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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)
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
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
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
HATPRO Instrument ConfigurationHATPRO Instrument Configuration
Scanningparaboloidmirror
ambienttemperaturetarget
beam combiner(wire grid) humidity profiler
temperature profiler
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
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
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
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 Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
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
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
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 Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
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
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
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
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
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.
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
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 Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
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
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
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
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
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)
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
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
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
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).
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
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
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
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) ..
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
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.
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
Boundary Layer Profiles ExamplesBoundary Layer Profiles Examples
RPG-HATPRO, DWD Lindenberg, Sept. 2005
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
Boundary Layer Profile ExamplesBoundary Layer Profile Examples
Benin, West Africa, January 2006 (AMMA)
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
Development and Decay of InversionsDevelopment and Decay of Inversions
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
Development and Decay of InversionsDevelopment and Decay of Inversions
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
Verification of BL MeasurementsVerification of BL Measurements
RPG-HATPRO at DWD Lindenberg, Sept. 2005
meteorologicaltower (99 m)
temp. sensorsevery 10 m
RPG-HATPRO
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
Direct Comparision at 10 / 100 m LevelsDirect Comparision at 10 / 100 m Levels
Mast
HATPRO
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
Direct Comparision at 10 / 100 m LevelsDirect Comparision at 10 / 100 m Levels
Mast
HATPRO
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
Direct Comparision at 10 / 100 m LevelsDirect Comparision at 10 / 100 m Levels
dry adiabatic lapse rate
mast
HA
TPR
OH
ATPR
OH
ATPR
O
mast
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
BL HATPRO/Radiosonde ComparisonBL HATPRO/Radiosonde Comparison
bias
RMS
Distance radiosonde launching site ↔ HATPRO: 4 km
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
BL Mode HATPRO/Radiosonde ComparisonBL Mode HATPRO/Radiosonde Comparison
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
Strong BL Temperature Inversions Strong BL Temperature Inversions
RPG-HATPRO at DWD Lindenberg, October 2005
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
BL HATPRO/Radiosonde ComparisonBL HATPRO/Radiosonde Comparison
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
Zenith Mode HATPRO/Radiosonde ComparisonZenith Mode HATPRO/Radiosonde Comparison
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
Zenith Mode HATPRO/Radiosonde ComparisonZenith Mode HATPRO/Radiosonde Comparison
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
Zenith Mode HATPRO/Radiosonde ComparisonZenith Mode HATPRO/Radiosonde Comparison
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
Zenith Mode HATPRO/Radiosonde ComparisonZenith Mode HATPRO/Radiosonde Comparison
bias
RMS
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
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
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
HATPRO Humidity ProfilingHATPRO Humidity Profiling
Comparison with radiosonde data. RMS Error: 0.5 g/m3
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
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)
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
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
RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006
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