2004 Digital Orthophoto (Natural Color)

Metadata also available as

Metadata:

Identification_Information:
Citation:
Citation_Information:
Originator: St. Johns River Water Management District (SJRWMD)
Publication_Date: 2004
Title: 2004 Digital Orthophoto (Natural Color)
Geospatial_Data_Presentation_Form: SDE raster digital data
Publication_Information:
Publication_Place: Palatka, FL
Publisher: SJRWMD
Online_Linkage:
Server=earth; Service=esri_sde; Database=gislib; User=gislib; Version=SDE.DEFAULT
Description:
Abstract:
The following text is from the metadata for one of the original images:
This dataset is a single orthophoto from a collection of GeoTIFF format natural color orthophotos covering the St. Johns River Water Management District.
An orthophoto is remotely sensed image data in which displacement of features in the image caused by terrain relief and sensor orientation have been athematically removed. Orthophotography combines the image characteristics of a photograph with the geometric qualities of a map. Each orthophoto provides imagery for a nominal 3.75 minute (in latitude and longitude) cell area. The source imagery was obtained from December 2003 to March 2004 and used to produce orthophotos with a one meter ground resolution. Imagery was acquired at 0.62 meter ground sample distance (GSD) resolution. Flight height maintained during mission was 20,000 feet AGL. The imagery was captured at 12-bit radiometric resolution and converted to 8-bit radiometric resolution during post processing. The imagery was captured with 20% sidelap between all adjacent flight lines. The SJRWMD project area was divided into 5 flight blocks due to necessary base station and flight line length requirements. The imagery was obtained and processed by all digital means beginning with data acquisition using a Leica ADS40 Digital Airborne Sensor. The orthophotos are available in GeoTIFF form. The projected coordinate system is UTM zone 17 N, NAD 83 HARN, GRS 80, Units Meters.
Purpose:
The goal of this project is to update the St. Johns River Water Management District's digital orthophoto quarter quadrangle (DOQQ) database. The DOQQ database was originally created in 1994 and updated in 1999, and this project represents the iteration. The DOQQ database has become the standard basemap for the District's Geographic Information System (GIS) and is widely used throughout Florida. This dataset is part of a broader statewide DOQQ mapping effort.
Supplemental_Information:
USGS 7.5-minute DEMs were used to orthorectify the ADS40 imagery. Some quarterquads along the coast are primary water, with only a small percentage of land area and surface elevations. In these quarterquads the error and uncertainty in the DEM surfaces increase, and can affect rectification of the imagery in ocean water areas as the distance from land increases. The accuracy of DEM data depends on the source and resolution of the data samples. DEM data accuracy is derived by comparing linear interpolation elevations in the DEM with corresponding map location elevations and computing the statistical standard deviation or root-mean-square error (RMSE). The RMSE is used to describe the DEM accuracy. For 7.5-minute DEM's derived from a photogrammetric source, 90 percent have a vertical accuracy of 7-meter RMSE or better and 10 percent are in the 8- to 15-meter range. For 7.5- and 15-minute DEM's derived from vector or DLG hypsographic and hydrographic source data, an RMSE of one-half of a contour interval or better is required.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 2003/12/20
Ending_Date: 2004/3/20
Currentness_Reference: Date of source imagery acquisition.
Status:
Progress: In work
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -82.522307
East_Bounding_Coordinate: -80.289357
North_Bounding_Coordinate: 30.879253
South_Bounding_Coordinate: 27.429356
Keywords:
Theme:
Theme_Keyword_Thesaurus: SJRWMD-GIS Metadata Thesaurus
Theme_Keyword: ImageryBaseMapsEarthCover
Theme_Keyword: orthorectified
Theme_Keyword: orthophoto
Theme_Keyword: orthoimagery
Theme_Keyword: Infrared (IR)
Theme_Keyword: framework
Theme_Keyword: Digital
Theme_Keyword: DOQQ
Place:
Place_Keyword_Thesaurus: SJRWMD-GIS Metadata Thesaurus
Place_Keyword: Florida
Place_Keyword: St. Johns River Water Management District
Place_Keyword: Alachua County
Place_Keyword: Baker County
Place_Keyword: Bradford County
Place_Keyword: Brevard County
Place_Keyword: Clay County
Place_Keyword: Duval County
Place_Keyword: Flagler County
Place_Keyword: Indian River County
Place_Keyword: Lake County
Place_Keyword: Marion County
Place_Keyword: Nassau County
Place_Keyword: Okeechobee County
Place_Keyword: Orange County
Place_Keyword: Osceola County
Place_Keyword: Polk County
Place_Keyword: Putnam County
Place_Keyword: Seminole County
Place_Keyword: St. Johns County
Place_Keyword: Volusia County
Access_Constraints: none
Use_Constraints:
The St. Johns River Water Management District prepares and uses information for its own purposes and this information may not be suitable for other purposes. This information is provided "as is". Further documentation of this data can be btained by contacting: St. Johns River Water Management District, Division of Integrated Application Systems, Post Office Box 1429, Palatka, Florida, 2178-1429, (386) 329-4500.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: St. Johns River Water Management District
Contact_Person: GIS Data Manager, Information Resources Department
Contact_Address:
Address_Type: physical address
Address: St. Johns River Water Management District
Address: 4049 Reid Street
City: Palatka
State_or_Province: Florida
Postal_Code: 32177
Contact_Voice_Telephone: (386) 329-4500
Contact_Electronic_Mail_Address: gis_support@sjrwmd.com
Native_Data_Set_Environment:
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.2.5.1450
Cross_Reference:
Citation_Information:
Originator: St. Johns River Water Management District
Publication_Date: Unknown
Title: USGS Quarter Quad Index 1:12,000
Other_Citation_Details: Provides a spatial index for users to identify quarter quads.
Data_Quality_Information:
Logical_Consistency_Report:
Sample points taken from overlapping areas of adjacent image strips that contributed image chips to each orthophoto tile are typically consistent to the 2-3 pixel level. This not only ensures that a consistent mosaic can be created from the adjacent image strips acquired with the ADS40 pushbroom scanner but also means that the images have good precision and as a group are spatially self-consistent.
When these images were compared to the most recent USGS available one meter orthophoto images (1999) good agreement (typical deviations of 2-4 meters) were observed. These two sets of compared images were produced by different methods and positional differences between them does not indicate that one set of images is more accurate positionally than the other.
GeoTIFF headers are not standard USGS headers.
Completeness_Report:
These data cover the entirety of St. Johns River Water Management District. Each orthophoto has an overedge of approximately 30 meters on all sides of its centering 3.75 minute cell. Cells that are on the edge of the district are sometimes smaller than the typical nominal 3.75 minute tile size.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
Data specifications for the 2004 DOQQs stated that the horizontal accuracy should "... meet or exceed National Map Accuracy Standards (NMAS) for 1:12,000 maps as defined in National Mapping Program Technical Instructions, Standards for Digital Orthophotos, dated December 1996". Specifically NMAS stipulates that 90 percent of the well-defined points tested must fall within 33.3 feet (1/30 inch) at 1:12000 scale.
As reported by the contractor, 3001 Inc., the mean RMS error for 16 points designated "checkpoints" (points not incorporated into any adjustment iterations) was 1.7 meters (5.6 feet). An independent resample of 8 of these checkpoints by District staff (Division of Surveying) yielded a mean RMS error of 2.3 meters (7.5 feet). Both results are well within the threshold of 33.3 feet (~ 10 meters) stipulated by the contract. Additionally, District survey staff generated 16 independent checkpoints, with a mean RMS of 3.2 meters (10.5 feet), again well within the limits established.
The differences in measurement results obtained on re-sampled contractor control points can be attributed to the different measurement techniques employed, as well as the somewhat subjective nature of field determination of the measurement target.
It is important to note the following: 1. This assessment was not exhaustive, and did not endeavor to quantify the spatial accuracy of the data. Rather, this was a sampling of the data to assess compliance with a defined accuracy standard. 2. Not all areas of the project will have the same horizontal accuracy. Assessments specific to each individual DOQQ should be performed when the spatial project requires known accuracies. It is ultimately the responsibility of the end user to decide if the accuracy is acceptable for their project.
Lineage:
Process_Step:
Process_Description:
Ground control consisted of photo identifiable surveyed points. Beyond necessary production requirements an additional 30% GCPs were collected for quality control checks. The imagery was collected at an altitude of 6096m using an ADS40 digital sensor. Image quality was verified during the post flight review phase. Factors considered during this review included but were not limited to the presence of smoke and/or cloud cover, contrails, light conditions and sun glint.
The triangulated strips were rectified with a USGS DEM of the area. The vertical accuracy of the DEM varies based on the elevation postings and is generally estimated at 3-7m. The red, green and blue bands were combined to generate a final orthophoto.
The ADS40 sensor collects twelve bit image data which requires radiometric adjustment for output in standard eight bit image channels. Converting to eight bit results in a reduction of the color range from 4096 to 256 - thus loss of radiometric detail is inevitable. The extra dynamic range of the sensor permits greater object differentiation in shadows and in bright areas. The sixteen bit dynamic range permitted the imagery to be more effectively color balanced than is possible with eight bit imagery. This was accomplished by performing tonal enhancements immediately prior to the reduction from sixteen bit to eight bit data. In addition to color balancing these eight bit images were adjusted to create seamless imagery to the highest extent practically achievable.
The imagery was mosaicked using a combination of automated and manual seamlines generation. Project specified tiles were extracted from the mosaic. Final image tiles were reviewed for artifacts and anomalies and adjusted as part of quality control procedures. Adjacent images are compared for consistency in overlap regions. The images are reviewed for rectification problems such as bridge displacements caused by the underlying digital elevation model. When necessary, local corrections to the imagery were performed to minimize such effects.
Process_Date: 200401 - 200402
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: 3001, Inc.
Contact_Person: Matthew Bennett
Contact_Address:
Address_Type: mailing and physical address
Address: 3601 SW 2nd Avenue Suite Y
City: Gainesville
State_or_Province: FL
Postal_Code: 32607
Contact_Voice_Telephone: (352) 379-3001
Process_Step:
Process_Description:
sderaster -o import and sderaster -o mosaic command is used to mosaic tif images into sde
Process_Date: 8/20/3004
Process_Step:
Process_Description:
sderaster -o pyramid -L 18 sderaster -o stats
Process_Date: 8/21/2004
Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:
Raster_Object_Type: Pixel
Row_Count: 381367
Column_Count: 213463
Vertical_Count: 1
Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Map_Projection:
Map_Projection_Name: Transverse Mercator
Transverse_Mercator:
Scale_Factor_at_Central_Meridian: 0.999600
Longitude_of_Central_Meridian: -81.000000
Latitude_of_Projection_Origin: 0.000000
False_Easting: 500000.000000
False_Northing: 0.000000
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: row and column
Coordinate_Representation:
Abscissa_Resolution: 1.000000
Ordinate_Resolution: 1.000000
Planar_Distance_Units: meters
Geodetic_Model:
Horizontal_Datum_Name: D_North_American_1983_HARN
Ellipsoid_Name: Geodetic Reference System 80
Semi-major_Axis: 6378137.000000
Denominator_of_Flattening_Ratio: 298.257222
Vertical_Coordinate_System_Definition:
Altitude_System_Definition:
Altitude_Resolution: 1.000000
Altitude_Encoding_Method:
Explicit elevation coordinate included with horizontal coordinates
Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: St. Johns River Water Management District
Contact_Person: GIS Data Manager, Information Resources Department
Contact_Address:
Address_Type: Physical address
Address: St. Johns River Water Management District
Address: 4049 Reid Street
City: Palatka
State_or_Province: Florida
Postal_Code: 32177
Contact_Voice_Telephone: (386) 329-4500
Contact_Electronic_Mail_Address: gis_support@sjrwmd.com
Resource_Description: Downloadable Data
Distribution_Liability:
The St. Johns River Water Management District prepares and uses information for its own purposes and this information may not be suitable for other purposes. This information is provided "as is". Further documentation of this data can be obtained by contacting: St. Johns River Water Management District, Division of Integrated Application Systems, Post Office Box 1429, Palatka, Florida, 32178-1429, (386) 329-4500.
Standard_Order_Process:
Non-digital_Form: RGB DOQQ as JPEG2000 compressed /CD-ROM
Fees: $40 per CD
Ordering_Instructions:
There is no charge for downloading data from the District web site at <http://www.sjrwmd.com>. Data can be ordered on CD-ROM as instructed on the web site.
Turnaround: 10 working days
Custom_Order_Process:
1. Use the District website: <http://www.sjrwmd.com> to download data, or 2. Call or email to organizations listed under Distributor.
Technical_Prerequisites:
Internet access / Unzip, Winzip / To use image: ESRI ArcInfo, ArcGIS 8.3, or ArcExplorer; AutoCAD 2002 Map or Land Development Desktop.
Metadata_Reference_Information:
Metadata_Date: 20080811
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: SJRWMD
Contact_Person: Chris Mundy
Contact_Address:
Address_Type: mailing address
Address: 4049 Reid Street
City: Palatak
State_or_Province: FL
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
Metadata_Extensions:
Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>
Profile_Name: ESRI Metadata Profile
Metadata_Extensions:
Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>
Profile_Name: ESRI Metadata Profile
Generated by mp version 2.9.6 on Fri Feb 13 10:57:55 2009