Dropsonde RICO Atmospheric Technology Division/ NCAR Terry Hock NCAR GPS Dropsonde Overview.

Dropsonde RICODropsonde RICOAtmospheric Technology Division/ Atmospheric Technology Division/

NCARNCARTerry HockTerry Hock

NCAR GPS Dropsonde NCAR GPS Dropsonde OverviewOverview

NCAR Dropsonde HistoryNCAR Dropsonde History

• NCAR developed the first dropsonde in the early NCAR developed the first dropsonde in the early 1970’s1970’s

• Added Omega Wind Finding mid 1970’s (ODW)Added Omega Wind Finding mid 1970’s (ODW)• Developed L2D2 (Lightweight LORAN Digital Developed L2D2 (Lightweight LORAN Digital

Dropsonde) in 1984Dropsonde) in 1984• Developed LOD2 (Light weight Omega Digital Developed LOD2 (Light weight Omega Digital

Dropsonde) 1986Dropsonde) 1986• Developed GPS Dropsonde 1996 for DLR, NOAA, Developed GPS Dropsonde 1996 for DLR, NOAA,

NCAR. NCAR. • Dropsonde Technology Licensed to Vaisala as RD-Dropsonde Technology Licensed to Vaisala as RD-

9292

Overview of DropsondeOverview of Dropsonde

• Measures (PTH)Measures (PTH)– PressurePressure– TemperatureTemperature– Humidity (2-sensors)Humidity (2-sensors)– Wind speed and direction (GPS receiver)Wind speed and direction (GPS receiver)

• Sensor sample rate 2Hz (both PTH and Sensor sample rate 2Hz (both PTH and GPS)GPS)

• Size: 2.75” Dia., 16” lengthSize: 2.75” Dia., 16” length

• Mass: 390 gramsMass: 390 grams

DropsondeDropsonde Components Components

• Codeless GPS receiverCodeless GPS receiver

• PTH Vaisala modulePTH Vaisala module

• 400 MHz telemetry 400 MHz telemetry transmittertransmitter

• HC11 8-bit HC11 8-bit MicroprocessorMicroprocessor

• Lithium battery packLithium battery pack

• Sondes are Sondes are manufactured by Vaisala manufactured by Vaisala inc, in Louisville, COinc, in Louisville, CO

(licensed through (licensed through UCAR)UCAR)

Temperature Humidity QCTemperature Humidity QC

Temperature Humidity QC & Temperature Humidity QC & rawraw

Wind Data QCWind Data QC

Wind Data QC and rawWind Data QC and raw

Dropsonde Fall VelocityDropsonde Fall Velocity

ER-2 Temperature ER-2 Temperature ProfileProfile

ER-2 Humidity ER-2 Humidity ProfileProfile

ER-2 Temperature & Humidity ER-2 Temperature & Humidity ProfileProfile

DLR Falcon U & V GPS DLR Falcon U & V GPS WindsWinds

Sonde Fall TimeSonde Fall Time

GPS DROPSONDE FALL TIME, 26 CM PARACHUTE

0

10000

20000

30000

40000

50000

60000

70000

80000

0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00 16.00 17.00 18.00

FALL TIME - MINUTES

AL

TIT

UD

E -

FE

ET

WITH CHUTE

Typical Fall Times10,000 ft. – 4.5 Minutes20,000 ft. – 8 minutes30,000 ft. – 10.5 Minutes

Aircraft Data SystemAircraft Data System

• 4- Channel Telemetry Chassis4- Channel Telemetry Chassis– 400 MHz Receivers400 MHz Receivers– GPS Proccessing CardGPS Proccessing Card– PTH BufferPTH Buffer– Sonde InterfaceSonde Interface

• Computer SystemComputer System– AVAPS Drop SoftwareAVAPS Drop Software– ASPEN Software (Post Processing QC, Temp ASPEN Software (Post Processing QC, Temp

Drop, Skew-T)Drop, Skew-T)

Aircraft Data SystemAircraft Data System

• 4 channel system 4 channel system allows for up to 4 allows for up to 4 sondes in the air sondes in the air simultaneouslysimultaneously

• Channel can be re-used Channel can be re-used typical within 4 minutes typical within 4 minutes of previous dropof previous drop

• System requires one System requires one operator, if rapid drops operator, if rapid drops are required two are required two operators may be operators may be necessarynecessary

RICO Dropsonde OverviewRICO Dropsonde Overview

• 280 Dropsondes280 Dropsondes

• NCAR C-130 AircraftNCAR C-130 Aircraft

• Standard 4 channel systemStandard 4 channel system

• ~ 12 Dropsonde released per flight~ 12 Dropsonde released per flight

• Dropsondes released over water east Dropsondes released over water east of Barbudaof Barbuda

RICO Dropsonde StaffingRICO Dropsonde Staffing• One ATD Operator in the field (Korn)One ATD Operator in the field (Korn)

– Dropsonde Operator for aircraft flightsDropsonde Operator for aircraft flights– Sonde inventorySonde inventory– Preliminary QC of the dataPreliminary QC of the data– Data archivalData archival– Interface with the P.I.’sInterface with the P.I.’s– Equipment maintenanceEquipment maintenance

• One operator can release dropsonde at a One operator can release dropsonde at a rate of one sonde every ~ 5 minutes, if rate of one sonde every ~ 5 minutes, if drops ar required more frequent than a drops ar required more frequent than a student assistant is required.student assistant is required.

Technical IssuesTechnical Issues

• Dropsonde GPS Receiver (Winds)Dropsonde GPS Receiver (Winds)– Aircraft P-Static (in high E-Fields)Aircraft P-Static (in high E-Fields)– Manufacturing ReliabilityManufacturing Reliability– RF Multi-pathRF Multi-path