NAMMA DC-8 Navigation and Housekeeping (ICATS)

Table of Contents

Introduction
Campaign
File Descriptions
File Naming Convention
Navigation and Housekeeping
Mission Manager Log
Binary Data Files
Graphic Representation
Contact Information

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: https://ghrc.nsstc.nasa.gov/pub/doc/namma/namdc8nav

Campaign

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/

File Descriptions

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

File Naming Convention

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

Navagation and Housekeeping

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: https://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: 

.asc decode table
Identifier
Parameters Field Format Units
       
C
Day aaa

day of year

  Time

bb:bb:bb.bbb

hour:min:sec (UT)

  Latitude

+/-cc cc. c

degrees & minutes

  Longitude

+/-ddd dd.d

degrees & minutes

  Pitch

eee.e

deg

  Roll

ffff.f

deg

  Wind speed

ggg

knots

       
D
Wind direction

hhh

deg

  True airspeed

iii

knots

  Ground speed

jjjj

knots

  True heading

kkk.k

deg

  Driftangle

llll

deg

  Pressure altitude

mmmmm

feet

  Radar altitude

nnnnn

feet

  Dew/Frost point temperature using GE1011 hygrometer with state flagged

ooooo.o

deg C

  Dew/Frost point temperature using EG&G hygrometer with state flagged

pppp.p

deg C

       
E
Static air temperature

qqq.q

deg C

  Total air temperature

rrr.r

deg C

  IR surface temperature

sss.s

deg C

  Static air temperature,

   
  calculated

ttt.t

deg C

  Indicated air speed

uuu

knots

  Vertical speed

vvvvvv

ft/min

  Distance to go

wwwww.w

nm

  Time to go

xxxx.x

min

  Align status

yy

 
       
F
Cabin altitude

zzzzz

feet

  Pressure

JJJJ.J

mb

  Mach number

K.KKK

 
  Cross track distance

LLLLL.L

nm

  Desired track

MMMM.M

deg

  Track angle error

NNNN.N

deg

  Track angle

OOO.O

deg

  Specific humidity

P.PPP

g H20/kg air

       
G
Partial pressure H20

QQ.Q

mb

  Relative humidity with respect to ice

RR.R

%

  Relative humidity with respect to water

SS.S

%

  Saturation vapor pressure of water

TT.TT

mb

  Saturation vapor pressure of water relative to ice

UU.UU

mb

  Sun elevation in ground reference frame, refracted

VVV.V

deg

  Sun elevation in aircraft  reference frame, refracted

WWW.W deg

  Sun azimuth in ground reference frame

XXX.X

deg

  Sun azimuth in aircraft reference freme relative to the nose of the aircraft

YYYY.Y

deg

       
H
egi True Heading aaa.a 0-360 degrees
egi magnetic heading bbb.b 0-360 degrees
egi x velocity ccccc +/- 9000
  egi y velocity ddddd +/- 9000
  egi z velocity eeeee +/- 9000
  egi x acceleration fffff +/- 1100
  egi y acceleration ggggg +/- 1100
  egi z acceleration hhhhh +/- 1100
       
I
Air Data Computer Total Air Temp iii.i -99.0 to 50.0
  Rosemont Total Air Temp jjj.j -99.0 to 50.0
  Potential Temperature kkk.k -999.0 to 1000.0
  GPS Altitude MSL lllll -2000 - 70000
  S Camex Dew/Frost point mmmm.m -100.0 to 70.0
  Sun Elevation Angle wrt Earth nnn.n -90.0 to 90.0
  Sun Elevation Angle wrt Aircraft ooo.o -90.0 to 90.0
  Sun Azimuth Angle wrt Earth ppp.p 0 - 360

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:

Condition

Data was too big for parameter field
Data was too small for parameter field
Data formatting error occurred

Special Character

>
<
?

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.

Mission Manager Log

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.

Binary Data Files

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

Graphic Representation

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.

Contact Information

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/