RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006 Ground Based Tropospheric Profiling With the RPG- HATPRO 14 Channel Filterbank.

RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006

Ground Based Tropospheric Profiling With the RPG-Ground Based Tropospheric Profiling With the RPG-HATPRO 14 Channel Filterbank RadiometerHATPRO 14 Channel Filterbank Radiometer

Thomas Rose,Harald Czekala (Thomas Rose,Harald Czekala (Radiometer Physics GmbH)Radiometer Physics GmbH)


Microwave BandsMicrowave Bands

Frequencies:

Humidity Profiling: 22-31.4 GHz Band (7 channels)

LWP / IWV: 23.8 / 31.4 + 90 GHz

Temp. Profiling (Trop.): 50-59 GHz Band (7 channels)Temp. Profiling (BL): 54-59 GHz Band (4 channels)

Spectral Bands of Operation:

RPG-LWP

RPG-HATPRO

RPG-TEMPRO90

23.8 GHz

36.5/31.4 GHz

90 GHz

RPG-HUMPRO

RPG-TEMPRO

RPG-LWP-U90


HATPRO Instrument ConfigurationHATPRO Instrument Configuration

Scanningparaboloidmirror

ambienttemperaturetarget

beam combiner(wire grid) humidity profiler

temperature profiler


HATPRO Meteorological StationHATPRO Meteorological Station

Weather Station and Time Reference:

Rain Sensor: Provides rain flag for measurement documentation, control of super blower system

GPS-Clock: Provides time reference standard for synchronizationHumidity Sensor: Provides control of super blower system, documentationTemperature Sensor: Documentation of surface temperaturePressure Sensor: Documentation of baro-metric pressure, LN-target calibration

Humidity Sensor

Temp. Sensor Optional IR-Radiometer: Cloud base

height detection, ceilometer function


HATPRO Rain / Dew Protection SystemHATPRO Rain / Dew Protection System

removabledew blower Removal of dew

and rain by:

- strong blower system

System allows for temperature

profiling during rain


RPG-HATPRO Optical PerformanceRPG-HATPRO Optical Performance

23.8 GHz, HPBW = 3.9°, Sidelobes: <-30 dB 55.0 GHz, HPBW = 1.9°, Sidelobes: <-30 dB(6.5) (4.0)

humidity profiler temperature profiler


Thermal Receiver StabilisationThermal Receiver Stabilisation

Two stage thermal stabilisation system:

Receiver stabilisation:

<30 mK over full opera-ting temperature range (-30°C to + 45°C)


RPG-HATPRO Receiver LayoutRPG-HATPRO Receiver Layout

Dual Profiler Direct Detection Filterbank Receivers based on MMIC Technology:

Antenna

Directional Coupler

Pin-Switch

Noise Diode

Noise Injection

LNA

Splitter

DetBPF

Isolator

LNA

50-60 GHz Band

or22-32 GHz Band


Synthesizer Emission from Heterodyne SystemSynthesizer Emission from Heterodyne System

Synthesizer emission from a heterodyne profiling radiometer @ 26.4 GHz detected by RPG-HATPRO during radiometer

inter-comparison at DWD / Lindenberg, Germany, Sept./Oct. 2005


Synthesizer Emission from Heterodyne SystemSynthesizer Emission from Heterodyne System

Heterodyne system turned off: RFI disappears. ‘Passive’ radiometers are sometimes not fully passive but emit interference

signals in the RF bands.


Compact Receiver DesignCompact Receiver Design

Splitter and Filter Section

Boosters and Detectors

Video Amps,MUX, 16 Bit ADC

55 dB Pre-Amplifier

Noise InjectionCoupler

51- 59 GHz 7 ChannelFilterbank Receiver

Corrugated Feedhorn


RPG-HATPRO Receiver Allan VarianceRPG-HATPRO Receiver Allan Variance

Allan Variance (53.86 GHz)

-1.75

-1.5

-1.25

-1

-0.75

-0.5

-0.25

0 0.5 1 1.5 2 2.5 3

log(time [sec])

log

(va

ria

nc

e)

Receivers obeyradiometer formula:

Bt

TTT sigsys

int

or:

)log(5.0)log( inttT Tested up to:tint = 1000 sec

30 sec. Integr. Time→ ∆T = 0.1 K


58 GHz Brightness Temp. Noise in BL Mode58 GHz Brightness Temp. Noise in BL Mode

6 days time series of BL mode samples @ 58 GHz, 5° elevation (30 seconds integration time), RMS noise = 0.08 K


Two Scanning Modes (Temperature Profiling)Two Scanning Modes (Temperature Profiling)

2) Boundary Layer Mode: vertical Resolution: 50 m (<=1000 m)

System Requirements:- Elevation scanning: 5° - 90° requires narrow beamwidth (2° HPBW), leads to 250 mm eff. beam diameter- low noise channels- long integration periods- parallel acquisition of all channels- high receiver stability

1) Zenith Mode: vertical viewing direction, 51.26 - 58 GHz, 7 channels, used for full troposphere temperature profiles (<= 10 km)


RMS Errors of Both Observation ModesRMS Errors of Both Observation Modessolid: boundary layer mode (4 channels)dotted: zenith mode (7 channels)dash-dotted: standard deviation of data set (360 samples)

zenithmode

zenithmode

BLmode

BLmode

σdata


Full Trop. Temperature Profile in Zenith ModeFull Trop. Temperature Profile in Zenith Mode

Inversion

Full troposphere (zenith) scan. Inversion below 1km is not well resolved (about 1 K).


Same Inversion Measured in BL ModeSame Inversion Measured in BL Mode

A: Radiosonde (red) and boundary layer scan (blue) profiles at the same time as above. A strong ground inversion of 4K is resolved.

B: 6 hours later the inversion has disappeared (12:00).

6 hours later

A B


Boundary Layer Measured in Zenith ModeBoundary Layer Measured in Zenith Mode

Zenith observation mode. In the lower 500 m layer the Zenith observation mode. In the lower 500 m layer the vertical structure is not resolved in detail (Data taken from vertical structure is not resolved in detail (Data taken from

24. July to 28. July 2005 in Convective Storms Initiation 24. July to 28. July 2005 in Convective Storms Initiation Project, University of Salford / UK)Project, University of Salford / UK) ..


Boundary Layer Measured in BL ModeBoundary Layer Measured in BL Mode

Boundary layer scanning mode. The vertical structure even Boundary layer scanning mode. The vertical structure even in the lowest layer <100 m is clearly resolved.in the lowest layer <100 m is clearly resolved.


Boundary Layer Profiles ExamplesBoundary Layer Profiles Examples

RPG-HATPRO, DWD Lindenberg, Sept. 2005


Boundary Layer Profile ExamplesBoundary Layer Profile Examples

Benin, West Africa, January 2006 (AMMA)


Development and Decay of InversionsDevelopment and Decay of Inversions


Development and Decay of InversionsDevelopment and Decay of Inversions


Verification of BL MeasurementsVerification of BL Measurements

RPG-HATPRO at DWD Lindenberg, Sept. 2005

meteorologicaltower (99 m)

temp. sensorsevery 10 m

RPG-HATPRO


Direct Comparision at 10 / 100 m LevelsDirect Comparision at 10 / 100 m Levels

Mast

HATPRO



Mast

HATPRO



dry adiabatic lapse rate

mast

HA

TPR

OH

ATPR

OH

ATPR

O

mast


BL HATPRO/Radiosonde ComparisonBL HATPRO/Radiosonde Comparison

bias

RMS

Distance radiosonde launching site ↔ HATPRO: 4 km


BL Mode HATPRO/Radiosonde ComparisonBL Mode HATPRO/Radiosonde Comparison


Strong BL Temperature Inversions Strong BL Temperature Inversions

RPG-HATPRO at DWD Lindenberg, October 2005


BL HATPRO/Radiosonde ComparisonBL HATPRO/Radiosonde Comparison


Zenith Mode HATPRO/Radiosonde ComparisonZenith Mode HATPRO/Radiosonde Comparison







bias

RMS


HATPRO Humidity Profiling up to 10 kmHATPRO Humidity Profiling up to 10 km

Benin, West Africa, 19. January 2006 (AMMA)

45 kg/m^2

27 kg/m^2


HATPRO Humidity ProfilingHATPRO Humidity Profiling

Comparison with radiosonde data. RMS Error: 0.5 g/m3


LWP / IWV time seriesLWP / IWV time series

High temp. and spatial res. LWP time series for cloud analysis

temp. res.: 1 sec., abs. acc.: +/-20 g/m2 ,RMS Noise: +/- 2 g/m2

30 g/m2 (=0.03 mm)


Stability Indices RetrievalStability Indices Retrieval

Lifted Index, K-Index, Showalter Index, Total Totals Index, CAPE (derived from 7 oxygen line and 7 water vapour line channels)

TTI

KI

LI

50

30

thunderstorms likely thunderstorms likely

KO -2


SummarySummary

• Direct Detection Filterbank Design offers high Direct Detection Filterbank Design offers high temporal resolution, optimum radiometric noise temporal resolution, optimum radiometric noise performance and high stabilityperformance and high stability

• Low cost due to integrated receiver design and Low cost due to integrated receiver design and in-house fabrication of all RF componentsin-house fabrication of all RF components

• High temporal and spatial resolution for LWP High temporal and spatial resolution for LWP cloud observationscloud observations

• Superior performance of BL mode in the Superior performance of BL mode in the boundary layer has been demonstrated for boundary layer has been demonstrated for temperature profilingtemperature profiling

• Close to 100% duty cycle for all channelsClose to 100% duty cycle for all channels

RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006 Ground Based Tropospheric Profiling With the RPG- HATPRO 14 Channel Filterbank.

Documents

rpg hatpro

rpghumpro rpgtempro

san juan

puerto rico

rain sensor

rain slide

rpghatpro optical performance

sensor optional irradiometer