IAR Twin Otter Data

NRC Twin Otter Data

Overview

The Data
Characteristics
The aircraft

The Files
Characteristics
File name and Directory Information

Data Access and Contacts
FTP Site
Points of Contact

Twin Otter data Aircraft page air boundary layer data

Overview

These data were acquired during the the SGP97 Hydrology campaign by principal investigator Ian MacPherson of NRC Canada's Institute for Aerospace Research (IAR) using IAR's Twin Otter research aircraft.
The Data

One-second average data
Run-averaged data

Characteristics

One-second average files
(all flights including soundings)

Parameters Units Description

GMT Hr,min,sec Greenwich Mean Time (hhmmss)

Latitude deg from Novatel GPS when available, else from Trimble GPS

Longitude deg

Pressure altitude m (adjusted for the day's altimeter setting)

GPSalt m (see Novatel note above)

RALT m radio altimeter height

Hdg deg T aircraft heading

WDIR deg T wind direction

WSPD mps wind speed

U mps west wind component

V mps south wind component

PRESS mb static pressure

Temp degC air temperature

Ptemp degK potential temperature

Dewpt deg C dew point temp (with big dropouts during radio transmissions)

RH20 gm/kg H20 mixing ratio (from LI-COR analyzer)

R_DP gm/kg H20 mixing ratio from dewpoint analyzer (with dropouts *)

C02PPM ppm C02 n ppm from Li-Cor

02ppb ppb ozone concentration fro TECO

Notes:
GPSalt won't be available for all flights. It comes from Novatel GPS which was inoperative on Flights 01, 15, 16, 17, 19

Radioaltimeter operates only to about 800 m altitude - will read zero if out of range.

For mixing ratio, there are two, the first from the Li-Cor, and the second from the dewpoint sensor. The Li-Cor is the preferred unit. The Dewpoint and R-DP have dropouts associated with VHF radio transmissions.

The aircraft

The research capabilities of the aircraft include:

Measurement of atmospheric turbulence and wind shear;
Measurement of vertical fluxes of heat, momentum, water vapour, carbon
dioxide, ozone and methane in boundary layer studies related to vegetation growth;
Cloud physics and weather modification studies;
Airborne sampling of gaseous and particulate pollutants, cloud water and
precipitation; and
Remote sensing of biospheric processes.

Research equipment installations on the Twin Otter include real-time digital computing and displays, modern navigation and guidance systems, state-of-the-art air data sensing, a control surface position measurement system, incident and reflected solar radiation systems, weather radar, video recording suite, laser particle spectrometers and a satellite simulator.

The Files

Characteristics

File Type One-second averages Run averages

File size in bytes 105490-1271158 598-7106

Number of files 27 27

Files per flight 1 1

Storage Requirements ~23MB ~144KB

Format ASCII ASCII

Fill value 9999.9 None

File name and directory information
The run-averaged files take the form:
ot1_sgp.xxd
where
ot means 'Otter'
'1' is a version number (in case we re-do the calcs for version-2)
xx is the Flight number.
'd' means the flux and rms data were produced from linearly detrended time histories.
The columns are identified by referring to Table 6 in my preliminary report. I
The one-second data files take the form:
data1sec.snn
where
nn is the flight number

Data Access and Contacts

FTP Site
The Twin Otter Data resides is in the following GES DISC ftp site:
SGP97 Twin Otter Data
or directly via FTP at

Points of Contact

The principal investigator for the Twin Otter data is

Ian MacPherson
NRC Ottawa, Canada
School of Environmental Sciences

E-mail : Ian.Macpherson@nrc.ca

Voice: (613)998-3014

For more information on Twin Otter Data from the GES DISC, contact:

Hydrology Data Support Team
Goddard Earth Sciences
Data and Information Services Center (GES DISC)
Code 610.2
NASA Goddard Space Flight Center
Greenbelt, Maryland 20771

E-mail : hydrology-disc@listserv.gsfc.nasa.gov

Voice: 301-614-5165
Fax: 301-614-5268

Last update:Thu Jan 28 09:34:12 EST 1999
Page Info: Hydrology Data Support Team -- hydrology-disc@listserv.gsfc.nasa.gov
Web Curator: Stephen W Berrick
NASA official: Steve Kempler, DAAC Manager -- Steven.J.Kempler@nasa.gov