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NP303(1)/AP3270(1) Rapid Sight Reduction Tables for Navigation Volume 1 - Selected Stars - Epoch 2025
This volume contains the altitude to 1' and true azimuth to 1° for the seven stars most suitable for finding your position at sea with a sextant, for the complete range of latitudes and hour angles of Aries. This edition is valid for the period 2021-2029. This publication is aimed at the navigator using celestial navigation and provides the optimum selection of stars for a three-star fix.
| CONTENTS: | Page | |||||||
| Star Charts | ifc | |||||||
| 57 Navigational Stars | ii | |||||||
| Contents | v | |||||||
| Acknowledgements | vi | |||||||
| Foreword | vii | |||||||
| EXPLANATION | ||||||||
| 1. | Introduction | ix | ||||||
| 2. | The Altitude & Azimuth Tables for Selected Stars | ix | ||||||
| 3. | Auxiliary Tables, Star Charts and Plots | x | ||||||
| 3.1 | Star Charts | x | ||||||
| 3.2 | The Navigational Stars | x | ||||||
| 3.3 | Greenwich for Hour Angle of Aries | x | ||||||
| 3.4 | Correction for Preccession and Nutation | xi | ||||||
| 3.5 | Altitude Correction due to the Observer's Position | xi | ||||||
| 3.5.1 | Dip of the Horizon | xi | ||||||
| 3.5.2 | Refraction | xii | ||||||
| 3.6 | Altitude Correction due to Changes in Position | xii | ||||||
| 3.6.1 | Change in the Position of the Observer | xii | ||||||
| 3.6.2 | Change in the Position of the Body | xiii | ||||||
| 3.7 | Polaris Tables | xiii | ||||||
| 3.8 | Rapid Sight Reduction Form | xiii | ||||||
| 4. | Nomenclature and Terminology | xiv | ||||||
| 4.1 | Time Scales, UT, UTI and UTC | xv | ||||||
| 5. | Use of these Tables | xvi | ||||||
| 5.1.1 | Planning Sextant Observations | xvi | ||||||
| 5.1.2 | Example of Planning Observations | xvi | ||||||
| 5.2 | Finding Position from Sextant Observations | xvii | ||||||
| 5.2.1 | Sight Reduction Method | xviii | ||||||
| 5.2.2 | Reduction of a Single Observations | xix | ||||||
| 5.2.3 | A 3-Star Fix | xx | ||||||
| 5.2.4 | A 3-Star Fix with Movement of the Observer | xxii | ||||||
| 5.2.5 | Special Techniques for Rapid Reduction | xxiv | ||||||
| 5.3 | Method of Finding Latitude from Polaris | xxvi | ||||||
| TABULATIONS FOR SELECTED STARS, Epoch 2015.0 | 1 | |||||||
| SUXILIARY TABLES | ||||||||
| 1 | Altitude Correction for Change in Position of Observer | 321 | ||||||
| 2 | Altitude Correction for Change in Position Body | 322 | ||||||
| 3 | Conversation of Arc to Time | 323 | ||||||
| 4 | Greenwich Hour Angle of Aries for 2021-2029 | 324 | ||||||
| 5 | Correction for Precession and Nutation 2021-2029 | 326 | ||||||
| 6.7 | Correction Q for Palaris, Azimuth of Palaris | 329 | ||||||
| 8 |
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330 | ||||||
| 330 | ||||||||
| 331 | ||||||||
| AP3270 / NP303 Volume 1 ─ Rapid Sight Reduction Form ─ Example | 332 | |||||||
| AP3270 / NP303 Volume 1 ─ Rapid Sight Reduction Form | 333 | |||||||
| Related Publications | 334 | |||||||
| World Map of Time Zones | ibc | |||||||
