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Short Citation:
Office for Coastal Management, 2023: 2013 Athens-Clarke County, Georgia Imagery,

Item Identification

Title: 2013 Athens-Clarke County, Georgia Imagery
Short Name: AthensClarkeOrtho
Status: Completed
Publication Date: 2013-08-08

This data set consists of 0.5 foot pixel resolution, four band (RGB, Near IR) orthoimages covering Athens-Clarke Georgia. An orthoimage is remotely sensed image data in which displacement of features in the image caused by terrain relief and sensor orientation have been mathematically removed. Orthoimagery combines the image characteristics of a photograph with the geometric qualities of a map. The design accuracy is estimated not to exceed +/- 2.5 feet CE95 of the position on the ground. Each orthoimage provides imagery over a 5,000-foot by 5,000-foot block on the ground. There is no image overlap between adjacent files. The projected coordinate system is State Plane GA West (FIPS 1002) with a NAD83 Datum and units are a US Foot. The Athens-Clarke County's and Statewide Georgia tiling schemas was used.


This data depicts geographic features on the surface of the earth. It was created to provide easily accessible geospatial data which is readily available to enhance the capability of Federal, State, and local emergency responders, as well as plan for homeland security efforts. This data also supports impervious surface mapping.




Theme Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Science Keywords
Global Change Master Directory (GCMD) Science Keywords
Global Change Master Directory (GCMD) Instrument Keywords Earth Remote Sensing Instruments > Passive Remote Sensing > Photon/Optical Detectors > Cameras > CAMERAS
Global Change Master Directory (GCMD) Platform Keywords Aircraft > AIRCRAFT
ISO 19115 Topic Category imageryBaseMapsEarthCover
None 0.5 foot orthoimage
None four-band orthophoto
None image map
None orthoimage
None orthophoto
None rectified image
None rectified photograph
None Remotely Sensed Imagery/Photos

Spatial Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Location Keywords
None Athens
None Clarke
None Georgia

Physical Location

Organization: Office for Coastal Management
City: Charleston
State/Province: SC

Data Set Information

Data Set Scope Code: Data Set
Maintenance Frequency: Unknown
Data Presentation Form: Image (digital)
Entity Attribute Overview:

Four band orthoimagery is organized in four color bands or channels which represent the red, green, blue (RGB) and Near Infrared (NIR) portions of the spectrum. Each image pixel is assigned a quadruplet of numeric values, one for each color band. Numeric values range from 0 to 4096. Areas where data is incomplete due to lack of full image coverage are represented with the numeric value of 0.

Entity Attribute Detail Citation:

NOAA - OCM Contract

Distribution Liability:

Woolpert prepared the original data as set forth in the Scope of Services, in accordance with reasonable care and due diligence as set forth in this Agreement, however, due to the easily alterable nature of electronic media, files, documents, and other deliverables, Woolpert, Inc. makes no warranties, either expressed or implied, with respect to the accuracy, completeness, merchantability, or fitness for any particular purpose, including, but not limited to, use of any/all data as described within this metadata file, by any user of this data. Any use will be at the end-user's sole risk.

Data Set Credit: Photo Science, Inc.

Support Roles

Data Steward

CC ID: 633828
Date Effective From: 2013-08-08
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202


CC ID: 633830
Date Effective From: 2013-08-08
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202

Metadata Contact

CC ID: 633831
Date Effective From: 2013-08-08
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202

Point of Contact

CC ID: 633829
Date Effective From: 2013-08-08
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202


Currentness Reference: Ground Condition

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 633834
W° Bound: -83.561777
E° Bound: -83.215989
N° Bound: 34.05248
S° Bound: 33.831531

Extent Group 1 / Time Frame 1

CC ID: 633833
Time Frame Type: Discrete
Start: 2013-01-27

Spatial Information

Spatial Representation

Representations Used

Grid: Yes

Access Information

Security Class: Unclassified
Data Access Procedure: This data set is dynamically generated based on user-specified parameters.;

Data Access Constraints:


Data Use Constraints:

None. However, users should be aware that temporal changes may have occurred since this data set was collected and that some parts of this data may no longer represent actual surface conditions. Users should not use this data for critical applications without a full awareness of it's limitations. Acknowledgment of the NOAA-Office for Coastal Management would be appreciated for products derived from these data.

Metadata Access Constraints:


Metadata Use Constraints:


Distribution Information

Distribution 1

CC ID: 744672
Download URL:
File Name: Customized Download

Create custom data files by choosing area, map projection, file format, etc.

Distribution 2

CC ID: 744673
Download URL:
File Name: Bulk Download

Simple download of data files.



CC ID: 744675
URL Type:
Online Resource

Activity Log

Activity Log 1

CC ID: 633853
Activity Date/Time: 2016-05-23

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 633852
Activity Date/Time: 2017-11-14

Converted from FGDC Content Standard for Digital Geospatial Metadata (version FGDC-STD-001-1998) using '' script. Contact Tyler Christensen (NOS) for details.

Activity Log 3

CC ID: 717241
Activity Date/Time: 2018-02-08

Partial upload of Positional Accuracy fields only.

Activity Log 4

CC ID: 744674
Activity Date/Time: 2018-03-13

Partial upload to move data access links to Distribution Info.

Technical Environment


Intergraph's suite of digital mapping and orthorectification software; Microstation; ArcGIS

Data Quality


Radiometry is verified by visual inspection of the digital orthophoto. Slight systematic radiometric differences may exist between adjacent orthoimage files; these are due primarily to differences in source image capture dates and sun angles along flight lines. These differences can be observed in an image's general lightness or darkness when it is compared to adjacent orthoimage file coverages. Tonal balancing may be performed over a group of images during the mosaicking process which may serve to lighten or darken adjacent images for better color tone matching.

Horizontal Positional Accuracy:

Orthoimagery is designed to meet or exceed +/- 2.5 feet CE95.

Completeness Report:

Orthoimages are visually inspected for completeness to ensure that no gaps or image misplacements exist within and between adjacent images. These images are derived by mosaicking multiple images to ensure complete coverage. Source imagery is cloud free. Photography was flown during leaf-off in deciduous vegetation regions. Voided areas have a radiometric value of either zero (black) or 128 (uniform gray).

Conceptual Consistency:

All GeoTIFF tagged data and image file sizes are validated using commercial GIS software to ensure proper loading before being archived. This validation procedure ensures correct physical format and field values for tagged elements. Seamlines and tile edges are visually inspected. Seamline mismatches are not corrected unless the overall displacement exceeds one meter.



2013 LiDAR Surface

CC ID: 633818
Contact Name: Photo Science, Inc.
Publish Date: 2013-01-01
Extent Type: Discrete
Extent Start Date/Time: 2013
Source Contribution:

Rectification surface. | Type of Source Media: stable-base material

Ground Control Points

CC ID: 633819
Contact Name: Photo Science, Inc.
Extent Type: Discrete
Extent Start Date/Time: 2013
Source Contribution:

Ground Control Points provide a method for accuracy assessment. | Type of Source Media: stable-base material

RAW Data

CC ID: 633817
Contact Name: Photo Science, Inc.
Extent Type: Discrete
Extent Start Date/Time: 2013-01-27
Source Contribution:

Unprocessed RAW Frames along with Airborne GPS and IMU data provide the base data for the orthophotography. | Source Geospatial Form: remote-sensing image | Type of Source Media: stable-base material

Process Steps

Process Step 1

CC ID: 633820

Digital aerial imagery was obtained using a large format Z/I Digital Mapping Camera system (DMC) equipped with Airborne GPS/IMU covering the area of interest. The imagery was acquired with a 4.7244" (120 m/m) focal length at an altitude above mean terrain of 4,800' to yield a raw pixel resolution of 0.48' suitable for photogrammetric mapping and orthophoto production. The imagery was collected during leaf off conditions in the winter of 2013 under conditions free from clouds and cloud shadows, smoke, fog, haze, light streaks, snow, ice on water bodies, foliage, flooding, and excessive soil moisture. The sun angle threshold was 30. The imagery consisted of panchromatic, blue, green, red and near infrared bands. The three color bands and near infrared bands have been pan sharpened and archived as frame imagery.

Process Date/Time: 2012-01-01 00:00:00
Source: RAW Data

Process Step 2

CC ID: 633821

Utilizing all four pan-sharpened bands [blue (B), green (G), red(R) and near infrared (IR)] digital orthorectification was performed using cubic convolution algorithm resulting in a spatial and radiometric transformation of the digital image from line/sample space into the Georgia West State Plane Coordinate System, NAD 83, US Survey Feet. The interior and exterior orientation parameters from the aerotriangulation process were used to project each pixel into the ground coordinate system, while the ortho grade DEM/DTM was used to correct for relief displacement. Radiometric correction software and techniques were used to create orthophoto files that minimize the appearance of image seams and without loss of feature signature. Orthophotos are checked for geometric accuracy, image quality and tonally balanced to produce a uniform contrast and tone across the entire project. The individual overlapping orthophoto frames were mosaicked together and the final tiles were extracted from the image set to adhere to the Athens-Clarke County 5,000' x 5,000' tiling scheme consisting of 207 individual ortho tiles in GeoTIFF format. The ortho photos are designed to meet a horizontal accuracy of 2.5 feet or less at 95% confidence level.

Process Date/Time: 2012-01-01 00:00:00
Source: 2013 LiDAR Surface

Catalog Details

Catalog Item ID: 48414
GUID: gov.noaa.nmfs.inport:48414
Metadata Record Created By: Anne Ball
Metadata Record Created: 2017-11-14 14:46+0000
Metadata Record Last Modified By: SysAdmin InPortAdmin
Metadata Record Last Modified: 2022-08-09 17:11+0000
Metadata Record Published: 2018-03-13
Owner Org: OCM
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Last Review Date: 2018-03-13
Metadata Review Frequency: 1 Year
Metadata Next Review Date: 2019-03-13