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U.S. Geological Survey Data Series 651

Navigation Data and Maps


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Flight Path Maps

Flight path maps were created with ESRI ArcGIS 9.2 software, exported to Adobe Illustrator CS4 for further editing, and saved in JPEG format. These images can be accessed through the links provided below or from within the maps folder.

The flight path is broken up into 5-min segments, which were used to create 5-min contact sheets containing thumbnail images of photographs obtained during the survey. The flight path maps contain links to the 5-min contact sheets for each of the segments. Refer to table 1 and table 2 for details of the northern and southern county photographs, respectively.

NOTE: The survey's full-size photographs have been split up into two discs, northern counties (Disc 1) and southern counties (Disc 2) (see full survey area map). Each disc contains a KML file with links to the related full-size photographs.


Google Earth Map

The KML files were created using CreateKML JavaScript (written by Nathaniel Plant, USGS - St. Petersburg, FL, and Ann Marie Ascough, formerly contracted at the USGS - St. Petersburg, FL). The KML can be accessed through the link provided below or from within the google_earth folder. This folder also contains a Google Earth Map readme file. For more information about the JavaScript, refer to the Software page.

To link to the 5-min contact sheet photographs associated with this storm, please go to the photos folder.

The navigation document used to create the Google Earth maps provided in this report can be found in the navigation folder. The storm track layer on the KML originated from NOAA (http://csc.noaa.gov/hurricanes/#). The points on the flight path in the KML contain a link to the full-size photograph and a link to the 5-min contact sheet to which that image correlates. Refer to table 1 and table 2 for details of the northern and southern county photographs, respectively.

Google Earth setup for viewing the KML file: For PC and Mac, open Google Earth Preferences and click on the General Tab. "Allow placemark balloons to access local files and personal data" must be enabled.

NOTE: The survey's full-size photographs have been split up into two discs, northern counties (Disc 1) and southern counties (Disc 2) (see full survey area map) (Internet version unaffected). Each disc contains a KML file with links to the related full-size photographs.


Processed Navigation

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

The first was a continuous ASCII text file from the PLGR that recorded only latitudes and longitudes for the entire flight at 30-sec 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. The video subtitles recorded latitude, longitude, and time in hours, minutes, and seconds. 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 5 min and these values were matched to the latitude and longitude in the PLGR file. Then the time was interpolated between these 5-min fixes using Excel to produce a 1-sec time value record for the entire flight.

A Nikon MF-14 data back marks the time each photograph was acquired on the lower right corner of the image in day, hour, and minute format.  These values were entered from the photographs into an Excel spreadsheet. It is assumed for the purposes of locating the images 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 19:00:00, we assume that a picture was taken every 4 sec.  The photographs are assigned the time values 19:00:00, 19:00:04, 19:00:08, and so on. As a result, it should be noted that the positions assigned to each photograph are an estimate of the aircraft position, not the location of the landmark photographed. 

The time values were then cross-referenced to the interpreted latitude and longitude values discussed above to assign positions to each photograph.

The processed navigation file can be accessed from within the navigation folder or by clicking the following link: 04cch01.csv (287-KB CSV file). The following file contains 12 fields that are defined as follows:

Field 1: Latitude
Field 2: Longitude
Field 3: HR_MIN_SEC
Field 4: Slide
Field 5: Slide_URL
Field 6: Contact_Pr
Field 7: Year
Field 8: Month
Field 9: Day
Field 10: Pre_Post
Field 11: Storm
Field 12: Geo_Area


Raw Navigation

Navigation was extracted from a Rockwell Collins PLGR unit, which recorded a continuous ASCII text file from the PLGR. Locations were recorded at a 30-sec interval. No time data were collected.

The raw navigation file can be accessed from within the navigation folder or by clicking the following link: 04cch01plgr.txt (33-KB ASCII text file). The following file contains 10 fields separated by a space that are defined as follows:

Field 1: Number
Field 2: Auto Number
Field 3: Projection
Field 4: Latitude
Field 5: Longitude
Field 6: Altitude
Field 7: Feet
Field 8: Datum
Field 9: Unknown
Field 10: Sea Level


Manually Extracted Navigation

Navigation and time were manually extracted from the video footage using a Trimble Centurion GPS, which was shot continuously during the survey every 5 min, and these values were matched to the latitude and longitude in the PLGR file.

The manually extracted navigation file can be accessed from within the navigation folder or by clicking the following link: 04cch01mnl.csv (4-KB CSV file). The following file contains six fields separated by a space and defined as follows:

Field 1: Latitude Degree
Field 2: Latitude Minutes
Field 3: Longitude Degree
Field 4: Longitude Minutes
Field 5: HR:MIN:SEC
Field 6: Day/Month/Year


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