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HATPRO Microwave Radiometer

JOYCE-TOPHAT ©B. Pospichal HATPRO-TOPHAT installed at Jülich

Principle

TOPHAT is a passive microwave radiometer manufactured by Radiometer Physics GmbH installed at the Forschungszentrum Jülich as part of JOYCE. It measures brightness temperatures at 7 channels along the slope of the water vapor absorption line at 22 GHz and at 7 channels along the slope of the oxygen absorption complex at 60 GHz with allow the retreival of integrated water vapor (IWV), cloud liquid water path (LWP) as well as tropospheric and humidity temperature profiles.

Zenith measurements alternate with rhi and ppi scans. Scan patterns are partially synchronized with the neighbouring cloud radar. Additionally, regular elevation scans within provide high-quality temperature profiles in the boundary layer. Attached to the side, it also includes two broadband infrared pyrometers, sensitive to water vapor, low-LWP (< 50 gm-2) liquid clouds as well as ice clouds.

Instruments

Instrument name current location Generation features
TOPHAT JOYCE G5 (upgraded from G2) azimut scanning, 2 IR radiometers
SUNHAT campaigns G1
FOGHAT campaigns G5 azimut scanning, 1 IR radiometer

JOYCE-TOPHAT ©B. Pospichal

Data

  • If you are interested in receiving data please contact: B. Pospichal

The figure shows the relative humidity (RH, top row) and temperature (second row) of the environment as well as the Integrated Water Vapor (IWV, third row) and Liquid Water Path (LWP, last row) derived from TOPHAT.

* RHUBC-II: quicklooks or quicklooks.

History

Period Place Project
22/07/2010 - today Forschungszentrum Jülich, Germany TR32
07/08/2009 - 24/10/2009 ARM AMF site , Cerro Toco, Chile 22°57'25.1"S,67°46'16.5"W RHUBC-II

Specifications

Parameter Specification
Receiver 1 (R1) water vapor and liquid water absorption
Frequencies (R1) [GHz] 22.24, 23.04, 23.84, 25.44, 26.24, 27.84, 31.40
Channel band-widths (R1) [MHz] 230, 230, 230, 230, 230, 230, 230
Optical Resolution (R1) (HPBW) 3.3°-3.7°
Temporal Resolution 1 to 2 seconds
Receiver 2 (R2) oxygen absorption
Frequencies (R2) [GHz] 51.26, 52.28, 53.86, 54.94, 56.66, 57.30, 58.00
Channel band-widths (R2)[MHz] 230, 230, 230, 230, 600, 1000, 2000
Optical Resolution (R2) (HPBW) 2.2°- 2.5°
Pointing Resolution (R2) 0.6° (elevation), 0.1° (azimuth)
Side-lobe level < -30 dBc
Infrared pyrometers 11.1 μm, 12.0 μm, accuracy 1.0 Kelvin
Size 630 mm x 360 mm x 900 mm
Power Consumption <120 W (350 W peak) + dew blower 130 W
Weight 60 kg
Manufacturer RPG

Instrument time-line 07/08/2009 - 24/10/2009 ARM AMF site , Cerro Toco, Chile, RHUBC-II campaign 22/07/2010 - today Forschungzentrum Jülich (JOYCE-JuCol) 2016 Upgrade to HATPRO-G5 receivers Available measurement modes · Vertically pointing observations with integration times up to 1 seconds. · Elevation scans for boundary-layer temperature profiles. · Full azimuth/elevation scanning capability for horizontal variability of water vapor and clouds JOYCE-CF Standard Operation Procedures · Standard measurement mode is vertically pointing, 1 second integration time · Every 15 minutes one elevation scan with following angles: 42°, 30°, 19°, 10.2°, 5.4° (duration ~100 seconds) · Every 30 minutes one azimuth scan at 30° elevation angle with 5° azimuth resolution (duration ~3 minutes)

· Automatic relative calibrations are routinely performed o automatic noise-switching for gain calibration with 50 Hz o System noise is calibrated every 5 minutes with view on ambient target · Absolute calibrations using LN2 are performed every 6 months Data quality assurance procedures · Automatic rain detection (data are flagged in case of rain detected by rain sensor) · Offset corrections for liquid water path · O-B statistics from atmospheric models for brightness temperature offset correction available · Spectral consistency checks · Thresholds for Level 2 data products · Housekeeping data analysis · Visual data inspection Available datasets The following data products are provided via the SAMD database. If you would like to have additional data or recent data that have not been uploaded to SAMD yet, please fill a data request sheet available at JOYCE-CF website.

Level 1 · Brightness temperatures (14 channels microwave) o Temporal resolution 1 second o 1 file per day (11-13 MB) o Filename: sups_joy_mwr00_l1_tb_v00_YYYYMMDDHHMMSS.nc

· Brightness temperatures (14 channels MW, 6 elevation angles) o Temporal resolution 15 minutes o 1 file per day (0.07 MB) o Filename: sups_joy_mwr00BL_l1_tb_v00_YYYYMMDDHHMMSS.nc

· Brightness temperature (2 channels infrared) o Temporal resolution 1 second o Filename: Level 2 · Integrated water vapor (IWV) o Temporal resolution 1 second o 1 file per day (3-4 MB) o Multivariate linear retrieval based on radiosoundings from De Bilt o Filename: sups_joy_mwr00_l2_prw_v00_YYYYMMDDHHMMSS.nc

· Integrated cloud liquid water (LWP) o Temporal resolution 1 second o 1 file per day (3-4 MB) o Multivariate linear retrieval based on radiosoundings from De Bilt o Filename: sups_joy_mwr00_l2_clwvi_v00_YYYYMMDDHHMMSS.nc

· Temperature profiles (from zenith pointing) o Temporal resolution: 1 second o 1 file per day (25-30 MB) o Multivariate linear retrieval based on radiosoundings from De Bilt o Filename: sups_joy_mwr00_l2_ta_v00_YYYYMMDDHHMMSS.nc

· Temperature profiles (from elevation scans for improved resolution in lowest 1000 m above ground) o Temporal resolution: 15 minutes o 1 file per day (0.04 MB) o Multivariate linear retrieval based on radiosoundings from De Bilt o Filename: sups_joy_mwrBL00_l2_ta_v00_YYYYMMDDHHMMSS.nc

· Humidity profiles o Temporal resolution 1 second o 1 file per day (25-30 MB) o Multivariate linear retrieval based on radiosoundings from De Bilt o Filename: sups_joy_mwr00_l2_hua_v00_YYYYMMDDHHMMSS.nc Composite products using data from TOPHAT · Cloudnet target classification uses LWP data from TOPHAT. Combined with cloud radar and ceilometer observation, clouds are characterized by their geometrical extent as well as their microphysical properties. · Data are available via ACTRIS cloudnet database http://cloudnet.fmi.fi

tophat.1593415654.txt.gz · Last modified: 2020/06/29 09:27 by bpospich