Table of Contents

                                                                               Page (from 
                                                                               original report)
Foreword

1.   Introduction                                                                   1

2.   Ozone Measurement Principle and Theory                                         1
     2.1  Total Ozone Observations                                                  1
     2.2  Ozone Vertical Distribution (Umkehr) Observations                         4
     2.3  Principle of Operation of the Spectrophotometer                           4

3.   Calibration of a Dobson Spectrophotometer                                      6
     3.1  Relative Calibration                                                      6
          3.1.1     Adjustment of the Optics                                        7
          3.1.2     Q Calibration                                                   7
          3.1.3     Optical Wedge Calibration                                       7
     3.2  Absolute Calibration                                                      8
     3.3  Maintaining a Spectrophotometer in Calibration                            8

4.   Routine Spectrophotometer Tests and Maintenance                                9
     4.1  Purpose of Spectrophotometer Tests                                        9
     4.2  Frequency of Tests                                                        9
     4.3  Recording of Test Data                                                    9
     4.4  Test Procedures                                                           9
          4.4.1     Mercury Lamp Tests                                             11
          4.4.2     Standard Lamp Tests                                            12
          4.4.3     Wedge Calibration Tests                                        16
          4.4.4     Sensitivity Tests                                              18

5.   Instrument Maintenance and Repair                                             19
     5.1  Adjustment of Instrument Electronics                                     19
     5.2  Decrease in Shutter-Motor Speed                                          20
     5.3  Phase-Sensitive Signal Rectification                                     20
     5.4  Cleaning the Commutator                                                  21
     5.5  Radio-Frequency Pickup                                                   22
     5.6  Mechanical Shock Avoidance                                               23
     5.7  Instrument Temperature Control                                           23
     5.8  Renewing the Desiccant                                                   23
     5.9  Cleaning Optical Components                                              23
     5.10 Exposure of Photomultiplier to Intense Light                             24
     5.11 Replacing Standard Lamps                                                 24
     5.12 Replacing a Photomultiplier Tube                                         25

6.   Observations                                                                  27
     6.1  Observation Shelters                                                     27
     6.2  Observations of Total Ozone Amount                                       27
          6.2.1     Observation Types                                              27
          6.2.2     Times of Routine Ozone Measurements                            29
          6.2.3     Recording Observational Data                                   31
          6.2.4     Observing Methods                                              31
                    6.2.4.1   AD-DSGQP Observations                                33
                    6.2.4.2   AD-DSGQP* Observations                               36
                    6.2.4.3   CD-DSGQP Observations                                36
                    6.2.4.4   AD-ZB Observations                                   36
                    6.2.4.5   AD-ZC Observations                                   36
                    6.2.4.6   CD-ZB and CD-ZC Observations                         36
                    6.2.4.7   CC'-ZB and CC'-ZC Observations                       37
                    6.2.4.8   AD-DSFI and CD-DSFI Observations                     37
                    6.2.4.9   AD-RMFI and CD-RMFI Observations                     38
     6.3  Umkehr Observations                                                      38
          6.3.1     Observing Times                                                39
          6.3.2     Recording Observational Data                                   39
          6.3.3     Observing Procedures                                           39
     6.4  Special Observations                                                     42
          6.4.1     Observations Made to Check the Spectrophotometer
                    Calibration at A, C, and D Wavelengths                         42
          6.4.2     Observations Made to Correct Empirical Charts                  42
          6.4.3     Determination of Focused Image Corrections                     43
          6.4.4     Multiplying Factors Used in Reducing CDDSGQP 
                    Values to the ADDSGQP Level                                    43

7.   Reduction of Ozone Data                                                       44
     7.1  Calculations of Total Ozone from Measurements on Direct Sun or Moon      44
          7.1.1     Ozone Absorption Coefficients                                  45
          7.1.2     Rayleigh Scattering Coefficients                               47
          7.1.3     Particle Scattering Coefficients                               47
          7.1.4     Computation of mu                                              47
          7.1.5     Values of m and p/po                                           49
          7.1.6     Computation of Cos Z for Sun and Moon                          50
     7.2  Calculation of Ozone Amounts from Measurements on
          the Clear Zenith Sky                                                     50
          7.2.1     AD-ZB Observation                                              50
          7.2.2     CD-ZB Observations                                             52
          7.2.3     CC'-ZB Observations                                            52
     7.3  Calculation of Ozone Amounts from Measurements on
          the Cloudy Zenith Sky                                                    56
          7.3.1     AD-ZC Observations                                             56
          7.3.2     CD-ZC Observations                                             57
          7.3.3     CC'-ZC Observations                                            57
     7.4  Reduction of Umkehr Data                                                 57

8.   Coding and Archiving Ozone Data                                               59
     8.1  Coding Total Ozone Data for Publication                                  59
     8.2  Coding Umkehr Data for Processing and Publication                        59

References                                                                         64

Acknowledgements                                                                   65

Appendix A.     Determination of Q Setting Tables for Standard Wavelengths         66
Appendix B.     Correctingthe Table of Settings of Q                               73
Appendix C.     Calibration of the Dobson Spectrophotometer Optical Wedge          75
Appendix D.     Calibrating a Spectrophotometer on an Absolute Scale               85
Appendix E.     Determination of Corrections to N Tables
                from Standard Lamp Test Data                                       92
Appendix F.     Computation of Cos Z and, mu for Sun and Moon                      94
Appendix G.     Tables Used in Computing mu                                       108
Appendix H.     Introduction to Principles of Astronomy                           116
Appendix I.     Concept of Time                                                   122