1. T. Rose (RPG), H. Czekala (RPG),
Design of an Ultra-Stable 3 Frequency / Dual Pol. Radiometer for Remote Sensing of Rain
T. Rose (RPG), H. Czekala (RPG),
Soil Moisture Instrument
(BNU Beijing)
COPS Campaign
(Black Forest / Germany)

2. RPG’s Dual Polarized Radiometer Versions
6.925 / / 18.7 / 36.5 GHz
Soil Moisture Radiometer
10.65 / 21.0 / 36.5 GHz
Rain Observation Radiometer

3. Rain Observation Radiometer
RPG-6CH-DP
10.65 GHz:
high rain rates >30 mm/h
21.00 GHz:
med. rain rates >10 mm/h
36.5 GHz:
drizzle
Discrimination of cloud liquid and rain liquid water due to polarized emission from rain droplets

4. Dicke Switch / Noise Injection Calibration System
Modular Direct Detection Filterbank Design:
High long term stability due to full auto-calibrating front end
Parallel data aquisition of all channels

5. Waveguide DDFB Design
Full waveguide design guarantees high mechanical stability
Receiver Noise Temperature:
< 400 K
Auto-Calibration Devices:
Noise Injection
Magnetically switched Dicke SW

6. Y-Junction Isolator Dicke Switch Design

7. Y-Junction Isolator Dicke Switch for 90 GHz

8. RPG Waveguide Dicke Switches

9. Calibration Timing

10. Other Receiver Examples
90 / 150 GHz
full internal cal.
Insertion loss
90 GHz DS:
0.7 dB
Insertion Loss
150 GHz DS:
1.0 dB
Isolaton >30 dB

11. Calibration Test of Principle with 21 / 36.5 GHz System
12 Hours

12. Power Spectrum

13. Allan Variance up to 4000 Seconds

14. Thermal Receiver Stability
Hermetically insulated receivers
Thermal Stability <30 mK over full
operating temp. range (-30°C to +45 °C)
Dual stage thermal control system
Peltier stabilized receiver board
Low receiver power consumption < 3 Watts