Inter-Continental Atmospheric Radiosonde Upper-air Sounding

System( ICARUSS)

Hal Cole, Mel Shapiro,

Vin Lally, Terry Hock, Rolf Langland

Surface & Sounding Systems Facility (SSSF)

Atmospheric Technology Division (ATD)

National Center for Atmospheric Research * (NCAR)

Boulder, CO * The National Center for Atmospheric Research is sponsored by the National Science

Foundation

NCAR / ATD / SSSF

ICARUSS System Overview

ATLANTIC OCEAN

Zero-pressureB alloon

G ondola(24 sonde capacity)

6 hoursbetw eendrops

NORTHAMERICA

EUROPE

O rbC om mLEO S ate llite

NCAR / ATD / SSSF

Balloon System Requirements

Receive and process data from each sonde deployed.

Payload of 24 GPS sondes

Operation at 50 mb to 100 mb (~18 km)

Zero-Pressure Balloon duration up to 6 days

Sondes released at programmed intervals (6 hours typical) or on

command from ground station

Descent time of sonde ~24 minutes from 18 km.

Near-surface fall rate of ~8 m/s

Data generated for each sonde and sent via LEO satellites to

ground station

NCAR / ATD / SSSF

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PRESSURE - MB

AL

TIT

UD

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FE

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STANDARD ATMOSPHERE PRESSURE VS ALTITUDE

NCAR / ATD / SSSF

INFLATION OF POLYETHYLENE BALLOON

NCAR / ATD / SSSF

BALLOON BEING PREPARED FOR LAUNCH

NCAR / ATD / SSSF

BALLOON LAUNCHED

NCAR / ATD / SSSF

ICARUSS BALLOON LOAD VS ALTITUDE DATA

ASSUMPTIONS:1. 24 Sondes @ 300 gms2. Ballast is 36% of Gross3. Gross = Balloon + Payload + Free Lift

Alt. Ft.

Press.mb

Ballastkg

Gondolakg

Sondekg

Balloonkg

Heliumkg

Grosskg

45920 141 14.8 10 7.2 3 5.9 40.949200 120.4 14.8 10 7.2 3 5.9 40.952480 102.9 15.6 10 7.2 3 6.2 4255790 78.7 15.6 10 7.2 3 6.2 4259040 75.1 16.3 10 7.2 3 6.5 4362320 64.1 16.3 10 7.2 3 6.5 4365600 54.8 17 10 7.2 3 6.8 4468880 46.8 17 10 7.2 3 6.8 4472160 40 17 10 7.2 3 6.8 44

NCAR / ATD / SSSF

STANDARD ATMOSPHERES - TEMPERATURE VS ALTITUDE

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TEMPERATURE - C

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UD

E -

FT

POLAR

TROPICAL

STANDARD

NCAR / ATD / SSSF

Flight Train

Load attachment lines

Parachute

Satellite antenna

Balloon

Cut down

Shock absorber

Sonde receiving antenna

GPS antenna

Gondola

~~

NCAR / ATD / SSSF

Gondola Overview

4-layer Styrofoam

Sonde launch tube (24)

Ballast compartment (4)

Electronics bay

50 cm

40 cmCross-section

NCAR / ATD / SSSF

ICARUSS Sonde

GPS Antenna

GPS Receiver

Microprocessor

Battery

Radio Transmitter Pressure sensor

Hum idity sensorstemperature sensorand

Cross Parachute

NCAR / ATD / SSSF

Sonde Description

Diameter: 7.0 cm

Length: 31.75 cm

Weight: < 300 grams

Sensors: Pressure, Temperature, Humidity, Wind

Speed/Direction

Sensor Update Rate: 1 Hz

Wind data derived from Navigation GPS receiver

Telemetry via 400 MHz transmitter to Balloon

NCAR / ATD / SSSF

DROPONDE FALLVELOCITY AND TIME FOR A STANDARD ATMOSPHERE

DROPSONDE FALL TIME FOR 30 cm CHUTE

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FALL TIME - MINUTES

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DROPSONDE FALL VELOCITY FOR 30 cm POCKET CHUTE

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5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00

FALL VELOCITY - M/S

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NCAR / ATD / SSSF

Sonde PTH Sensors

Vaisala PTH OEM Module RSS903 (same sensor module used in Vaisala’s RS90 radiosonde):

Pressure Sensor Range: 100 mb to 1060 mb Resolution: 0.1mb Accuracy: ± 0.5 mb *

Temperature Sensor Range: -90° to +40° C Resolution: 0.1° Accuracy: ± 0.2° *

Humidity Sensor Range: 0% to 100% Resolution: 1% Accuracy: ± 2% *

* standard deviation of difference between two successive calibrations

NCAR / ATD / SSSF

Sonde Windfinding

GPS Receiver: Commercial OEM GPS Receiver

Receiver Specifications– Tracks up to 12 Satellites simultaneously– L1 frequency C/A only receiver – Horizontal Winds

Range: 0 to 150 m/s Resolution: 0.1 m/s Accuracy: ±0.5 m/s Position: 100 meters SEP with SA

NCAR / ATD / SSSF

Gondola Electronics

400 MHzReceiver

Single Board Computer

2-WaySatellite

Transceiver

GPS Receiver

Lithium BatteryPower Supply

Sonde &Balloon Ballast

Control Electronics

GPS Antenna

Satellite Antenna400 MHzAntenna

Transponder

Antenna

NCAR / ATD / SSSF

Gondola Electronics

Sonde/Ballast Controller

Single-Board Computer

PTH Buffer

400 MHz Telemetry Receiver

GPS Receiver

Lithium Batteries (10)

Card Chassis

Satellite Transceiver

NCAR / ATD / SSSF

ORBCOMM Satellite Coverage

NCAR / ATD / SSSF

Estimated Costs

Total costs per balloon deployment: 24 sondes @ $250 = $6,000

Balloon package: $3,000

Cost per sounding: $375

NCAR / ATD / SSSF

Example of sounding coverage fromDriftsondes deployed over Canada, Greenland & Iceland

Initial Launch Time: 00 UTC 30 Nov 1999 17 launch sites

Deployment Interval: 12hr

Drift Level: 45 mb

Coverage at: 18UTC 01Dec & 12UTC 02Dec 1999

Sea-Level Pressure

NCAR / ATD / SSSF

Example of sounding coverage fromDriftsondes deployed on the Asian Pacific rim

Initial Launch Time: 00 UTC 06 Feb 1999 13 launch sites

Deployment Interval: 12hr

Drift Level: 100 mb

300 mb Geopotential Ht

Coverage at: 18UTC 10Feb & 00UTC 11Feb 1999