TCSP Aerosonde

Table of Contents

Introduction

The Aerosonde is a small, long endurance, Unmanned Aerial Vehicle (UAV) with a 3m wingspan and a full weight of about 15kg. This UAV can fly for up to 30hr and for long distances (up to 3000km). It is operated globally by Aerosonde International, with companies both in the United States and Australia. The Aerosonde was developed especially for meteorological and environmental reconnaissance over oceanic and remote areas and in harsh conditions.

The Aerosonde system was operated in 'field deployment mode' in which a specialized crew was deployed to the field to operate the aircraft locally under the direction of a Principal Investigator. In this mode, the team worked with the PI during the field program and provided all Aerosonde operations, including regulatory approvals and support services.

The Aerosonde team for the TCSP 2005 mission consisted of Brenda Mulac (Team Leader and Mission Scientist), Ryan Vu (Pilot), Dave Smith (Technician), Nick Logan (Ground control), Dave Easmunt (NASA Mission Manager), Fabian Garcia (Interpretor), and Jason Roadman (Observer). The NASA Principal Investigator was Anthony Guillory.

The TCSP Field Experiment was held during the month of July, 2005, in Costa Rica. The mission was to study the processes associated with tropical waves passing over Central America to the Pacific ocean, where they would eventually form tropical cyclones. The NASA ER2 aircraft, the NOAA P-3 aircraft, and Aerosonde were to provide complimentary measurements in and around cloud systems associated with the waves. The Aerosonde operations were based out of Quepos, located on the Pacific Coast of Costa Rica. Eight flights were successfully flown, for a total of 75 flight hours. The flights were designed to document the boundary layer both near shore and over the open ocean. Measurements of pressure, air temperature, humidity, and sea surface temperature were made during each flight. The Aerosonde Flights consisted of soundings along track from 500ft up to 8600ft and varied in length from 8 hours to 18 hours.

Data files created during the Aerosonde flights are bundled into daily files using the unix tar command, one for each flight. A typical file name is:

aerosonde_2005.188.tar

where "aerosonde" is the dataset identifier, "2005.188" is the year.'day-of-year' and ".tar" shows the type of file. Each tar file contains the following types of files:

i070726a.as
i070726a.gps
i070726a.ptu
i070726a.wnd
m070726a.txt

There are five data files associated with each flight, a PTU file (*.ptu), a wind file (*.wnd), an Aerosonde file (*.as), a GPS file (*.GPS), and a metdump file (m*.txt).

File names are of the form XmmddaaY.*, where X is a single letter indicating phase of flight (L=local, E=enroute (TDMA), R=returning, I=iridium), “mm” and “dd” are two digit numbers indicating respectively the month and day that the flight launch took place; “aa” is a two digit number identifying the aircraft that performed the flight; and “Y” is a letter used to differentiate files when an aircraft has made multiple flights on a single day (“A” for first flight of the day, “B” for second flight of the day, etc..). Note: This mission has no multiple flights per day. The naming convention of metdump files is the same as for other files, except “m” is used at the beginning of the file name in lieu of the flight phase designator. A brief description of each file type and its contents is given below:

PTU File: PTU files are comma delimited text files containing pressure (hPa), temperature (C), and relative humidity (%) data from each of the two Vaisala RS902 sensors carried onboard the Aerosonde. The first line of each file contains header information defining the contents of each column of data. Note that UTC time is given in seconds and in hours.

WND File: WND files are comma delimited text files containing the wind data from each flight. The first line of each file contains header information defining the contents of each column of data. Wind measurements are given in ms-1.

AS and GPS Files: The AS and GPS files are also comma delimited text files. The AS file contains the KT-11 SST measurements and pressure altitude. The GPS file contains latitude, longitude, and GPS altitude for the flight. Note that the time stamps for these two files are not synchronized.

Metdump File: Metdump files are comma delimited text files and contain data downloaded from the Aerosonde’s onboard meteorological computer after flight. Header information in the first line defines data in each column. The pyrometer data is provided as a raw count in the last column of this file.

Additional documentation for the Aerosonde aircraft, the missions and data collected may be found in the following documents:

Aerosonde_Data_Release_Notes_P_TCSP_July_2005.pdf
Aerosonde_TCSP_report.pdf

Here are some other useful web sites for in depth information on the Aerosonde, and the TCSP mission:

http://www.aerosonde.com
http://tcsp.nsstc.nasa.gov/tcsp
http://www.nasa.gov/vision/earth/lookingatearth/hurricane_aircraft.html
http://www.aoml.noaa.gov/hrd/HFP2005/TCSP.html

Cione, J.J., and E. W. Uhlhorn 2003: Sea surface temperature variability in hurricanes: Implications with respect to intensity change. Mon. Wea. Rev., v.131, pp.1783-1796

Wroe, D.R. and G.M. Barnes 2003: Inflow Layer Energetics of Hurricane Bonnie (1998) near Landfall. Mon. Wea. Rev. v.131 pp. 1600-1612

Cione, J.J., P. J. Black and S. Houston 2000: Surface observations in the hurricane environment. Mon. Wea. Rev, v.128 pp.1550-1561

Dunion, J.P., and C.S. Velden, 2004: The impact of the Saharan Air Layer on Atlantic tropical cyclone activity. Bull. Amer. Meteor. Soc., v.85 no. 3, pp.353-365

Data can be ordered and questions addressed at http://ghrc.nsstc.nasa.gov.

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/