Research focused on the importance of Louisiana Marshes considering that In human terms for 2002, 30% commercial fisheries landings in United States was from Louisiana, amounting to Over 1 billion pounds, and $343 million, while to nekton, this provides, nursery habitat and that Flooded marsh and Submerged aquatic Vegetation (SAV) surrounding the marsh provide both food and protection for early life history stages.

In addition, high-resolution imagery for the Gulf of Mexico in the proximity of Davis Pond region, the Chandeleur Islands and Lake Ponchartrain was to be obtained from airborne remotely sensed data.  The PI’s approached Geo Tek-Duncan Multi-Spectral Imaging System, a company based at John C. Stennis Space Center to assist in data acquisition. We have done our first aircraft flight of hyper-spectral high-resolution sensors.  Coordination of this effort inside John C. Stennis Space Center is currently being accomplished by Dr. Jinchun Yuan who currently serves as the Post doctorate Associate for the Fisheries Habitat Research Thrust component.  The first flight over a selected location of the Davis Pond region was arranged with Geo-Tek Duncan Multi-Spectral Imaging System.  The flight is expected to has generate remotely sensed data using four bands: (1) Green (510-580 nm) (2) Red (635-690nm) (3) Near-IR (750-900nm), and Blue (Interpolated).  The spatial resolution in a 1920 X 1080 pixel array at 6,000 feet is 1m, and at 12,000 feet, it is 2.12m.  Data to be generated is co-registered with GPS integration.  On March 3, 2004 the following research team will meet face-to-face with Geo-Tek-Duncan Multi-Spectral Imaging System owners at LSU to plan airborne test flights of the Davis Pond region.  In the same areas satellite data identified at Stennis by Dr. Yuan outlined the availability of Landsat 7 data using 28.5N, 91W and 30.5N, 88.5W, 34 Landsat 7 data files for Gulf of Mexico areas in South Louisiana.  This data is being downloaded from TerrSoar 4.1; it is downloaded at the following website: ftp://moray.dms.usm.edu/cczars/.  The data, covering a ten-year span, beginning in 1989 will greatly compliment the Fisheries Habitat research thrust’s data needs.


Remote Sensing and Ground-Truth Activities in the Davis Pond Diversion-Barataria System and Other Coastal Environments

On Friday, March 18, 2005 the first of a series of hyperspectral data collections from aircraft occurred. Geotek, Stennis (Daniel Lee) was contracted to collect data from several key lines in coastal Louisiana (Figure 1). Data collection included the Davis Pond diversion into Lake Catouatche, the middle and eastern section of Lake Salvador including floating marsh environments, the southern portion of Barataria Bay (where LSU has a monitoring station) and three transects for the mapping of submerged aquatic vegetation (SAV). A visible/near infrared hyperspectral system (VNIR 100E) was contracted from the Institute for Technology Development (David Lewis). This sensor provides 12-bit data in130 bands between 400 and 1000 nm. The lines were flow between 9:00 and 11:30 CDT.

As this sensor is not calibrated, calibration targets were chosen at the east end of Grand Isle, based on discussions with Greg Carter (Gulf Coast Geospatial Center, GCRL, Ocean Springs, MS). These targets were identified two weeks prior to the flight. Dr. Nan Walker (LSU) and research assistant, Shreekanth Balasubramanian, collected the calibration data simultaneous with collection of calibration lines by the aircraft (Figure 2). The main calibration targets were a large unmarked asphalt parking lot and a concrete parking lot, within a new marina development, west of the Coast Guard station. The calibration data were collected with a GER-1500 spectro-radiometer. In addition to the calibration scans, measurements were obtained from the coastal ocean (from the State Park fishing pier), the adjacent Grand Isle Beach, and the beach vegetation. Target reflectances were computed from the radiance data and will be used to calibrate the 12-bit data from the hyperspectral sensor. This calibration will enable comparison of the March 18, 2005 data with future measurements.

The initial data collection exercise will be used to select the lines to be flown repeatedly over the next few years. Our uses of the data are wide-ranging including mapping change in vegetation on land, detection and quantification of suspended sediments, chlorophyll a and other pigments in water, and detection and mapping of submerged aquatic vegetation. During future hyperspectral collection missions, additional collection of “ground?truth measurements will be obtained to quantify in-water substances within the Davis Pond diversion to develop methods for the quantification of suspended sediments and chlorophyll a from the hyperspectral data.

In September 2004, LSU Coastal Studies Institute started making continuous measurements of temperature, salinity, water level, optical backscatter, and fluorescence in southern Barataria Bay. These data provide important time-series information that will be used to assess environmental change and to assist in the interpretation of satellite measurements of suspended sediments (from MODIS) and chlorophyll a (from Oceansat OCM). The optical backscatter and fluorescence measurements from the first deployment in September/October 2004 are shown in Figure 3. The LSU station is located on a platform alongside USGS sensors in southern Barataria Bay (Figure 4). The location of another important water monitoring station in the northern portion of the Barataria system, closer to the inflow of river waters from the Davis Pond structure is also shown in Figure 4.

 

Figure 1.  Selected lines along which hyperspectral data were obtained on 18 March 2005.

Figure 2.  Calibration lines flown across the east end of Grand Isle on 18 March 2005.

Figure 3.  Time-series data from the LSU station in southern Barataria Bay (Location, Figure 4) in September and October 2004 (top) optical backscatter showing re-suspension of sediments during cold front passage events and (bottom) fluorescence showing a period of elevated chlorophyll a that was not correlated with suspended sediment events.

Figure 4.  Locations of key monitoring stations in the Davis Pond diversion-Barataria system where measurements of temperature, salinity, water level, optical backscatter and fluorescence are being recorded by LSU, USGS, and DNR.

Figure 5.  GEO-TEK  First look Hyperspectral Imagery

Figure 5b.  GEOTEK “First Look"