2004 ENSR Bare Earth Topographic Lidar: Hampden County, Massachusetts
This kmz file shows the extent of coverage for the 2004 ENSR Hampden County, MA lidar
Spectrum Mapping was tasked by ENSR International (now a subsidiary of AECOM Technology
Corporation) to collect LIDAR data and digital ortho imagery to generate breaklines
and a bare earth DEM to support 2-foot contour intervals in accordance with FEMA Appendix
A. The project area for Connecticut River floodplain was approximately 143 square
miles in Hampden County, Massachusetts. The Spectrum aircraft was equipped with the
RAMS system, including a 26 Khz Laser, an inertial measurement unit (IMU), and a dual
frequency GPS receiver and antenna. The RAMS sensor system also includes a RAMS 4K
X 4K color digital camera mounted to the LIDAR unit.
Cite this dataset when used as a source.
|Search and Download
|| Distributor information not available
| Point of Contact
- ENSR International Corporation
|Data Presentation Form:
|| Digital image
|Dataset Progress Status
|Data Update Frequency:
|| As needed
||The purpose of this project was to collect LIDAR data and digital ortho imagery to
generate breaklines and a bare earth DEM to support 2-foot contour intervals in ccordance
with FEMA Appendix A.
||2004-05-13 to 2004-06-03
|Spatial Reference System:
|Spatial Bounding Box Coordinates:
|Spatial Coverage Map:
- Bare Earth
- Remote Sensing
- Hampden County
- Connecticut River
| Use Constraints
|| No constraint information available
|| Fee information not available.
|| Lineage statement not available.
| Processing Steps
- Detailed information about Spectum Mapping's data processing procedures can be found
in the Project Report located above in the Supplemental_Information section.
- The NOAA Coastal Services Center (CSC) received topographic files in ASCII .CSV format.
The files contained bare earth lidar elevation measurements in X,Y,Z format. The data
were received in Massachusetts State Plane Mainland Zone 2001, NAD83 coordinates and
were vertically referenced to NAVD88 using the Geoid99 model. The vertical units of
the data were feet. CSC performed the following processing for data storage and Digital
Coast provisioning purposes: 1. The topographic las files were converted from ASCII
to LAS format. 2. The classification of all bare earth points was changed from Class
0 to Class 2. 3. The topographic las files were converted from orthometric (NAVD88)
heights to ellipsoidal heights using Geoid99. 4. The topographic las files were converted
from a Projected Coordinate System (MA SP Mainland) to a Geographic Coordinate System
(NAD83). 5. The topographic las files' vertical units were converted from feet to
meters. 6. The topographic las files' horizontal units were converted from feet to
decimal degrees. 7. The data were converted to LAZ format.
- The NOAA National Geophysical Data Center (NGDC) received lidar data files via ftp
transfer from the NOAA Coastal Services Center. The data are currently
being served via NOAA CSC Digital Coast at http://www.csc.noaa.gov/digitalcoast/.
The data can be used to re-populate the system. The data are archived in LAS or LAZ
The LAS format is an industry standard for LiDAR data developed by the American Society
of Photogrammetry and Remote Sensing (ASPRS); LAZ is a loseless compressed version
LAS developed by Martin Isenburg (http://www.laszip.org/). The data are exclusively
in geographic coordinates (either NAD83 or ITRF94). The data are referenced vertically
the ellipsoid (either GRS80 or ITRF94), allowing for the ability to apply the most
up to date geoid model when transforming to orthometric heights.
Metadata Last Modified: 2013-11-26
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