Navigation Data

Two separate records of flight navigation were collected during the survey.

The first navigation record was a continuous ASCII text file from the Rockwell Collins Precision Lightweight GPS Receiver (PLGR), recording in World Geodetic System 1984 (WGS84), that recorded only latitudes and longitudes for the entire flight at 30-second intervals. No time values were recorded by the PLGR. The second navigation record was recorded in the subtitles of the video footage that was shot continuously during the survey. Navigation (latitude and longitude) and time (hours, minutes, and seconds in Coordinated Universal Time [UTC]) were continuously imprinted on the video throughout the flight by a Trimble Centurion GPS (recieving in WGS84) and a Compix Video Titler. In order to produce a digital record of the navigation that included time, the latitude, longitude, and time were manually extracted from the video every 1 to 5 minutes and these values were matched to the latitude and longitude in the PLGR file. Using Microsoft Excel 2011, the time values for the remaining navigation fixes were interpolated between the known values.

A Nikon MF-14 Data Back used on the Nikon F3 camera marked the date (day of month) and time (hr:min) on the lower right corner of the 35-millimeter (mm) color positives (slide). These values were entered from the photographs into a Microsoft Excel spreadsheet. It was assumed that the photographs were taken at a constant rate during any given minute of flight. To assign a time value in seconds to each photograph, the number of photographs taken during each minute was evenly distributed across that minute. For example, if 15 photographs were taken during minute 19:00, it was assumed that a picture was taken every 4 seconds. The photographs were then assigned the time values 19:00:00, 19:00:04, 19:00:08, and so on. Latitude and longitude positions were assigned to each photograph based on the time assigned to the photograph. Next, the image positions along the coast were plotted using Google Earth. The times of the photographs were adjusted as needed to account for pauses in image collection (for example, at inlets and between islands), re-entered into the Excel spreadsheet, and new positions were assigned to each photograph.

A Nikon D1X was also used during this flight. The time of the photographs taken with the D1X were recorded in the image header. The camera's internal clock was synchronized to UTC. Photographs were named according to the time they were captured, and then associated with GPS positions according to the time of capture.

Processed Navigation

The processed navigation file can be accessed from within the nav folder or by clicking the following link to the comma-separated value (CSV) file: ds1033_05CCH02.csv. The file contains 12 fields that are defined as follows:

Field 1: LONGITUDE: estimated longitude (decimal degree, position of aircraft)
Field 2: LATITUDE: estimated latitude (decimal degree, position of aircraft)
Field 3: HR_MIN_SEC: hour_minute_second (UTC)
Field 4*: IMAGE (F3): image filename (year_monthday_r###_s##.jpg, where "r" is the roll number and "s" is the frame number)
Field 4*: IMAGE (D1X): image filename (yyyy_mmdd_hhmmssd.jpg)
Field 5: IMAGE_URL: location of the image internal to the data series
Field 6: CONTACTSHEET_URL: location of the contact sheet within the data series report
Field 7: YEAR: year the photograph was taken
Field 8: MONTH: month the photograph was taken
Field 9: DAY: day the photograph was taken
Field 10: PRE_POST: type of survey conducted (pre- or post-storm)
Field 11: STORM: baseline or name of the storm
Field 12: GEO_AREA: locations surveyed

* - The format for Field 4 depends on the camera used to capture the image. Both formats are found in Field 4.

Raw Navigation

Navigation was extracted from a Rockwell Collins PLGR unit, which recorded a continuous ASCII text file throughout the survey. Locations were recorded at a 30-second interval. No time data were collected. The raw navigation files can be accessed from within the nav folder or by clicking the following link to the text (TXT) file: ds1033_05CCH02_0831_plgrgov.txt (text file). The file contains 12 fields (separated by commas) that are defined as follows:

Field 1: NUMBER: sequential number
Field 2: WAYPOINT NUMBER: waypoint sequential number
Field 3: L/L-dms: text Latitude/Longitude: degrees, minutes, seconds (no value)
Field 4: LONGITUDE: degrees, minutes, decimal seconds (position of aircraft)
Field 5: LONGITUDE: decimal degrees (position of aircraft)
Field 6: ALTITUDE: altitude in feet
Field 7: "m": altitude in meters (no value)
Field 8: DATUM: "WGD" (World Geodetic Datum)
Field 9: "W0000.0": text, unknown meaning
Field 10: "Mil": text, unknown meaning
Field 11: "MSL": text, mean sea level (no value)
Field 12: "47": text, unknown meaning