds and lakes greater than 2 acres in size were processed during the DEM processing workflow through the use of breakline (polygons) data defining the extent of these water body features at the water/land interface. These breakline data were acquired from photogrammetric sources (project orthophotography and NAIP orthophotography) acquired over the project in 2014. After polygon delineation, the breaklines were fit to the appropriate LiDAR elevation at or below the water surface. A point cloud at this defined elevation was inserted into the DEM triangulation (surface modeling) process using the polygon features for flattening of the water body at the appropriate level.

Source_Used_Citation_Abbreviation: SFCO2014_PHOTO_FOOTPRINTS.shp
Source_Used_Citation_Abbreviation: New_Mexico_2014_1m_NC
Process_Date: 20150410

Process_Step:

Process_Description:

3. Breakline integration. Breakline features were analyzed and tracked according to their utility in supporting DEM surface modeling. Breakline features contributing to the modeling were marked with a “usage” attribute indicating weather of not the feature should be incorporated into the surface model. Processing filtered for breakline data where usage was equal to “yes.” For bridge features, these breaklines were clipped by a bridge deck polygon feature and therefore, the breakline data at bridge locations supplements surface modeling primarily under the deck. Breaklines were also combined into the surface modeling process at wall locations and culvert spans. End line segments where bridge decks touch the road were also processed into breakline features through feature manipulation of the bridge deck polygon. Here, the bridge deck polygon is chopped by two vertices segments and through spatial analysis to automatically extract the bridge abutment at the road elevation as a breakline.

Source_Used_Citation_Abbreviation: SFCO2014_PHOTO_FOOTPRINTS.shp
Source_Used_Citation_Abbreviation: New_Mexico_2014_1m_NC
Process_Date: 20150410

Process_Step:

Process_Description:

4. DEM Output. Triangulation processing was performed to generate two (2) sets of DEM output deliverable data tiles. One tiling scheme, designated “SFCO,” is organized according to the Public Land Survey System (PLSS) section-based overlapping tiles. The other tiling scheme, designated “USGS,” is composed of non-overlapping, edge-matched 5000’x5000’ gridded tiles. Both tiling schemes adhere to the same horizontal and vertical coordinate system, pixel resolution and source data inputs. In addition, both the SFCO and USGS tiling schemes are rounded to nearest ten (10) coordinate value units (U.S. Survey Feet) and both fall on even foot coordinates. Each tile is also divisible by two—the resolution of the DEM raster grid output. For processing purposes, in both cases a 999 ft over edge or buffer was used for triangulation and then clipped back to the tile definition upon output. This process helps ensure uniformly consistent and coincident data when modeling point cloud inputs to 2 ft grid pixels at tile edges where clipping occurs.

Source_Used_Citation_Abbreviation: SFCO2014_PHOTO_FOOTPRINTS.shp
Source_Used_Citation_Abbreviation: New_Mexico_2014_1m_NC
Source_Used_Citation_Abbreviation: SFCO2014_LiDAR_SWATH.shp
Process_Date: 20150410

Process_Step:

Process_Description:

5. Edge analysis. For partial data tiles (i.e. those tiles at the edge of the project boundary), special edge data handling procedures were implemented to meet two objectives. Steps were applied to ensure that data tiles conformed to the appropriate tile dimensions and that spurious data values were removed near data voids occurring near the edge. To accomplish these objectives, an artificial no data raster (with a fill value of -32767) and a zero (0) elevation las point cloud were generated to fill the no data portions of the tile. For edge data clipping, the strip geometry spatial metadata defining the spatial extents of the LiDAR coverage was used as a clipper to clip the zero elevation data which was inserted into the triangulation. To produce a full raster data tile, the zero (0) values were replaced with no-data values (-32767) by way of the clipper. In some areas, due to the spatial resolution of the metadata clipper, clipper boundaries were refined iteratively to further eliminate additional falsely triangulated DEM values.

Source_Used_Citation_Abbreviation: SFCO2014_LiDAR_SWATH.shp
Process_Date: 20150410

Process_Step:

Process_Description:

6. DEM Quality Control (QC). Review processes were developed to comprehensively assess output data tiles. This process is designed to detect and identify any areas, if any which may be systematically incomplete or contain inconsistent data. During this assessment, full project mosaics of all DEM tiles in each of the respective tiling schemes were computed. Next, vertical difference analysis across the full project mosaics for each DEM product supplied change detection areas for targeting where the data may not agree. This analysis would lead to reprocessing specific data (tiles) with subsequent QC analysis iterations performed to inspect for deviations from expected values. These mosaic-based QC processes also queried for tile count verification and/or processing omissions.

Process_Date: 20150410

Bare-Earth DEM

Metadata: