GRIP DC-8 Navigation and Housekeeping Data

Table of Contents

Introduction

The DC-8 is outfitted with a navigational recording system which in combination with REVEAL provides detailed flight parameters such as airspeed, altitude, roll/pitch/yaw angles, ground speed, flight level wind speed, temperature and many others.

The Research Environment for Vehicle-Embedded Analysis on Linux (REVEAL) system is a configurable embedded system for facilitating integration of instrument payloads with vehicle systems and communication links. REVEAL systems currently serve as onboard data acquisition, processing, and recording systems. NASA has Altair-Class REVEAL systems operating on several airborne science platforms, including ER-2, DC-8, WB-57F, P-3B Orion and G-III. This class of full-featured instrument is roughly the size of a loaf of bread and weights 10-20 lbs.

Campaign

The Genesis and Rapid Intensification Processes (GRIP) experiment was a NASA Earth science field experiment conducted August 5 to September 30, 2010. The major goal was to better understand how tropical storms form and develop into major hurricanes. NASA used the DC-8 aircraft, the WB-57 aircraft and the Global Hawk Unmanned Airborne System (UAS), configured with a suite of in situ and remote sensing instruments that were used to observe and characterize the lifecycle of hurricanes. This campaign also capitalized on a number of ground networks and space-based assets, in addition to the instruments deployed on aircraft from Ft. Lauderdale, Florida ( DC-8), Houston, Texas (WB-57), and NASA Dryden Flight Research Center, California (Global Hawk). More information about this Campaign can be found on the GRIP web site :https://ghrc.nsstc.nasa.gov/home/field-campaigns/grip

The DC-8 REVEAL transfer of housekeeping data allows easy access to aircraft data by experimenter-operated computers. The data were transferred at one second intervals.

Most flights have the four files listed below. There is a mission monitor log (ASCII), which records important flight events, a raw and a quality controlled navigation and housekeeping file (ASCII), which contain detailed aircraft information. There is also a flight track kml file, which when used with Google Earth, shows the complete aircraft flight path.

The navigational and housekeeping files are named following the examples below:

GRIP_DC8_ASCII_flightxx_ddMonyyyy-tttt_NAV.txt

GRIP_DC8_CompleteTrack_flightxx.kml

GRIP_DC8_MissionLog_flightxx_ddMonyyyy.log

GRIP_DC8_QC_NAV_flightxx_ddMonyyyy.csv

where:

xx = GRIP flight number (1-15)
dd = day
Mon = month in three characters (Aug, Sep)
yyyy = year
tttt = time in hour, minute
txt = ascii text file
csv = comma-seperated value, contains a comma delimiter (for use in excel)
kml = Keyhole Markup Language, used for google earth display
log = an ascii type log file

GRIP_DC8_ASCII_flightxx_ddMonyyyy-tttt_NAV.txt

Detailed aircraft information is contained in these serial output (ASCII) files. This format shows seven lines, which are repeated every one second of the flight.

C aaa bb:bb:bb.bb +cc cc.c +ddd dd.d eee.e ffff.f ggg
D hhh iii jjjj kkk.k lll.l mmmmm nnnnn ooooo.o ppppp.p
E  qqq.q rrr.r sss.s ttt.t uuu vvvvvv wwwww.w xxxx.x yy
F  zzzzz JJJJ.J K.KKK LLLLL.L MMMM.M NNNN.N 000.0 P.PPP
G QQ.Q RR.R SS.S TT.TT UU.UU VVV.V WWW.W XXX.X YYYY.Y
H aaa.a bbb.b ccccc ddddd eeeee fffff ggggg hhhhh
I   iii.i jjj.j kkkk.k lllll mmmm.m nnn.n ooo.o ppp.p

These files may be decoded using the following table:

All data parameters are in engineering units. For integer formats, the number of digits in a field may vary from one to the number shown in the field format. For non-integer formats, the placement of the decimal point within the field and the number of digits to the right of the decimal point are guaranteed as illustrated in the field format. However, the number of digits to the left of the decimal point may vary from one to the number shown in the field format. Unused leading digits are padded with either blanks or zeroes. Units are not included in the data stream.

Individual parameter fields will be filled with special characters for the following reasons:

Additionally, invalid or unavailable data may be replaced by question marks (?), however, the absence of question marks in a parameter field does not guarantee the validity of the data.

Navigation and Housekeeping Quality Controlled Data Files

GRIP_DC8_QC_NAV_flightxx_ddMonyyyy.csv

These NAV data files have been quality controlled and are in comma-seperated value format (ascii). The data are displayed in columns with labels in the following order:

UTC
Latitude
Longitude
GPS_Altitude
Pressure_Altitude
Radar_Altitude
Ground_Speed
True_Air_Speed
Indicated_Air_Speed
Mach_Number
Vertical_Speed
True_Heading
Track_Angle
Drift_Angle
Pitch_Angle
Roll_Angle
Static_Air_Temp
Dew_Point
Dew_Point-3_Stage
TAT_Aircraft
TAT_Experimenter
IR_Surf_Temp
Static_Pressure
Cabin_Pressure
Wind_Speed
Wind_Direction
Solar_Zenith_Angle
Aircraft_Sun_Elevation
Sun_Azimuth
Aircraft_Sun_Azimuth
Mixing_Ratio
Part_Pressure_H2O
Part_Pressure_Ice
H2O_Sat_VP_Water
H2O_Sat_VP_Ice
Rel_Humidity_H2O
Rel_Humidity_Ice

GRIP_DC8_MissionLog_flightxx_ddMonyyyy.log

These are plain text messages which record important events during the flight. They are the managers time stamped commentary of observations during the flight, annotating them with time, position, altitude, and other information.

Graphic Representation

GRIP_DC8_CompleteTrack_flightxx.kml

In addition to the text version of flight data, a kml file has been included to display flight paths during the course of the flight using Google Earth.

The data producer is:

David Van Gilst
DC-8 Network Engineer
National Suborbital Education and Research Center
University of North Dakota

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/