USGS Cruise DIAN 97032 Long Island, NY Inner Shelf -- Fire Island Boomer and Sparker Field Navigation Data and Shotpoint Maps

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Shot Navigation Data:

The navigation is stored in ASCII files using eight fields separated by commas. Field 1: Longitude Field 2: Latitude Field 3: Line Number Field 4: Shot Number Field 5: UTM Zone 17 Easting Field 6: UTM Zone 17 Northing Field 7: Year Field 8: Julian Day:Hr:Min:Sec

Shotpoint Navigation Files (ASCII): Area 1 | Area 2 | Area 3 | Area 4 | Area 5 Shotpoint Maps: Area 1 | Area 2 | Area 3 | Area 4 | Area 5

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Raw Navigation Data:

The raw navigation was collected  using a USGS differential GPS system (Ashtech). These files represent the data that was originally recorded on floppy disk aboard ship. The data are in NEMA format. WARNING: These data have not been checked for errors. Use with caution.

To aid viewing of the original raw navigation data, each data entry was reformatted (removing the NEMA codes) by filtering the raw data files through a UNIX awk script.. Every navigation fix from the original data has been preserved however.

The navigation is stored in ASCII files using six fields separated by tabs, with each file representing a separate julian day (i.e. feb04.txt). Navigation fixes are at 10 second intervals. The start and end of each line is marked within each reformatted navigation file.

• Field 1: date and time (julian day:hour (GMT):minute:second)
• Field 2: Latitude (decimal degrees)
• Field 3: Longitude (decimal degrees)
• Field 4: Speed (in knots, computed from the navigation)
• Field 5: Heading (in degrees, computed from the navigation, i.e. course made good)
• Field 6: Water Depth (derived from a Furuno digital echo sounder). Depths are in meters, but have not been corrected for the depth of the transducer, which was about 1 m below the sea surface

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