NAMMA DC-8 Navigation and Housekeeping (ICATS)

Table of Contents

Introduction

The DC-8 Information Collection and Transmission System (ICATS) processes and archives avionics and environmental parameters from the Navigational Management System, GPS, Central Air Data Computer, Embedded GPS/INS, and analog voltage sources from the aircraft and experimenters. They include measurement of aircraft parameters such as airspeed, altitude, roll/pitch/yaw angles, ground speed, flight level wind speed, temperature and many others.

An indepth discription of ICATS, and  a complete breakdown of each measured parameter may be found in the following three documents: ICATS_format_readme.txt, DC8_Handbook-3.pdf and ICATS_appendix_2.pdf. These documents may obtained via ftp from: ftp://ghrc.nsstc.nasa.gov/pub/doc/namma/namdc8nav

These data files were generated during support of the NASA African Monsoon Multidisciplinary Analyses (NAMMA) campaign, a field research investigation sponsored by the Science Mission Directorate of the National Aeronautics and Space Administration (NASA). This mission was based in the Cape Verde Islands, 350 miles off the coast of Senegal in west Africa. Commencing in August 2006, NASA scientists employed surface observation networks and aircraft to characterize the evolution and structure of African Easterly Waves (AEWs) and Mesoscale Convective Systems over continental western Africa, and their associated impacts on regional water and energy budgets. For more information about the NAMMA Campaign, go to the NAMMA web site: http://namma.nsstc.nasa.gov/

The DC-8 ICATS serial transfer of housekeeping data allows easy access to aircraft data by experimenter-operated computers. The data were transferred at one second intervals. Image files of in flight parameters are generated and saved as post-script files, as are flight track maps .

Most flights will have the six files listed below. There are two binary format data files, one at 1 Hz, and another at 10 Hz sample rate. There is a mission monitor log (ASCII), which records important flight events , and a navigation and housekeeping file (ASCII), which contains detailed aircraft information. There are also two browse files (pdf), one is a flight track map and the other shows ICATS standard parameter plots. Additonally the 12 September 2006 file contains an RTMM (Real Time Mission Monitor) animation (.avi) which shows the flight track versus time superimposed over satellite data.

Sample Files:

NAMMA_ICATS_20060904_1HZ.bin
NAMMA_ICATS_20060904_10HZ.bin
NAMMA_ICATS_20060904_FLIGHT_MAP.pdf
NAMMA_ICATS_20060904_MMLOG.txt
NAMMA_ICATS_20060904_NAV.txt
NAMMA_ICATS_20060904_PLOTS.pdf
2006-09-12_RTMM_NAMMA.avi

The ICATS files are named following the example below:

NAMMA_ICATS_yyyymmdd_<xxxx>.ext

where:

NAMMA_ICATS = NAMMA DC-8 ICATS data
yyyymmdd = yyyy=year, mm=month, dd = day
<xxxx>= descriptive name of file
ext = format of the file

NAMMA_ICATS_2006XXXX_NAV.txt

Detailed aircraft information is contained in these serial output (ASCII) files. A detailed description of these data files can be viewed/downloaded here: ftp://ghrc.nsstc.nasa.gov/pub/doc/namma/namdc8nav/icats_format_readme.txt

The 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.

NAMMA_ICATS_2006xxxx_MMLOG.txt

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.

NAMMA_ICATS_2006xxxx_1HZ.bin

One Hz binary data of 15navigation5 parameters including , wind, waypoint, and aircraft state.

NAMMA_ICATS_2006xxxx_10HZ.bin

Ten Hz binary data of 40 navigation and waypoint data

NAMMA_ICATS_2006xxxx_FLIGHT_MAP.pdf
NAMMA_ICATS_2006xxxx_PLOTS.pdf
2006-09-12_RTMM_NAMMA.avi

In addition to the text version of flight data, a pdf plot file of many parameters has been included to display changes during the course of the flight. Also included in the dataset is a flight track map, which shows position time hacks every ten minutes. There is an RTMM animation of the flight track versus time superimposed over satellite data for 12 September 2006.

The data producer is:

Rick Shetter
NSERC, University of North Dakota
rshelter@nserc.und.edu

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/