Navigator software version 4.5 release note - august/04

Version 4.5 of the Navigator software has many new features. The user interface was redesigned, with support for Windows XP visual themes. It is also a service release, with the correction of a small error in the position of some stars ( check this text on the issue ).

Celestial Navigation

1. Changed the celnav form layout to better reflect the celestial navigation workflow.

With addition of new sextant correction options, I had to create a page dedicated to corrections. This was numbered page 1, because is the first thing you must set before entering the celestial observations.

Page 2 is for calculation of Line of Position (LOP). For each observation, input sight data and calculate the LOP. Save LOPs for position calculation.

Go to page 3 for astronomical position calculation, after all LOPs are calculated and saved.

2. Dip short correction - Use dip short to take sights in places where a sea horizon is not visible (ex: for land navigation). The far shore of a lake or river can be used as the horizon, using the dip short correction. Dip short is more convenient than the so called artificial horizon for training, if the suitable body of water is available.

Distance to the waterline must be at least 0.5 NM. Note that if the lake is large enough, due to the earth curvature the true water horizon will cover the opposite lake shoreline. In this case Navigator will automatically switch to the normal Dip formula.

3. A new (alternative) refraction formula dependent on pressure and temperature. It produces better results than the default formula if atmospheric conditions depart significantly from 20°C and 1010 milibars.

4. Included correction for parallax for planets. This is a small correction (<0.3') but is a step in the direction of more precise results that can be obtained with this version.

5. Sextant calibration table allows the application of an extra angle dependent correction to the sextant readings. This table is published by some sextant makers. It is not to be confused with the index error. In fact, the calibration should be 0´ for 0° angle. Multiple tables - for multiple sextants - can be maintained.

6. In addition to upper and lower limbs, the body center can now be used in Sun and Moon sights. This is useful when the sky is foggy and the Sun border is not clearly visible.

7. Correction of an issue in celestial position for stars. This affects the internal nautical almanac mostly for early dates but also has small impact in the current epoch. read more.

Chart Navigation

8. Added a drag tool (the hand button). Use it to drag the chart in the desktop.

>> Availability of the release

The release is available - and recommended - to all registered users from version 3.0 and up. You may apply for the upgrade in the following URL.

CD-ROM version of the upgrade is also available from the Author. In this case there is a US$10 charge for shipping & handling.


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Omar F. Reis - All rights reserved