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

RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006 Microwave Bands Frequencies: Humidity Profiling: GHz Band (7 channels) LWP / IWV: 23.8 / GHz Temp. Profiling (Trop.): GHz Band (7 channels) Temp. Profiling (BL): GHz Band (4 channels) Spectral Bands of Operation: RPG-LWP RPG-HATPRO RPG-TEMPRO 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 Configuration

RPG Radiometer Physics GmbH 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 Temperature Sensor: Documentation of surface temperature Pressure 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 System removable dew 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 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 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 Layout Dual Profiler Direct Detection Filterbank Receivers based on MMIC Technology:

RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006 Synthesizer Emission from Heterodyne System Synthesizer emission from a heterodyne profiling 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 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 Design Splitter and Filter Section Boosters and Detectors Video Amps, MUX, 16 Bit ADC 55 dB Pre-Amplifier Noise Injection Coupler GHz 7 Channel Filterbank Receiver Corrugated Feedhorn

RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006 RPG-HATPRO Receiver Allan Variance Receivers obey radiometer formula: or: Tested up to: t int = 1000 sec 30 sec. Integr. Time → ∆T = 0.1 K

RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March GHz Brightness Temp. Noise in BL Mode 6 days time series of BL mode 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) 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, 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 Modes solid: boundary layer mode (4 channels) dotted: zenith mode (7 channels) dash-dotted: standard deviation of data set (360 samples) zenith mode zenith mode BL mode BL mode σ data

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

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

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

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

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

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

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

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

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

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

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

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

RPG Radiometer Physics GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006 Zenith 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 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 Profiling Comparison with radiosonde data. RMS Error: 0.5 g/m 3

RPG Radiometer Physics GmbH 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 GmbH µRAD 06 – San Juan, Puerto Rico, Feb./March 2006 Stability 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 thunderstorms likely KO -2

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