HGAC 1/2400 Digital Color Orthophotography (2006)

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Metadata:

Identification_Information:
Citation:
Citation_Information:
Originator: Kucera International Inc.
Publication_Date: Unknown
Title: HGAC 1/2400 Digital Color Orthophotography (2006)
Edition: 1.0
Geospatial_Data_Presentation_Form: Remote-sensing image
Publication_Information:
Publication_Place: Houston, Texas
Publisher: Houston-Galveston Area Council
Description:
Abstract:
This metadata record describes the 1/2400 scale 0.5' pixel natural color orthophotography produced in 2006 by Kucera International Inc. for H-GAC.
Purpose:
An orthophoto is a geometrically accurate photographic record of landscape conditions at the time of the corresponding aerial photography. As such, the orthophoto is useful for a variety of applications, such as environmental monitoring, facility engineering/maintenance, city/county planning, property line review, etc. It can be used alone or as a raster basemap for corresponding vector line mapping.
Supplemental_Information:
The bounding coordinates are for all imagery of this scale within the project area, not an individual image tile.
Time_Period_of_Content:
Time_Period_Information:
Multiple_Dates/Times:
Single_Date/Time:
Calendar_Date: 20060108
Single_Date/Time:
Calendar_Date: 20060111
Currentness_Reference: Ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: Unknown
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -095.755057
East_Bounding_Coordinate: -095.028255
North_Bounding_Coordinate: 30.038872
South_Bounding_Coordinate: 29.287172
Keywords:
Theme:
Theme_Keyword_Thesaurus: KI Thesaurus
Theme_Keyword: Aerial imagery
Theme_Keyword: Aerial photograph
Theme_Keyword: Basemap
Theme_Keyword: Digital orthophoto
Theme_Keyword: Othophoto
Place:
Place_Keyword_Thesaurus: GNIS
Place_Keyword: Brazoria County
Place_Keyword: Chambers County
Place_Keyword: Fort Bend County
Place_Keyword: Galveston County
Place_Keyword: Harris County
Place_Keyword: Liberty County
Place_Keyword: Montgomery County
Place_Keyword: Waller County
Access_Constraints: None
Use_Constraints: None
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Thomas Schultz
Contact_Organization: Houston-Galveston Area Council
Contact_Position: GIS Analyst & DBA Data Services
Contact_Address:
Address_Type: mailing and physical
Address: 3555 Timmons Lane, Suite 120
City: Houston
State_or_Province: TX
Postal_Code: 77027
Country: US
Contact_Voice_Telephone: 713-933-4568
Contact_Facsimile_Telephone: 713-993-2481
Contact_Electronic_Mail_Address: Thomas.Schultz@h-gac.com
Hours_of_Service: 0800-1700 CST, M-F
Data_Quality_Information:
Logical_Consistency_Report:
Compliance with the accuracy standard was ensured by the placement of GPS ground control prior to the acquisition of aerial imagery. The following checks were performed:
1. The airborne GPS/INS data stream was validated and solved in forward and reverse using Applanix's POSPAC software. The control and imagery were validated in the aerotriangulation bundle adjustment process using Inpho's MatchAT software.
2. Digital orthophotography was validated through a visual inspection of control points, edge matching and general image quality.
Completeness_Report:
The following methods were used to ensure image quality:
1. Use of targeted ground control during image acquisition.
2. Use of GPS/INS during image acquisition.
3. Checking of controls against ortho product.
4. Post ortho accuracy approval checks for overall image quality (tone, color balance, etc.).
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
This image complies with ASPRS Class II standards. It has been tested at 95% confidence level to have an RMS positional displacement within 4 feet of well defined ground features in obscured areas. Does not apply to vertical surface features, such as structures, appearing in the digital orthophotography due to inherent lean. Tested horizontal RMSE on controls within the project area is 1.04'. No individual point exceeded 2.2'.
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report: There is no vertical component for orthos.
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator: Kucera International Inc.
Publication_Date: Unpublished material
Title: Aerial photography
Edition: 1.0
Geospatial_Data_Presentation_Form: Remote-sensing image
Publication_Information:
Publication_Place: None
Publisher: None
Source_Scale_Denominator: 10800
Type_of_Source_Media: film
Source_Time_Period_of_Content:
Time_Period_Information:
Multiple_Dates/Times:
Single_Date/Time:
Calendar_Date: 20060108
Single_Date/Time:
Calendar_Date: 20060111
Source_Currentness_Reference: Ground condition
Source_Citation_Abbreviation: IMG
Source_Contribution:
Film based aerial images are scanned for use in AT, map compilation and ortho production.
Source_Information:
Source_Citation:
Citation_Information:
Originator: Geodetic Services
Publication_Date: Unpublished material
Title: Ground control
Edition: 1.0
Geospatial_Data_Presentation_Form: Vector digital data
Publication_Information:
Publication_Place: None
Publisher: None
Type_of_Source_Media: disc
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2006 Jan
Source_Currentness_Reference: Ground condition
Source_Citation_Abbreviation: CONT
Source_Contribution:
Targeted ground control is used to create a digital control file and control report as well as QC check of ortho accuracy. Predefined points (usually NGS) within the county are targeted, making the points visible in the photography. These points along with their precise coordinates are used in the AT process and to check the horizontal accuracy of the resulting orthophotos. 90 control points were targeted for use throughout the project area.
Source_Information:
Source_Citation:
Citation_Information:
Originator: Kucera International Inc.
Publication_Date: Unpublished material
Title: Digital elevation model
Edition: 1.0
Geospatial_Data_Presentation_Form: Vector digital data
Publication_Information:
Publication_Place: None
Publisher: None
Source_Scale_Denominator: 10800
Type_of_Source_Media: disc
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2006
Source_Currentness_Reference: Ground condition
Source_Citation_Abbreviation: DEM
Source_Contribution:
The DEM was comprised of LiDAR point data and new photogrammetrically compiled breaklines and spots from the 1/10800 aerial photography. The LiDAR data was supplied by client for areas in Fort Bend and Harris Counties. This was then gridded to 25' with the breaks imported to create the DEM for ortho production.
Source_Information:
Source_Citation:
Citation_Information:
Originator: HCAC
Publication_Date: Unknown
Title: Tile definition
Edition: 1.0
Geospatial_Data_Presentation_Form: Vector digital data
Publication_Information:
Publication_Place: Unknown
Publisher: Unknown
Type_of_Source_Media: disc
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2006
Source_Currentness_Reference: Ground condition
Source_Citation_Abbreviation: TLDEF
Source_Contribution:
The tile definition contains the name and bounding coordinates for each tile in the image index and is used to cut orthorectified imagery into manageable, usable images. Each tile is 6550 X 4300 feet. It was provided to Kucera by HGAC in vector format and references NAD83 SPCS Texas South-Central state plane coordinates. Kucera converted to an ASCII text file for use in image processing software.
Source_Information:
Source_Citation:
Citation_Information:
Originator: Kucera International Inc.
Publication_Date: Unpublished material
Title: Orthorectified imagery
Edition: 1.0
Geospatial_Data_Presentation_Form: Remote-sensing image
Publication_Information:
Publication_Place: None
Publisher: None
Source_Scale_Denominator: 2400
Type_of_Source_Media: disc
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2006
Source_Currentness_Reference: Ground condition
Source_Citation_Abbreviation: OIMG1
Source_Contribution:
This first level of orthorectified images results from using the AT solution and the DEM to create an orthophoto from each scanned exposure.
Source_Information:
Source_Citation:
Citation_Information:
Originator: Kucera International Inc.
Publication_Date: Unpublished material
Title: Tiled Orthophoto
Edition: 1.0
Geospatial_Data_Presentation_Form: Remote-sensing image
Publication_Information:
Publication_Place: None
Publisher: None
Source_Scale_Denominator: 2400
Type_of_Source_Media: disc, DVD or online
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2006
Source_Currentness_Reference: Ground condition
Source_Citation_Abbreviation: OIMG2
Source_Contribution:
The tiled orthophoto is the result of mosaicking orthorectified imagery and using the tile definition to cut into manageable, usable orthophotos.
Process_Step:
Process_Description:
At selected locations throughout the site, accurate GPS coordinates and elevations are surveyed and the points are marked with targets which will be visible in the aerial photography.
Source_Used_Citation_Abbreviation: None
Process_Date: 2006
Source_Produced_Citation_Abbreviation: CONT
Process_Step:
Process_Description:
New color aerial photography of the site is acquired using a USGS calibrated/approved aerial camera system mounted in a twin-engine aircraft. Film type used was AGFA Color X100. Camera information:

1. Zeiss RMK Top 15, serial no. 142832, focal length of 153.850mm, AWAR 101, last calibrated in June 2003.

During the aerial photography, the XYZ position of the camera center (principal point) and angular orientation of the aerial camera at the instant of each exposure is accurately measured using an airborne GPS/INS system interfaced with the aerial camera. GPS base-station receivers are operated on the ground over known site points during the flyover to provide data necessary to reference the aerial camera position and orientation measurements to the terrain coordinate system.
Source_Used_Citation_Abbreviation: None
Process_Date: 20060108 20060111
Source_Produced_Citation_Abbreviation: IMG
Process_Step:
Process_Description:
The aerial photography is processed, checked, titled, and scanned. Scanning was in direct negative form in a single pass on Z/I Imaging PhotoScan 2000 system. Scanning resolution used was 14 microns (1800dpi).
Source_Used_Citation_Abbreviation: IMG
Process_Date: 2006
Source_Produced_Citation_Abbreviation: IMG
Process_Step:
Process_Description:
The airborne GPS/IMU data is processed, in both forward and reverse directions, together with the simultaneously recorded ground-based GPS base station data to determine the aerial camera position and orientation in the terrain (project) coordinate datum during image collection.
Source_Used_Citation_Abbreviation: None
Process_Date: 2006
Source_Produced_Citation_Abbreviation: None
Process_Step:
Process_Description:
Using the processed GPS/INS data and correctly oriented imagery, a bundle adjustment is computed (AT) in Inpho's Match AT software.
Source_Used_Citation_Abbreviation: IMG, CONT
Process_Date: 2006
Source_Produced_Citation_Abbreviation: None
Process_Step:
Process_Description:
The scanned digital photo imagery for each exposure is directly oriented on digital orthophoto production stations using the AT bundle adjustment and rectified to digital elevation model data. Image rectification was performed using Inpho Orthomaster.
Source_Used_Citation_Abbreviation: IMG, DEM
Process_Date: 2006
Source_Produced_Citation_Abbreviation: OIMG1
Process_Step:
Process_Description:
Using automatic image processing software, blocks of rectified digital images are mosaicked together, radiometrically adjusted (tone balanced) across the images to achieve a generally seamless appearance, and cut into individual tiled images. The processing was completed using Stellacore Orthovista.
Source_Used_Citation_Abbreviation: OIMG1, TILEDEF
Process_Date: 2006
Source_Produced_Citation_Abbreviation: OIMG2
Process_Step:
Process_Description:
The individual final tiled images are subject to manual QC review, including feature representation, edge match, radiometry, and geometric accuracy. Positions of targeted ground points observable in the imagery are compared against their surveyed coordinate positions as a geometric accuracy check.
Source_Used_Citation_Abbreviation: OIMG2
Process_Date: 2006
Source_Produced_Citation_Abbreviation: OIMG2
Process_Step:
Process_Description:
Back-up copies of raw scanned and rectified imagery are maintained.
Source_Used_Citation_Abbreviation: OIMG2
Process_Date: 2006
Source_Produced_Citation_Abbreviation: OIMG2
Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:
Raster_Object_Type: Pixel
Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Grid_Coordinate_System:
Grid_Coordinate_System_Name: State Plane Coordinate System 1983
State_Plane_Coordinate_System:
SPCS_Zone_Identifier: 4204 Texas South-Central
Lambert_Conformal_Conic:
Standard_Parallel: 28.383333
Standard_Parallel: 30.283333
Longitude_of_Central_Meridian: -099.000000
Latitude_of_Projection_Origin: 27.833333
False_Easting: 1968499.999800
False_Northing: 13123333.332000
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: Coordinate pair
Coordinate_Representation:
Abscissa_Resolution: 0.5'
Ordinate_Resolution: 0.5'
Planar_Distance_Units: US Feet
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: Geodetic Reference System 80
Semi-major_Axis: 20925604.472041
Denominator_of_Flattening_Ratio: 298.25722210088
Vertical_Coordinate_System_Definition:
Altitude_System_Definition:
Altitude_Datum_Name: North American Vertical Datum of 1988
Altitude_Resolution: 0
Altitude_Distance_Units: US Feet
Altitude_Encoding_Method: Implicit coordinate
Entity_and_Attribute_Information:
Overview_Description:
Entity_and_Attribute_Overview:
Color orthophotos are comprised of pixels. Each pixel is assigned a value of 0 to 255. That number will refer to a color look-up table which contains red, green and blue (RGB) values, each from 0 to 255, for that pixel within the image.
Entity_and_Attribute_Detail_Citation: None
Distribution_Information:
Distributor:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Thomas Schultz
Contact_Organization: Houston-Galveston Area Council
Contact_Position: GIS Analyst & DBA – Data Services
Contact_Address:
Address_Type: mailing and physical
Address: 3555 Timmons Lane, Suite 120
City: Houston
State_or_Province: TX
Postal_Code: 77027
Country: US
Contact_Voice_Telephone: 713-933-4568
Contact_Facsimile_Telephone: 713-993-2481
Contact_Electronic_Mail_Address: Thomas.Schultz@h-gac.com
Hours_of_Service: 0800-1700 CST, M-F
Resource_Description: HCAC 1/2400 Digital Color Orthophotography (2006)
Distribution_Liability:
Houston-Galveston Area Council provides the geographic data "as is". This organization makes no guarantee or warranty concerning the accuracy of information contained in the geographic data. Also, this organization makes no warranty, either express or implied, regarding the condition of the product or its fitness for any particular purpose. The burden for determining fitness for use lies entirely with the user. Although these files have been processed successfully on computers at this organization, no warranty is made by this organization regarding the use of these data on any other system, nor does the fact of distribution constitute or imply such a warranty.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: SID
Transfer_Size: 19MB (appx.)
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name: <http://www.h-gac.com/HGAC/Programs/GIS/default.htm>
Access_Instructions: TBA
Offline_Option:
Offline_Media: CDROM, DVD, HD
Recording_Capacity:
Recording_Density: 0.7, 4.4, HD as supplied
Recording_Density_Units: GB
Recording_Format: Unknown
Fees: CD=$150, DVD=$350, External Drive=$1,250
Ordering_Instructions: Contact Thomas Schultz at H-GAC
Turnaround: 5 business days
Custom_Order_Process: Contact Thomas Schultz at H-GAC
Technical_Prerequisites: PC with CDROM or DVD drive
Available_Time_Period:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: Unknown
Metadata_Reference_Information:
Metadata_Date: 20061214
Metadata_Review_Date: 20071121

Metadata_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Thomas Schultz
Contact_Organization: Houston-Galveston Area Council
Contact_Position: GIS Analyst & DBA – Data Services
Contact_Address:
Address_Type: mailing and physical
Address: 3555 Timmons Lane, Suite 120
City: Houston
State_or_Province: TX
Postal_Code: 77027
Country: US
Contact_Voice_Telephone: 713-933-4568
Contact_Facsimile_Telephone: 713-993-2481
Contact_Electronic_Mail_Address: Thomas.Schultz@h-gac.com
Hours_of_Service: 0800-1700 CST, M-F
Metadata_Standard_Name: FGDC CSDGM
Metadata_Standard_Version: FGDC-STD-001-1998
Generated by mp version 2.9.1 on Wed Nov 21 09:34:44 2007