39438
Benthic Habitats of Puerto Rico and the U.S. Virgin Islands;Photomosaic of Puerto Rico (Guayanil), 1999
pr_guayanil_photo
Data Set
Published / External
37212
VI_PR_photo
Project
Completed
2001-05-01
Habitat maps of Puerto Rico and the U.S. Virgin Islands were created by visual interpretation of aerial photographs using the Habitat Digitizer Extension. Aerial photographs are valuable tools for natural resource managers and researchers since they provide an excellent record of the location and extent of habitats. However,spatial distortions in aerial photographs due to such factors as camera angle, lens characteristics, and relief displacement must be accounted for during analysis to prevent incorrect measurements of area, distance, and other spatial parameters. These distortions of scale within an image can be removed through orthorectification. During orthorectification, digital scans of aerial photos are subjected to algorithms that eliminate each source of spatial distortion. The result is a georeferenced digital mosaic of several photographs with uniform scale throughout the mosaic. Features near land are generally georeferenced with greater accuracy while the accuracy of features away from land is generally not as good. Where no land is in the original photographic frame only kinematic GPS locations and image tie points were used to georeference the images. After the orthorectified mosaics were created, photointerpreters were able to accurately and reliably delineate boundaries of features in the imagery as they appear on the computer monitor.
The National Ocean Service is conducting research to digitally map biotic resources and coordinate a long-term monitoring program that can detect and predict change in U.S. coral reefs, and their associated habitats and biological communities.
893
Theme
ISO 19115 Topic Category
environment
Theme
ISO 19115 Topic Category
oceans
Theme
Remotely Sensed Imagery/Photos
Theme
SAV
Theme
aerial photography
Theme
benthic
Theme
coral
Theme
habitat
Theme
mangrove
Theme
oceans
Theme
reef
Theme
seagrass
Spatial
Guayanilla
Spatial
Puerto Rico
Spatial
U.S. Exclusive Economic Zone
National Centers for Coastal Ocean Science
Silver Spring
MD
Data Set
None Planned
raster digital data
Pixel values are MrSID compressions. Data were originally geoTIFF format.
MrSID Compressed orthorectified images; UTM Zone 19.
Data are not to be used for navigation.
National Geophysical Data Center
Data Steward
2001-05-01
Position
NCCOS Scientific Data Coordinator
NCCOS.data@noaa.gov
Distributor
2001-05-01
Position
NCCOS Scientific Data Coordinator
NCCOS.data@noaa.gov
Metadata Contact
2001-05-01
Position
NCCOS Scientific Data Coordinator
NCCOS.data@noaa.gov
Point of Contact
2001-05-01
Position
NCCOS Scientific Data Coordinator
NCCOS.data@noaa.gov
Principal Investigator
2001-05-01
Person
Kendall, Matt
matt.kendall@noaa.gov
Publication Date
-66.57
-66.42
18
17.53
Discrete
1999-02
Discrete
1999-03
Discrete
1999-12
Yes
Unclassified
none
none
http://coastalscience.noaa.gov/datasets/ccma/biogeo/benthic/mosaic/zip/guayanil.zip
Downloadable Data
MrSID
SID-MrSID/Multiresolution Seamless Image DB
http://ccma.nos.noaa.gov/products/biogeography/benthic/data/
Online Resource
http://coastalscience.noaa.gov/datasets/ccma/biogeo/benthic/mosaic/zip/guayanil.zip
Online Resource
2013-09-16
Date that the source FGDC record was last modified.
2017-04-05
Converted from FGDC Content Standard for Digital GeospatialMetadata (version FGDC-STD-001-1998) using 'fgdc_to_inport_xml.pl' script. Contact Tyler Christensen (NOS) for details.
2017-09-13
Partial upload of Spatial Info section only.
2017-11-01
Replaced entire Lineage section to populate new Source Contribution field.
2018-02-08
Partial upload of Positional Accuracy fields only.
MrSID Compression, orthorectified aerial photos
Horizontal accuracy was determined by solution of Socet Set generated model (RMS less than 1) and by comparison to independent ground control data. x=0.1 +/-3.0, y=0.9 +/-4.4 values are in meters +/- standard deviation
Cloud Cover: 2
No color balancing was attempted since this alters color and textural signatures in the original imagery and interferes with the photointerpreter's ability to delineate habitats. As a result mosaics have visible seams between adjacent photos. This provides the photointerpreter with "true color" imagery for maximum ability to identify and delineate benthic features.
Once all of the photographs were orthorectified, the best segments of each photograph were selected for creation of the final mosaic. Segments of each photograph were selected to minimize sun glint, cloud interference, and turbidity in the final mosaic. Where possible, parts of images obscured by sunglint or clouds were replaced with cloud/glint free parts of overlapping images. As a result, most mosaics have few or no clouds or sun glint obscuring bottom features.
National Geodetic Survey Aerial Photography of Puerto Rico and the U.S. Virgin Islands, 1999
National Oceanic and Atmospheric Administration (NOAA),National Ocean Service (NOS), National Geodetic Survey (NGS)
1999-01-01
Discrete
1999
48000
http://www8.nos.noaa.gov/biogeo_public/aerial/search.aspx
NOS aerial photos were used to create orthophotomosaics | Source Geospatial Form: raster digital data | Type of Source Media: aerial photography and scanned photos
1
Aerial photographs were acquired for Puerto Rico and the U.S. Virgin Islands Benthic Mapping Project in 1999 by NOAA Aircraft Operation Centers aircraft and National Geodetic Survey cameras and personnel. Approximately 600, color, 9 by 9 inch photos were taken of the coastal waters of Puerto Rico and the U.S. Virgin Islands at 1:48000 scale. Specific sun angle and maximum percent cloud cover restrictions were adhered to when possible during the photography mission to ensure collection of high quality imagery for the purpose of benthic mapping. Print and diapositives were created from the original negatives. Diapositives were then scanned at a resolution of 500 dots per inch(DPI) using a metric scanner, yielding 2.4 by 2.4 meter pixels for the 1:48000 scale photography. All scans were saved in TIFF format for the purposes of orthorectification and photointerpretation. Georeferencing/mosaicing of the TIFF's was performed using Socet Set Version 4.2.1. Lens correction parameters were applied to each frame to eliminate image distortion. Airborne kinematic GPS was then used when available to provide a first order geolocation. When this information was not available, measurements were made between lightline strips for input into Socet Set to provide preliminary co-registration. Image to image tie-points were then used to further co-register the imagery, especially for photos taken over open water where ground control points were not available. Fixed ground features visible in the scanned photos were selected for ground control points (GCP's)which were then used to georeference the imagery. GCP's were measured using real-time DGPS (differential Global Positioning System). Points were obtained with a wide distribution throughout the imagery, especially on peninsulas and outer islands whenever possible since this results in the most accurate registration throughout each image. Only ground control points for terrestrial features were collected due to difficulty of obtaining precise positions for submerged features. A custom digital terrain model (DTM) was then created using the Socet Set software to correct for feature displacement due to terrain effects. To accomplish this, water features and the shoreline were set to an elevation of zero. Preliminary experimentation revealed that the effects of refraction on the position of submerged features in the imagery were not significant enough to make a correction for underwater displacement according to Snell's law. Selected land elevation points were then inserted from USGS 1:24000 Digital Elevation Models or other elevation data sets where clouds or other sources of interference prevented the Socet Set software from automatically making an accurate DTM. Once the terrain models were complete and a draft orthorectified mosaic was produced, a set of independent ground control points was used to measure the quality of each mosaic's rectification and ensure that it met acceptable limits of horizontal spatial accuracy. If spatial accuracy was not acceptable based on this comparison, additional modifications were made, until a satisfactory mosaic was created for each island. In general, mosaics were georeferenced such that pixels are positioned within one pixel width of their correct location.
2000-01-01T00:00:00
gov.noaa.nmfs.inport:39438
Tyler Christensen
2017-04-05T12:52:33
SysAdmin InPortAdmin
2023-10-17T16:12:12
2018-02-08
National Centers for Coastal Ocean Science
NCCOS
1002
Public
No
2018-02-08
1 Year
2019-02-08