Last Updated : May 29, 2007
www.ofcm.gov

Federal Meteorological Handbook No.3
Rawinsonde and Pibal Observations

FCM-H3-1997


Log of Changes - (List of pen and ink changes)  
  • Memorandum - Change No. 1 to the Federal Meteorological Handbook No. 3
    Effective August 1, 2006
PDF 1.6 MB
    • Replacement Page 6-2 listed in Change No. 1
PDF 74KB

Federal Meteorological Handbook No. 3 (FCM-H3-1997)
**This is the entire handbook with all changes incorporated.
 PDF 3.1 MB

FMH-3-1997 by chapter: (all changes incorporated)  

OPENING INFORMATION

  • Cover
  • Change and Review Log
  • Foreword
  • Table of Contents
  • List of Tables
  • List of Figures
 PDF 197KB

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

 PDF 102KB

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
 PDF 181KB

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
 PDF 150KB

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
 PDF 145KB

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
 PDF 153KB

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
 PDF 425KB

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
 PDF 120KB

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
 PDF 136KB

Appendix A: REFERENCES

 PDF 78KB

Appendix B: OBSERVATION SITE SPECIFICATIONS

 PDF 143KB

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

 PDF 62KB

Appendix D: COMPUTATIONAL FORMULAE AND CONSTANTS

 PDF 167KB

Appendix E: PILOT BALLOON AND RAWINSONDE ENCODING AND DECODING

 PDF 810KB

Appendix F: ARCHIVING

 PDF 146KB

Appendix G: GLOSSARY

 PDF 92KB