Identification_Information:
  Citation:
    Citation_Information:
      Originator: Philip A. Davis
Publication_Date: 2013
      Title: SE36112D4_SP_NAD83_Z202_NC.tif
Geospatial_Data_Presentation_Form: remote-sensing image
      Series_Information:
        Series_Name: Data Series
        Issue_Identification: DS 780
      Publication_Information:
        Publication_Place: Reston, Virginia
        Publisher: U.S. Geological Survey
      Online_Linkage: http://pubs.usgs.gov/ds/780/
      Larger_Work_Citation:
        Citation_Information:
          Originator: Philip A. Davis
Publication_Date: 2013
          Title: Natural-Color and Color-Infrared Image Mosaics of
the Colorado River Corridor in Arizona Derived from the May 2009
Airborne Image Collection
          Geospatial_Data_Presentation_Form: remote-sensing image
          Series_Information:
            Series_Name: Data Series
            Issue_Identification: 780
          Publication_Information:
            Publication_Place: Reston, Virginia
            Publisher: U.S. Geological Survey
          Online_Linkage: http://pubs.usgs.gov/ds/780/
Description:
    Abstract: The image data in this Data Series (DS) consist of 
high-resolution airborne natural-color (NC) and color-infrared
(CIR) image mosaics of the Colorado River corridor in Arizona. The 
mosaics were constructed using ADS40 SH52 multispectral imagery acquired
in May 2009 and processed by the U.S. Geological Survey (USGS). 
The SH52 data consist of a four-band image (blue, green, red, and near-
infrared wavelength bands) with a 20-centimeter (cm) resolution.
Images used for the area of interest were selected based on the
least cloud, shadow, and surface smearing. The final image mosaics
for the area of interest were subdivided into 143 image tiles because
of the large size of the image mosaic at 20-cm resolution. The image
tiles correspond to quarter-quarter-quadrangle or quarter-quadrangle
boundaries of the standard USGS map scheme.
    Purpose: These image mosaics were prepared by the USGS to provide
scientists and the general public with useful data for mapping surface
materials and geomorphic features and for determining changes with time. 
  Time_Period_of_Content:
    Time_Period_Information:
      Multiple_Dates/Times:
        Single_Date/Time:
          Calendar_Date: 200906
    Currentness_Reference: ground condition
  Status:
    Progress: Complete
    Maintenance_and_Update_Frequency: As needed
  Spatial_Domain:
    Bounding_Coordinates: 
      West_Bounding_Coordinate: -112.438698
      East_Bounding_Coordinate: -112.423897
      North_Bounding_Coordinate: 36.396618
      South_Bounding_Coordinate: 36.388916
  Keywords:
    Theme:
      Theme_Keyword_Thesaurus: 
http://geology.usgs.gov/tools/metadata/standard/glossary.html
      Theme_Keyword: Colorado River
      Theme_Keyword: Ecosystem Monitoring
      Theme_Keyword: ADS40 SH52
      Theme_Keyword: Remote Sensing
    Place:
      Place_Keyword_Thesaurus: http://geonames.usgs.gov/
      Place_Keyword: Colorado River Corridor, Arizona
  Access_Constraints: See "Use Constraints" Section
  Use_Constraints: None
  Point_of_Contact:
    Contact_Information:
      Contact_Person_Primary:
        Contact_Person: Philip A Davis
        Contact_Organization: U.S. Geological Survey
      Contact_Position: Research Geologist
      Contact_Address:
        Address_Type: mailing address
        Address: 2255 N. Gemini Drive, Building 4
        City: Flagstaff
        State_or_Province: AZ
        Postal_Code: 86001
        Country: USA
      Contact_Voice_Telephone: 928-556-7084
      Contact_Facsimile_Telephone: 928-556-7092
      Contact_Electronic_Mail_Address: pdavis@usgs.gov
  Browse_Graphic:
    Browse_Graphic_File_Name: Colorado_River_Image_Index_Map_Zone3.jpg
    Browse_Graphic_File_Description: Location and tile structure for 
image mosaic
    Browse_Graphic_File_Type: JPEG
  Data_Set_Credit: Fugro EarthData.
  Security_Information:
    Security_Classification_System: None
    Security_Classification: Unclassified
    Security_Handling_Description: None
  Native_Data_Set_Environment: Microsoft Windows XP Version 5.1 
(Build 2600) Service Pack 3; ESRI ArcCatalog 9.3.1.3000
  Cross_Reference:
    Citation_Information:
      Originator: Philip A. Davis
      Publication_Date: 2013
      Title: Natural-Color and Color-Infrared Image Mosaics of
the Colorado River Corridor in Arizona Derived from the May 2009
Airborne Image Collection
Data_Quality_Information:
  Logical_Consistency_Report: All images used in the mosaic were 
internally calibrated to provide a consistent band reflectance 
across the region.
  Completeness_Report: This mosaic represents one map tile of the
Colorado River corridor, which has a total of 143 map tiles.
  Positional_Accuracy:
    Horizontal_Positional_Accuracy:
      Horizontal_Positional_Accuracy_Report: Positional accuracy is 
approximately 30 cm.
      Quantitative_Horizontal_Positional_Accuracy_Assessment:
        Horizontal_Positional_Accuracy_Value: 0.30
        Horizontal_Positional_Accuracy_Explanation: Horizontal
accuracy determined from visible ground-control panels and fiducial
points measured in the field.
  Lineage:
    Process_Step:
      Process_Description:
        The most recent airborne data collection in 2009 
acquired image data in four wavelength bands (blue, green, 
red, and near infrared) at a spatial resolution of 20 
cm. The image collection used the latest model
of the Leica ADS40 airborne digital sensor (the SH52), which
uses a single optic for all four bands and collects and stores
band radiance in 12-bits. Davis (2012) reported on the 
performance of the SH52 sensor and on the processing steps 
required to produce the nearly flawless four-band image mosaic
(sectioned into map tiles) for the river corridor. The final
image mosaic has a total of only 3 kilometers of  surface 
defects in addition to some areas of cloud shadow because of
persistent inclement weather during data collection. The 2009
four-band image mosaic is perhaps the best image dataset that 
exists for the entire Arizona part of the Colorado River.

        Some analyses of these image mosaics do not require the
full 12-bit dynamic range or all four bands of the calibrated
image database, in which atmospheric scattering (or haze) had
not been removed from the four bands. To provide
scientists and the general public with image products that
are more useful for visual interpretation, the 12-bit image
data were converted to 8-bit natural-color and color-infrared
images, which also removed atmospheric scattering within each
wavelength-band image. The conversion required an evaluation
of the histograms of each bands digital-number population
within each map tile throughout the corridor and the
determination of the digital numbers corresponding to the
lower and upper 1 percent of the picture-element population
within each map tile. Visual examination of the image tiles
that were given a 1-percent stretch (whereby the lower 1-
percent 12-bit digital number is assigned an 8-bit value of
zero and the upper 1-percent 12-bit digital number is
assigned an 8-bit value of 255) indicated that this stretch
sufficiently removed atmospheric scattering, which provided
improved image clarity and true natural colors for all surface
materials.

        The lower and upper 1-percent 12-bit digital numbers for
each wavelength-band image in the image tiles exhibit erratic
variations along the river corridor; the variations exhibited
similar trends in both the lower and upper 1-percent digital
numbers for all four wavelength-band images. The erratic variations
are attributed to (1) daily variations in atmospheric water-vapor
content due to monsoonal storms, (2) variations in channel water
color due to variable sediment input from tributaries, and 
(3) variations in the amount of topographic shadows within each
image tile, in which reflectance is dominated by atmospheric scattering.

        To make the surface colors of the stretched, 
8-bit images consistent among adjacent image tiles, it was
necessary to average both the lower and upper 1-percent
digital values for each wavelength-band image over 20 river
miles to subdue the erratic variations. The average
lower and upper 1-percent digital numbers for each image
tile were used to convert the 12-bit image values to 8-bit values
and the resulting 8-bit four-band images were stored as natural-color
(red, green, and blue wavelength bands) and color-infrared 
(near-infrared, red, and green wavelength bands) images in 
embedded geotiff format, which can be read and used by most 
geographic information system (GIS) and image-processing software.
The tiff world files (tfw) are provided, even though they are
generally not needed for most software to read an embedded geotiff image.  

        All image data are projected in the State Plane (SP) map
projection using the central Arizona zone (202) and the North 
American Datum of 1983 (NAD83). The map tile scheme used 
to segment the corridor image mosaic followed the standard 
USGS quarter-quadrangle (QQ) map borders, but the high 
resolution (20 cm) of the images required further quarter
segmentation (QQQ) of the standard QQ tiles, where the image 
mosaic covered a large fraction of a QQ map tile. To minimize 
the size of each image tile, each image QQQ map tile was subset 
to only include that part of the OQQ tile that had image data. 
In addition, some QQQ image tiles within a QQ map tile were 
combined when adjacent QQQ map tiles were small. Thus, 
some image tiles consist of an entire QQ map tile, some consist 
of combinations of QQQ map tiles, and some consist of a single 
QQ map tile. The final image tiles number 143, which is a large 
number of files to list on the Internet for both the natural-color 
and color-infrared images. Thus, the image tiles were placed in 
seven file folders based on the half-degree geographic boundaries 
within the study area. The map tiles in each file folder were 
compressed to minimize folder size for more efficient downloading. 
The file folders are sequentially referred to as zone 1 through zone 7, 
proceeding down river. The QQ designations of the image tiles
contained within each folder or zone are shown on the index map
for each respective zone.
        References Cited:

Davis, P.A., 2012, Airborne digital-image data for monitoring the 
Colorado River corridor below Glen Canyon Dam, Arizona, 2009--
Image-mosaic production and comparison with 2002 and 2005 image 
mosaics: U.S. Geological Survey Open-File Report 2012-1139, 82 p.,
available at http://pubs.usgs.gov/of/2012/1139/.

      Process_Description: Metadata imported.
      Source_Used_Citation_Abbreviation: F:\
SE36112D4_SP_NAD83_Z202_NC.tif.xml
      Process_Date: 20121201
      Process_Time: 10030700
  Cloud_Cover: 0%
Spatial_Data_Organization_Information:
  Direct_Spatial_Reference_Method: Raster
  Raster_Object_Information:
    Raster_Object_Type: Pixel
    Row_Count: 4310
    Row_Count: 6617
    Vertical_Count: 1
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: 202
          Transverse_Mercator:
            Scale_Factor_at_Central_Meridian: 0.999900
            Longitude_of_Central_Meridian: -111.916667
            Latitude_of_Projection_Origin: 31.000000
            False_Easting: 213360.000000
            False_Northing: 0.000000
      Planar_Coordinate_Information:
        Planar_Coordinate_Encoding_Method: row and column
        Coordinate_Representation:
          Abscissa_Resolution: 0.200020
          Ordinate_Resolution: 0.200020
        Planar_Distance_Units: meters
    Geodetic_Model:
      Horizontal_Datum_Name: North American Datum of 1983
      Ellipsoid_Name: Geodetic Reference System 80
      Semi-major_Axis: 6378137.000000
      Denominator_of_Flattening_Ratio: 298.257222
Distribution_Information:
  Distributor:
    Contact_Information:
      Contact_Organization_Primary:
        Contact_Organization: U.S. Geological Survey
      Contact_Address:
        Address_Type: mailing address
        Address: 12201 Sunrise Valley Drive
        City: Reston
        State_or_Province: VA
        Postal_Code: 20192
        Country: USA
      Contact_Voice_Telephone: 1-888-ASK-USGS (1-888-275-8747)
      Contact_Instructions: http://pubs.usgs.gov/ds/780/
  Resource_Description: Downloadable Data
  Distribution_Liability: Although these data have been processed 
successfully on a computer system at the U.S. Geological Survey, no 
warranty expressed or implied is made regarding the display or 
utility of the data on any other system, or for general or 
scientific purposes, nor shall the act of distribution constitute 
any such warranty. The U.S. Geological Survey shall not be held 
liable for improper or incorrect use of the data described and (or) 
contained herein.
  Standard_Order_Process:
    Digital_Form:
      Digital_Transfer_Information:
        Format_Name: TIFF
        Format_Version_Number: 1.0
        Format_Specification: Embedded GeoTIFF
        File_Decompression_Technique: WinZip or many common 
compression systems
    Row_Count:  85.558
      Digital_Transfer_Option:
        Online_Option:
          Computer_Contact_Information:
            Network_Address:
              Network_Resource_Name: http://pubs.er.usgs.gov/
    Fees: None
Metadata_Reference_Information:
  Metadata_Date: 20121224
  Metadata_Contact:
    Contact_Information:
      Contact_Person_Primary:
        Contact_Person: Philip A. Davis
        Contact_Organization: U.S. Geological Survey
      Contact_Position: Research Geologist
      Contact_Address:
        Address_Type: mailing address
        Address: 2255 N. Gemini Drive, Building 4
        City: Flagstaff
        State_or_Province: AZ
        Postal_Code: 86001
        Country: USA
      Contact_Voice_Telephone: 928-556-7084
      Contact_Facsimile_Telephone: 928-556-7094
      Contact_Electronic_Mail_Address: pdavis@usgs.gov
  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
