Maryland Digital Orthophoto Quarter Quadrangles

Metadata:

Identification_Information:
Citation:
Citation_Information:
Originator: Maryland Department of Natural Resources
Publication_Date: 19990706
Title: Maryland Digital Orthophoto Quarter Quadrangles
Geospatial_Data_Presentation_Form: Remote-Sensing Image
Series_Information:
Series_Name: Maryland Digital Orthophoto Quarter Quadrangles
Issue_Identification: see Supplemental Information Section
Publication_Information:
Publication_Place: Annapolis, Maryland
Publisher: Maryland Department of Natural Resources
Description:
Abstract:
Orthophotos combine the image characteristics of a photograph with the geometric qualities of a map. The color infrared (CIR) digital orthophotoquad (DOQ) is a 1-meter ground resolution, quarter-quadrangle (3.75-minutes of latitude by 3.75-minutes of longitude) image cast on the Universal Transverse Mercater Projection (UTM) on the North Americam Datum of 1983 (NAD83). The extent of the DOQ is equivalent to a quarter-quad plus the overedge which ranges from a minimum of 50 meters to a maximum of 300 meters beyond the extremeties of the primary and secondary corner points. The overedge is included to facilitate tonal matching for mosaicking and for the positioning of the NAD83 and secondary datum corner ticks. The normal orientation of data is by lines (rows) and samples (columns). Each line contains a series of pixels ordered from west to east wih the order of lines fom north to south. The digital orthophoto is formatted as an ASCII header record, followed by three 8-bit binary image data records representing the three color infrared bands. The radiometric image brightness values are stored as 256 gray levels ranging from 0 to 255.
Purpose:
DOQ's serve a variety of purposes, from interim maps to field references for earth science investigations and analysis. The DOQ is useful as a layer of a geographic information system (GIS) and as a tool for revision of digital line graphs and topographic maps.
Supplemental_Information:
This document covers the following DOQQ's : Rising Sun SE SW, Bay View SE SW, Newark West SW, Havre de Grace NE NW SE SW, North East NE NW SE SW, Elkton NW SW, Spesutie NE NW SE SW, Earlville NE NW SE SW, Cecilton NW SW, Betterton NE NW SE SW, Galena NE NW SW, Millington NW, Goldsboro SE, Ridgley SE, Denton NE NW SE SW, Easton NE NW SE SW, Fowling Creek NE NW SE SW, Hobbs NE NW SE SW, Trappe NE NW SE SW, Preston NE NW SE SW, Federalsburg NE NW SE SW, Cambridge NE NW SE SW, East New Market NE NW SE SW, Rhodesdale NE NW, Blackwater River NE NW SE SW, Chicamacomico NE NW SE SW, Wingate NE NW SE SW,and Nanticoke NW SW.
Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 19950325
Currentness_Reference: Ground Condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: Irregular
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -76.125
East_Bounding_Coordinate: -76
North_Bounding_Coordinate: 39
South_Bounding_Coordinate: 38.875
Keywords:
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: 3.75 x 3.75 minute orthophoto
Theme_Keyword: DOQQ
Theme_Keyword: Digital Orthophoto Quarter Quad
Theme_Keyword: DOQ
Theme_Keyword: Orthophoto
Theme_Keyword: Quarter Quadrangle Photo
Theme_Keyword: 1 - meter Orthophoto
Theme_Keyword: Aerial Photograph
Theme_Keyword: Digital Image Map
Theme_Keyword: Rectified Photograph
Theme_Keyword: Rectified Image
Place:
Place_Keyword_Thesaurus: None
Place_Keyword: Caroline County
Place_Keyword: Cecil County
Place_Keyword: Kent County
Place_Keyword: Maryland
Place_Keyword: USA
Place_Keyword: Talbot County
Place_Keyword: Dorchester County
Access_Constraints: None
Use_Constraints:
None. Acknowledgement of the Maryland Department of Natural Resources and the U.S. Geological Survey would be appreciated in products derived from these data.
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Kenneth M. Miller
Contact_Organization: Maryland Department of Natural Resources
Contact_Position:
Chief, Spatial Data Production Services, GIS Division
Contact_Address:
Address_Type: Mailing and Physical Address
Address: 580 Taylor Avenue
Address: Tawes State Office Building E-2
City: Annapolis
State_or_Province: Maryland
Postal_Code: 21401-
Country: USA
Contact_Voice_Telephone: (410) 260-8751
Contact_TDD/TTY_Telephone: (410) 260-8835
Contact_Facsimile_Telephone: (410) 260-8759
Contact_Electronic_Mail_Address: kenmiller@dnr.state.md.us
Hours_of_Service: 8:00 a.m. to 5:00 p.m. Monday - Friday
Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
During photographic reproduction of the source photography, limited analog dodging is performed to improve image quality. Analog dodging consists of holding back light from certain areas of the sensitized photographic material to avoid overexposure. The diapositive is inspected to insure clarity and radiometric uniformity. Diapositive image brightness values are collected with a minimum of image quality manipulation. Image brightness values may deviate from brightness values of the original imagery due to image value interpolation during the scanning and rectification processes. Radiometry is verified by visual inspection of the digital orthophoto quadrangle with the original unrectified image to determine if the digital orthophoto has the same or better image quality as the original unrectified input image. Slight systematic radiometric differences can be detected between adjacent DOQ files due primarily to differences in source photography capture dates and sun angles of aerial photography along flight lines. These differences can be observed in an image's general lightness or darkness when compared to adjacent DOQ file coverages.
Logical_Consistency_Report:
The data file has been imported into MicroImages TNTmips software (version 5.8). The image values and georeferencing data contained therein found to be complete and accurate.
Completeness_Report:
All DOQ imagery is visually inspected for completeness to ensure that no gaps, or image misplacement exist in the 3.75' image area or in overedge coverage. DOQ images may be derived by mosaicking multiple images, in order to insure complete coverage. All DOQ's are cloud free within the 3.75' image area. Source photography is leaf-off. Void areas having a radiometric value of zero and appearing black may exist. These are areas for which no photographic source is available or result from image transformation from other planimetric systems to the Universal Transverse Mercator (UTM). In the latter case, the void sliver areas are on the outside edges of the overedge area.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
The DOQ horizontal positional accuracy and the assurance of that accuracy depend, in part, on the accuracy of the data inputs to the rectification process. These inputs consist of the digital elevation model (DEM),aerotriangulation control and methods, the photo source camera calibration, scanner calibration, and aerial photographs that meet National Aerial Photography Program (NAPP) standards. The vertical accuracy of the verified USGS format DEM is equivalent to or better than a USGS level 1 or 2 DEM, with a root mean square error (RMSE) of no greater than 7.0 meters. Field control is acquired by third order class 1 or better survey methods sufficiently spaced to meet National Map Accuracy Staandards (NMAS) for 1:12,000-scale products. Aerial cameras have current certification from the USGS, National Mapping Division, Optical Science Laboratory. Test calibration scans are performed on all source photography scanners.
Lineage:
Process_Step:
Process_Description:
The production procedures, instrumentation, hardware and software described here are specific to the production of the DOQ's referenced in this document. The rectification process requires, as input, a user parameter file to control the rectification process, a digital elevation model (DEM) gridded to user specified bounds, projection, zone, datum and X-Y units, a scanned digital image file (PHOTO) covering the same area as the DEM, ground X-Y-Z point values (CONTROL) and their conjugate photo coordinates in the camera coordinate system, and measurements of the fiducial marks (CAMERA) in the digitized image. The camera calibration report (CAMERA) provides the focal length of the camera and the distances in millimeters from the camera's optical center to the camera's 8 fiducial marks. These marks define the frame of reference for spatial measurements made from the photograph. Ground control points (CONTROL) acquired from aerial GPS and developed in aerotriangulation, are third order class 1 or better, and meet National Map Accuracy Standard (NMAS) for 1:12,000-scale. Ground control points are in the Universal Transverse Mercator NAD83. Horizontal and vertical residuals of aerotriangulated tie-points are equal or less than 2.5 meters. Standard aerotriangulation passpoint configuration consists of 9 ground control points, one near each corner, one at the center near each side and 1 near the center of the photograph, are used. The conjugate positions of the ground control points on the photograph are measured and recorded in camera coordinates. The raster image file (PHOTO) is created by scanning an aerial photograph film diapositive with a precision image scanner (ZEISS scanner). An aperture of 25 microns is used. Using 1:40,000-scale photographs, a 25-micron scan aperture equates to a ground resolution of 1-meter. The scanner converts the photographic image densities to gray scale values ranging from 0 to 255 for black and white photographs. The elevation data source (DEM) is derived from the photography (PHOTO) using first order analytical stereo plotter instruments. All DEM data is equivalent to or better than USGS DEM standard level 1. The DEM used in the production of DOQ's has elevations derived on a 90-meter grid and interpolated on a 30-meter grid post spacing and possesses a vertical RMSE of 7-meters or less. A DEM covering the extent of the photograph is used for the rectification. The DEM is traversed from user-selected minimum to maximum X-Y values and the DEM X-Y-Z values are used to find pixel coordinates in the digitized photograph using transformations mentioned above. For each raster image cell subdivision, a brightness or gray-scale value is obtained using nearest neighbor, bilinear, or cubic convolution resampling of the scanned image. The pixel processing algorithm is indicated in the header file. An inverse transformation relates the image coordinates referenced to the fiducial coordinate space back to scanner coordinate space. Rectification Process: The photo control points and focal length are interactively fitted to their conjugate ground control points using a single photo space resection equation using Instantaneous Simultaneous Bundle Block Adjustment (ISBBA). From this mathematical fit is obtained a rotation matrix of constants about the three axes of the camera. This rotation matrix can then be used to find the photograph or camera coordinates of any other ground X-Y-Z point. Next a two dimensional fit is made between the measured fiducial marks on the digitized photograph and their conjugate camera coordinates. Transformation constants are developed from the fit and the camera or photo coordinates are used in reverse to find their conjugate pixel coordinates on the digitized photograph. Quality Control: All data is inspected according to a quality control plan at both the contractor (Earth Data International) and producer (Maryland Department of Natural Resources).
Process_Date: 19950301
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Kenneth M. Miller
Contact_Organization: Maryland Department of Natural Resources
Contact_Position:
Chief, Spatial Data Production Services, GIS Division
Contact_Address:
Address_Type: Mailing and Physical Address
Address: 580 Taylor Avenue
Address: Tawes State Office Building E-2
City: Annapolis
State_or_Province: Maryland
Postal_Code: 21401-
Country: USA
Contact_Voice_Telephone: (410) 260-8751
Contact_TDD/TTY_Telephone: (410) 260-8835
Contact_Facsimile_Telephone: (410) 260-8759
Contact_Electronic_Mail_Address: kenmiller@dnr.state.md.us
Hours_of_Service: 8:00 a.m. to 5:00 p.m. Monday - Friday
Process_Date: 19950301
Process_Time: Unknown
Cloud_Cover: 0
Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:
Raster_Object_Type: Pixel
Spatial_Reference_Information:
Entity_and_Attribute_Information:
Overview_Description:
Entity_and_Attribute_Overview:
For the color-infrared (CIR) DOQ's there are three separate 8-bit greyscale rasters representing the red (infrared), green (visible red), and lue (visible green) bands. Each band has a number from 0-255.
Entity_and_Attribute_Detail_Citation: Maryland Department of Natural Resources
Distribution_Information:
Distributor:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Kenneth M. Miller
Contact_Organization: Maryland Department of Natural Resources
Contact_Position:
Chief, Spatial Data Production Services, GIS Division
Contact_Address:
Address_Type: Mailing and Physical Address
Address: 580 Taylor Avenue
Address: Tawes State Office Building E-2
City: Annapolis
State_or_Province: Maryland
Postal_Code: 21401-
Country: USA
Contact_Voice_Telephone: (410) 260-8751
Contact_TDD/TTY_Telephone: (410) 260-8835
Contact_Facsimile_Telephone: (410) 260-8759
Contact_Electronic_Mail_Address: kenmiller@dnr.state.md.us
Hours_of_Service: 8:00 a.m. to 5:00 p.m. Monday - Friday
Distribution_Liability:
These data are governed by a license agreement. Please contact the custodian for a license agreement.
Metadata_Reference_Information:
Metadata_Date: 19990111
Metadata_Review_Date: 19990113
Metadata_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Kenneth M. Miller
Contact_Organization: Maryland Department of Natural Resources
Contact_Position:
Chief, Spatial Data Production Services, GIS Division
Contact_Address:
Address_Type: Mailing and Physical Address
Address: 580 Taylor Avenue
Address: Tawes State Office Building E-2
City: Annapolis
State_or_Province: Maryland
Postal_Code: 21401-
Country: USA
Contact_Voice_Telephone: (410) 260-8751
Contact_TDD/TTY_Telephone: (410) 260-8835
Contact_Facsimile_Telephone: (410) 260-8759
Contact_Electronic_Mail_Address: kenmiller@dnr.state.md.us
Hours_of_Service: 8:00 a.m. to 5:00 p.m. Monday - Friday
Metadata_Standard_Name:
FGDC Content Standards For Digital Geospatial Metadata
Metadata_Standard_Version: June 8, 1994
Generated by mp on Thu Sep 16 14:09:49 1999