Ground Based Tropospheric Profiling With the RPGHATPRO 14

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Ground Based Tropospheric Profiling With the RPGHATPRO 14 Channel Filterbank Radiometer Thomas Rose, Harald Czekala (Radiometer Physics Gmb. H) RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

Microwave Bands Spectral Bands of Operation: Frequencies: RPG-TEMPRO Humidity Profiling: 22 -31. 4 GHz Band (7 channels) Temp. Profiling (Trop. ): 50 -59 GHz Band (7 channels) Temp. Profiling (BL): 54 -59 GHz Band (4 channels) LWP / IWV: / 31. 4 + 90 GHz RPG-TEMPRO 90 RPG-HATPRO RPG-HUMPRO RPG-LWP 90 GHz 23. 8 GHz 36. 5/31. 4 GHz RPG-LWP-U 90 23. 8 RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

HATPRO Instrument Configuration RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

HATPRO 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 synchronization Humidity Sensor: Provides control of super blower system, documentation Humidity Sensor Temperature Sensor: Documentation of surface temperature Temp. Sensor Pressure Sensor: Documentation of baro-metric pressure, LN-target calibration Optional IR-Radiometer: Cloud base height detection, ceilometer function RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

HATPRO Rain / Dew Protection System removable dew blower Removal of dew and rain by: - strong blower system System allows for temperature profiling during rain RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

RPG-HATPRO Optical Performance temperature profiler humidity profiler 23. 8 GHz, HPBW = 3. 9°, Sidelobes: <-30 d. B (6. 5) RPG Radiometer Physics Gmb. H 55. 0 GHz, HPBW = 1. 9°, Sidelobes: <-30 d. B (4. 0) µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

Thermal Receiver Stabilisation Two stage thermal stabilisation system: Receiver stabilisation: <30 m. K over full opera ting temperature range (-30°C to + 45°C) RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

RPG-HATPRO Receiver Layout Dual Profiler Direct Detection Filterbank Receivers based on MMIC Technology: RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

Synthesizer 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 Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

Synthesizer 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 Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

Compact Receiver Design 55 d. B Pre-Amplifier Splitter and Filter Section Boosters and Detectors Video Amps, MUX, 16 Bit ADC Noise Injection Coupler 51 - 59 GHz 7 Channel Filterbank Receiver RPG Radiometer Physics Gmb. H Corrugated Feedhorn µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

RPG-HATPRO Receiver Allan Variance Receivers obey radiometer formula: or: Tested up to: tint = 1000 sec 30 sec. Integr. Time → ∆T = 0. 1 K RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

58 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 Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

Two Scanning Modes (Temperature Profiling) 1) Zenith Mode: vertical viewing direction, 51. 26 - 58 GHz, 7 channels, used for full troposphere temperature profiles (<= 10 km) 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 RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

RMS Errors of Both Observation Modes solid: boundary layer mode (4 channels) dotted: zenith mode (7 channels) dash-dotted: standard deviation of data set (360 samples) zenith mode BL mode σ data RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

Full Trop. Temperature Profile in Zenith Mode Inversion Full troposphere (zenith) scan. Inversion below 1 km is not well resolved (about 1 K). RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

Same Inversion Measured in BL Mode 6 hours later A B A: Radiosonde (red) and boundary layer scan (blue) profiles at the same time as above. A strong ground inversion of 4 K is resolved. B: 6 hours later the inversion has disappeared (12: 00). RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

Boundary Layer Measured in Zenith Mode Zenith observation mode. In the lower 500 m layer the vertical structure is not resolved in detail (Data taken from 24. July to 28. July 2005 in Convective Storms Initiation Project, University of Salford / UK). RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

Boundary Layer Measured in BL Mode Boundary layer scanning mode. The vertical structure even in the lowest layer <100 m is clearly resolved. RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

Boundary Layer Profiles Examples RPG-HATPRO, DWD Lindenberg, Sept. 2005 RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

Boundary Layer Profile Examples Benin, West Africa, January 2006 (AMMA) RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

Development and Decay of Inversions RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

Verification of BL Measurements RPG-HATPRO at DWD Lindenberg, Sept. 2005 temp. sensors every 10 m meteorological tower (99 m) RPG-HATPRO RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

Direct Comparision at 10 / 100 m Levels Mast HATPRO RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

Direct Comparision at 10 / 100 m Levels HATPRO mast HATPRO dry adiabatic lapse rate RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

BL HATPRO/Radiosonde Comparison Distance radiosonde launching site ↔ HATPRO: 4 km bias RMS RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

BL Mode HATPRO/Radiosonde Comparison RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

Strong BL Temperature Inversions RPG-HATPRO at DWD Lindenberg, October 2005 RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

BL HATPRO/Radiosonde Comparison RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

Zenith Mode HATPRO/Radiosonde Comparison RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

Zenith Mode HATPRO/Radiosonde Comparison RMS bias RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

HATPRO Humidity Profiling up to 10 km Benin, West Africa, 19. January 2006 (AMMA) 45 kg/m^2 27 kg/m^2 RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

HATPRO Humidity Profiling Comparison with radiosonde data. RMS Error: 0. 5 g/m 3 RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

LWP / IWV time series High temp. and spatial res. LWP time series for cloud analysis temp. res. : 1 sec. , abs. acc. : +/-20 g/m 2 , RMS Noise: +/- 2 g/m 2 30 g/m 2 (=0. 03 mm) RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

Stability Indices Retrieval Lifted Index, K-Index, Showalter Index, Totals Index, CAPE (derived from 7 oxygen line and 7 water vapour line channels) thunderstorms likely 50 thunderstorms likely TTI 30 KI LI KO RPG Radiometer Physics Gmb. H -2 µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006

Summary • Direct Detection Filterbank Design offers high temporal resolution, optimum radiometric noise performance and high stability • Superior performance of BL mode in the boundary layer has been demonstrated for temperature profiling High temporal and spatial resolution for LWP cloud observations • • Close to 100% duty cycle for all channels • Low cost due to integrated receiver design and inhouse fabrication of all RF components RPG Radiometer Physics Gmb. H µRAD 06 – San Juan, Puerto Rico, Feb. /March 2006