• Memorandum - Change No. 1 to the Federal Meteorological Handbook No. 3
  Effective August 1, 2006

• Replacement Page 6-2 listed in Change No. 1

OPENING INFORMATION

• Cover
• Change and Review Log
• Foreword
• Table of Contents
• List of Tables
• List of Figures

Chapter 1: INTRODUCTION

• 1.1 Purpose and Scope
• 1.2 Relation to Other Handbooks and Manuals
• 1.3 Changes and Revisions
• 1.4 Agency Specific Procedures
• 1.5 Rawinsonde Program - General
• 1.6 History of U.S. Upper-air Observing Programs
• 1.7 Present Rawinsonde Program
  • 1.7.1 Network of U.S. Stations
  • 1.7.2 Network Design and Configuration
  • 1.7.3 Transmission of Observations
  • 1.7.4 Recording and Preserving Observations
  • 1.7.5 Data Applications

Chapter 2: SYSTEMS AND EQUIPMENT

• 2.1 Introduction
• 2.2 Accuracy and Precision of the Measurements
• 2.3 Flight Subsystem
  • 2.3.1 Balloons
  • 2.3.2 Flight-Train
  • 2.3.3 Radiosondes
• 2.4 The Surface Subsystem
  • 2.4.1 The Antenna
  • 2.4.2 The Receiver and Sensor Processing Units
• 2.5 The Data Processing Subsystem
  • 2.5.1 Recording Data
  • 2.5.2 Signal Processing
  • 2.5.3 Data File Formats
    

Chapter 3: PREFLIGHT PROCEDURES AND SUCCESS CRITERIA

• 3.1 Introduction
• 3.2 Safety Considerations
• 3.3 Flight Equipment Prerelease Actions
  • 3.3.1 Balloon Inflation and Performance
  • 3.3.2 Balloon Inflation
  • 3.3.3 Flight-Train Assembly
• 3.4 Preparing the Radiosonde for the Preflight Check
  • 3.4.1 Calibration of the Radiosonde Sensors
  • 3.4.2 The Surface Observation
  • 3.4.3 NAVAID Radiosonde
  • 3.4.4 Release Notifications
• 3.5 Notice to Airmen (NOTAM)
• 3.6 The Release
  • 3.6.1 Release into Thunderstorms
  • 3.6.2 Delayed Release
• 3.7 Termination of Radiosonde Observation
  • 3.7.1 Due to Missing Data
  • 3.7.2 Due to Weak Signal
  • 3.7.3 Other Reasons for Termination
• 3.8 Successful/Unsuccessful Observation Criteria
• 3.9 Multiple Releases
• 3.10 Unscheduled or Special Observations

Chapter 4: Quality Control at the Station

• 4.1 Introduction
• 4.2 Pressure Anomalies
  • 4.2.1 Anomalies Caused By Pressure Sensor or Radiosonde Failure
  • 4.2.2 Anomalies Caused By Balloon
  • 4.2.3 Anomalies Cased By Atmospheric Events
• 4.3 Temperature Anomalies
  • 4.3.1 Anomalies Caused By Temperature Sensor or Radiosonde Failure
  • 4.3.2 Superadiabatic Lapse Rates
• 4.4 Relative Humidity Anomalies
  • 4.4.1 Missing Relative Humidity Data
  • 4.4.2 Erroneous RH Data
  • 4.4.3 RH Data Biased Too High or Too Low
  • 4.4.4 Rapid Change in RH Immediately After Release
• 4.5 Wind Anomalies
  • 4.5.1 Anomalous Wind Data From Radio Direction Finding
  • 4.5.2 Anomalous Wind Data From NAVAID (LORAN or GPS) Systems
  • 4.5.3 Doubtful Wind Data
    

Chapter 5: PROCESSING SOUNDING DATA

• 5.1 Introduction
• 5.2 Level Selection - Thermodynamics Variables
  • 5.2.1 Standard Pressure Levels
  • 5.2.2 Mandatory Significant Levels
  • 5.2.3 Additional Level Selection
• 5.3 Wind Data
  • 5.3.1 Fixed Levels for Reporting Purposes
  • 5.3.2 Additional Winds
  • 5.3.3 Terminating Wind
  • 5.3.4 Maximum Winds
  • 5.3.5 Primary and Secondary Maximum Winds
  • 5.3.6 Wind Shear
  • 5.3.7 Mean Winds
  • 5.3.8 Other Factors
• 5.4 Selecting The Tropopause
  • 5.4.1 The First Tropopause
  • 5.4.2 Multiple Tropopause Levels
  • 5.4.3 Reporting
• 5.5 Coded Message Generation
• 5.6 Additional Information
  

Chapter 6: PILOT BALLOON OBSERVATIONS

• 6.1 Introduction
• 6.2 The Pibal Observation
• 6.3 Selecting the Site
• 6.4 The Theodolite
  • 6.4.1 Optical Features
  • 6.4.2 Angular Measurements
  • 6.4.3 Other Features
• 6.5 Theodolite Leveling and Orientation
• 6.6 Focusing the Theodolite
• 6.7 General Test
• 6.8 The Observation
  • 6.8.1 Release Time
  • 6.8.2 Theodolite Preparation
• 6.9 Balloons
• 6.10 Night Pibal Lighting Units
• 6.11 Train Assembly
• 6.12 The Release
• 6.13 Errors Encountered in Tracking the Balloon
  • 6.13.1 Extraneous Light
  • 6.13.2 Sun in Field
  • 6.13.3 Confusion of Stars with the Lighting Device
• 6.14 Termination
• 6.15 Preliminary Inspection of Data
• 6.16 Criteria for Satisfactory Observations
• 6.17 Pibal Evaluation
  • 6.17.1 Missing Data
  • 6.17.2 Errors
• 6.18 The Pibal Message
• 6.19 Theodolite Care and Adjustments
• 6.20 Storage Between Observations

Chapter 7: DATA DISSEMINATION

• 7.1 Introduction
• 7.2 Global, Regional, and National Telecommunications
  • 7.2.1 The Regional Telecommunications System
  • 7.2.2 National Telecommunications Systems
• 7.3 WMO Index Numbers
  • 7.3.1 Assignment of International Station Index Numbers
  • 7.3.2 Obtaining Assignments of WMO Block/Station Numbers
• 7.4 Transmitting Rawinsonde Reports
  • 7.4.1 RADAT
• 7.5 Data Archiving

Chapter 8: QUALITY ASSURANCE

• 8.1 Introduction
• 8.2 Monitoring and Quality Control
  • 8.2.1 Operational Quality Control
  • 8.2.2 Administrative Quality Control
  • 8.2.3 WMO Reports
• 8.3 Coordination and Quality Assurance
  • 8.3.1 The National and Regional Headquarters
  • 8.3.2 Exchange of Information Notifying Individual Upper-air Units
• 8.4 Documenting Quality Information for Archival Data

Appendix A: REFERENCES

Appendix B: OBSERVATION SITE SPECIFICATIONS

Appendix C: U.S. LAND-BASED RAWINSONDE STATIONS

Appendix D: COMPUTATIONAL FORMULAE AND CONSTANTS

Appendix E: PILOT BALLOON AND RAWINSONDE ENCODING AND DECODING

Appendix F: ARCHIVING

Appendix G: GLOSSARY