| Introduction | p. 1 |
| Summary | p. 3 |
| The Radiometer Receiver. Sensitivity and Accuracy | p. 7 |
| What is a Radiometer Receiver? | p. 7 |
| The Sensitivity of the Radiometer | p. 8 |
| Absolute Accuracy | p. 9 |
| Radiometer Principles | p. 13 |
| The Total Power Radiometer (TPR) | p. 13 |
| The Dicke Radiometer (DR) | p. 14 |
| The Noise-Injection Radiometer (NIR) | p. 16 |
| Other Radiometer Types | p. 19 |
| Radiometer Receivers on Block Diagram Level | p. 21 |
| Receiver Principles | p. 21 |
| Direct or Superheterodyne | p. 21 |
| DSB - SSB with or without RF Preamplifier | p. 22 |
| Dicke Radiometer | p. 23 |
| Microwave Part | p. 23 |
| The Noise Figure and the Sensitivity of the Radiometer | p. 25 |
| The IF Circuitry and the Detector | p. 26 |
| The Extreme Signal Levels | p. 27 |
| The LF Circuitry | p. 28 |
| The Analog to Digital Converter | p. 30 |
| On the Sampling in the Radiometer. Aliasing | p. 34 |
| The Noise-Injection Radiometer | p. 35 |
| The Total Power Radiometer | p. 38 |
| Stability Considerations | p. 40 |
| Example: the Tud Noise-Injection Radiometers | p. 41 |
| Calibration | p. 49 |
| Why Calibrate? | p. 49 |
| Calibration Sources | p. 50 |
| Example: Calibration of the TUD 5 GHz Radiometer | p. 54 |
| Sensitivity and Accuracy of Different Radiometer Types | p. 57 |
| Background | p. 57 |
| The Radiometers Used in the Experiments | p. 58 |
| The Experimental Setup | p. 60 |
| 5 GHz Sensitivity Measurements | p. 60 |
| Stability Measurements | p. 62 |
| Discussion of the 5 GHz DR Results | p. 62 |
| The 5 GHz DR with Correction Algorithm | p. 65 |
| The 17 GHz NIR Results | p. 70 |
| Discussion of the TPR Results | p. 73 |
| Back-End Stability | p. 75 |
| Conclusions | p. 78 |
| Radiometer Antennas: Imaging Considerations | p. 81 |
| Beam Efficiency and Losses | p. 81 |
| Antenna Types | p. 83 |
| Imaging Considerations | p. 85 |
| The Dwell Time per Footprint versus the Sampling Time in the Radiometer | p. 90 |
| Receiver Considerations for Imagers | p. 95 |
| Relationships Between Swathwidth, Footprint, Integration Time, Sensitivity, Frequency, and Other Parameters for Satellite-Borne Imaging Systems | p. 97 |
| Mechanical Scan | p. 98 |
| Push-Broom Systems | p. 104 |
| Summary and Discussion | p. 105 |
| Examples | p. 106 |
| General Purpose Multifrequency Mission | p. 106 |
| Coastal Salinity Sensor | p. 108 |
| First Example of Spaceborne Imager: a Sea Salinity/Soil Moisture Push-Broom Radiometer System | p. 109 |
| Background | p. 109 |
| The Brightness Temperature of the Sea | p. 110 |
| The Brightness Temperature of Moist Soil | p. 111 |
| User Requirements for Geophysical and Spatial Resolution | p. 112 |
| Salinity Measurements | p. 112 |
| Soil Moisture Measurements | p. 112 |
| A 1.4 GHz Push-Broom Radiometer System | p. 113 |
| Sensitivity Considerations | p. 113 |
| Design of a 1.4 GHz Noise-Injection Radiometer Receiver | p. 113 |
| Antenna Considerations | p. 116 |
| Layout of the System | p. 117 |
| A 2.7 GHz Companion Radiometer System | p. 117 |
| Calibration | p. 119 |
| Disturbing Factors: Faraday Rotation, Space Radiation, Atmosphere | p. 121 |
| Faraday Rotation | p. 121 |
| Space Radiation | p. 123 |
| Atmospheric Effects | p. 124 |
| Summary | p. 124 |
| Second Example of Spaceborne Imager: "General Purpose" Mechanical Scanner | p. 127 |
| Background | p. 127 |
| System Considerations | p. 129 |
| Geometric and Radiometric Characteristics for MIMR | p. 129 |
| Preferred Instrument Options | p. 131 |
| Data Rate | p. 134 |
| Receiver Types and Calibration | p. 134 |
| Receiver Design | p. 135 |
| The Dual Receiver Concept | p. 135 |
| The Receivers | p. 139 |
| Physical Characteristics of the Receivers | p. 142 |
| Critical Design Features | p. 145 |
| Antenna Design | p. 146 |
| Calibration | p. 148 |
| Pre-Launch Radiometric Calibration | p. 148 |
| On-Board Calibration | p. 149 |
| Summary | p. 150 |
| References | p. 153 |
| Acronyms | p. 159 |
| Index | p. 161 |
| Table of Contents provided by Syndetics. All Rights Reserved. |
