This metadata record describes the acquisition and production of Building Footprints for 5 coastal counties Hancock, Harrison, Jackson, Pearl River and Stone. The buildings were collected from digital imagery with a 15 and 30 cm ground sample distance (GSD) for the project area. All imagery was acquired in spring 2007 and processed during the spring & summer of 2007. The imagery is from a project tasked by Mississippi Geographic Information, LLC (MGI) with Work Orders ED-9 & ED-9A. EarthData International, Inc. was authorized to undertake this project in accordance with the terms and conditions of the professional service agreement between MGI and EarthData International, Inc., dated February 14, 2007.
The acquisition of the Building Footprints and Points were completed as part of the Gulf Region Base Mapping Ownership Data Development Project under a contract to Mississippi Department of Environmental Quality. This project was funded through the Community Development Block Grant (CDBG) program for the reconstruction effort in the five coastal counties. The Building Footprints and Points collection was designed as a resource to aid the the State and local governments. This data will be posted on the Mississippi Geospatial Clearinghouse Portal as a Mississippi Digital Earth Model (MDEM) GIS layer.
PO Box 2279
This data has been produced to be fully compliant with the National Standard for Spatial Data Accuracy (NSSDA) at a scale fof 1"=100' and 1"=200'.
Compliance with the accuracy standard was ensured by the collection of photo identifiable GPS ground control after the acquisition of aerial imagery. The following checks were performed. 1. The ground control and airborne GPS data stream were validated through a fully analytical bundle aerotriangulation adjustment. The RMSE is less than 1/ 10,000th of the flying height. 2. The DSM (DEM) data was checked against the project control. The technician visited and confirmed the accuracy of the points during initial processing 3. Continuity was verified for the existing ground control within the project are on the stereo models.
The following methods are used to assure imagery accuracy. 1. Use of IMU (inertial measurment unit) and ground control network utilizing GPS techniques. 2. Use of airborne GPS (global positioning system) in conjunction with the acquisition of imagery. The following software is used for validation of the imagery and surface modeling. 1. Aerotriangulation - ISTAR 2. Bentley - MicroStation 3. ISTAR 4. ESRI - ArcView, ArcMap 5. EarthData proprietary software
This data has been produced to be fully compliant with the National Standard for Spatial Data Accuracy (NSSDA) for 1"=100' and 1"=200'.
The aerial imagery acquisition for MDEQ/MGI MS Coastal Counties was flown to support the creation of ground ortho digital photography with a 15cm GSD. The imagery was acquired in 10 lifts consisting of 128 flightlines at a height of 4782' AMT. Sidelap between flightlines is 30%. All imagery was collected using the Leica ADS40 digital pushbroom sensor.
Waggoner Engineering, Inc. was contracted by MGI & EarthData International, Inc. to acquire 58 vertical/horizontal photo-identifiable points. The ground control points were established using GPS for vertical and horizontal coordinate values. Horizontal datum is MS State Plane East NAD83/HARN, vertical is NAVD 88 both in US Survey feet.
EarthData utilized an ISTAR workflow for processing the aerotriangulation (AT) for the orthoimagery covering the MS Coastal Counties project areas. The airborne GPS data was processed and integrated with the inertial measurement unit (IMU). The resulting imagery and control were imported into the ISTAR system for use in the aerotriangulation. The ADS40 imagery was downloaded onto the EarthData server and brought over to the UNIX based ISTAR system. The ground control was used in conjunction with the processed airborne global positioning system (ABGPS) results for the AT. The ground control points were read in all available imagery and tie points between flight lines were selected. A fully analytical bundle adjustment was run. The properly formatted ISTAR results were used for subsequent processing. All final results were output into an AT report.
Utilizing the existing imagery from the previous Mississippi orthophotography project Fugro EarthData, Inc collected building outlines for existing permentent structures and FEMA trailers. All features were collected using Black and White stereoscopic imagery on softcopy photogrammetric workstations. The map scale was 1"= 100' and 1"=200'.
Internal feature number.
Length of feature in internal units.
Area of feature in internal units squared.
143-A LeFleurs Square
7320 Executive Way