IMAGERY: SeaMARC 1A and GLORIA sidescan sonar mosaic overview

25 meter SeaMARC 1A sidescan sonar mosaic 25 meter GLORIA sidescan sonar mosaic of study area 250 meter GLORIA mosaic for the Gulf of Mexico All imagery on this CD-ROM is available in both GEOTIFF and JPEG formats.

SeaMARC 1A mosaic
GLORIA mosaics
Enhanced and unehanced images
Available Imagery
25 m mosaics
250 m GLORIA Gulf of Mexico mosaic

SeaMARC 1A mosaic

The purpose the R/V FARNELLA cruise was to complete the field work portion of a ground-truth program focusing on a depositional lobe in the eastern portion of the Mississippi Fan.  This area had been mapped in 1985 using the GLORIA (Geologic Long-Range Inclined Asdic) sidescan sonar system.  During the first leg of this cruise, a total of 3,466 square km of  sidescan sonar data were collected utilizing the SeaMARC 1A sidescan sonar system.  The SeaMarc 1A system provided a higher resolution image compared to the GLORIA sidescan system.  The collected data were processed as part of the post-cruise data compilation and digitally mosaicked to create the 25 meter UTM projected mosaic released on this CD-ROM.

GLORIA mosaics

In addition to the SeaMARC 1A sidescan sonar mosaic, the GLORIA data for the corresponding area is also included.  The GLORIA sidescan sonar mosaics were completed in 1985.  These mosaics were produced at a 50 meter resolution in the Albers Equal Area projection and each covered a 2 degree by 2 degree area.  The SeaMARC 1A survey area covered a portion of two separate and adjacent GLORIA mosaics.  Those two mosaics were combined, re-sampled and re-projected to create a 25 meter mosaic that is registered with the SeaMARC 1A mosaic.

Additionally, a 250 m resolution mosaic of the entire GLORIA data set for the Gulf of Mexico is also available on this CD-ROM.  This image has been used in the MSFAN overview display in the ArcView project file.

Enhanced and unenhanced images

For each of the archived 25 m image data sets formats, there are two sets of images: an enhanced image and an unenhanced image. Because the dynamic range of the data sets is rather low, one set of images have been radiometrically enhanced to improve viewing.  These enhanced images are used in the Mississippi Fan views contained in the ArcView project file.  A second set of unenhanced images are available for user's who wish to enhance the imagery themselves.

25 meter mosaics

250 m GLORIA mosaic

The 250 m GLORIA mosaics are only available in an enhanced image.