Ground Based Tropospheric Profiling With the RPGHATPRO 14
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) RPG-TEMPRO 90 RPG-HATPRO RPG-HUMPRO RPG-LWP 90 GHz 23. 8 GHz 36. 5/31. 4 GHz RPG-LWP-U 90 LWP / IWV: 23. 8 / 31. 4 + 90 GHz 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 Temp. Sensor RPG Radiometer Physics Gmb. H Temperature Sensor: Documentation of surface temperature Pressure Sensor: Documentation of barometric pressure, LN-target calibration Optional IR-Radiometer: Cloud base height detection, ceilometer function 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 operating 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
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 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 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
- Slides: 40