CAMEX-4 ER-2 Navigation Data

Table of Contents

Introduction

This README file contains information about the content and structure of the ER-2 navigation files for flights in support of CAMEX-4. These data files were generated on board the ER-2, saved to disk, and downloaded post flight.

Each NAV filename has the structure: c4enav_2001.ddd_010fff.tar. In its own way, the filename is a metadata tag for the data file itself, where c4enav announces that this is navigation data from the NASA ER-2 aircraft. The year (2001) and day of year (ddd) give the start date (UTC) of the mission. The mission number (010fff) is also included in the tar file name where fff is the flight sequence number. The data for each mission is combined in a tape archive format (.tar) file so that the data may be easily disseminated.

Once 'untarred', the .tar file yields five files each named in the following manner:

• 01-fff.ASC
• 01-fff.F13
• 01-fff.PS
• 01-fff.RPT
• 01-ff_map.GIF
• 01-fff_par_1.GIF
• 01-fff_par_2.GIF

Where fff is the flight number assigned to the mission. Each of these files are detailed below.

This text file contains raw information recorded by on board navigation and data collection systems. In addition to typical navigation data (e.g. date, time, lat/lon and altitude) it contains outside meteorological parameters such as wind speed and direction and temperature. Data is collected in one second increments. While easily readable using almost any text viewer (in notepad set the font to courier and size to 8, for example) there is a better, more formatted form of flight data available.

This is that better format shown here.

The first line of data decodes as follows:

          NASA 809 - ER-2 tail number 809 belonging to NASA
          Flight #01-135 09/07/01/250 (GMT)-  01-135 is the NASA flight number
          09/07/01- DD/MM/YY , 250is the numeric day of the year, GMT-UTC on which the flight took off
          RECORDER 5HARD DISK 5- the recorder and disk the data was originally saved upon.

Lines 3 and 4 provide column headers (when properly aligned) for the data, while line 5 provides the units in which the data are reported. INU means Inertial Navigation Unit. The other abbreviations are self-explanatory. Time is in UTC.

As these data are extensive in nature and difficult to extract to fit on one page as text. Here are two methods that work. Import these data into a spreadsheet: once there you can format the cells so that the data fit to columns, then realign the column headers to reflect the pattern above. Or, open in a window, format with a small font (6 or 8 point) and put in courier style as it is a constant width font.

Commonly called 'switchology', this file describes information about the mission, pilot, date and time as well as on/off times for each of the switches which control the separate scientific instruments. If for example you knew that your instrument was in the q-bay and was powered through switch Q6, you would could easily find the times that the pilot powered up/down your instrument.
 

This is a post-script file. It contains three images two parameter graphs, and the flight track map. We have extracted these images and they are named:

• 2d1) 1-fff_par_1.GIF - first parameter graph
• 2d2) 1-fff_par_2.GIF - second parameter graph
• 2d3) 1-fff_map.GIF - flight track map

To order these data or for further information, please contact:

Global Hydrology Resource Center
User Services
320 Sparkman Drive
Huntsville, AL 35805
Phone: 256-961-7932
E-mail: support-ghrc@earthdata.nasa.gov
Web: http://ghrc.nsstc.nasa.gov/