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Overview
Enables navigators to compute their position at sea using celestial navigation techniques.
Rise and set
- Calculates the times of rise, meridian passage, and set of the Sun, Moon, the navigational planets Venus, Mars, Jupiter, and Saturn, the 57 bright stars, Polaris and σ Octantis, taking into account all relevant corrections
- Calculates apparent altitude at meridian passage
- Calculates civil, nautical and astronomical twilight times
- Times given to the nearest minute and for any time zone
- Up to 31 days of times can be shown at once
- Takes into account the observer's height above the horizon
Find it
- Tabulates and plots the altitudes and azimuths of navigational bodies for a given date, time and location
- Includes corrections for standard refraction and parallax
- Highlights the best seven or best three stars for observations
- Three different plotting options are available
- Astronomical bodies are easily sorted into alphabetic, magnitude, altitude or azimuth order
Route planner
- Calculates the course and distance travelled, or the position, using rhumb line or great circle navigation
- Calculates how long it will take to get from the start position to your destination, or the speed required to reach the destination at a specified time
- Tabulates position of waypoints at equal intervals, together with their rhumb line distance, course, and the date and UT time
- Accounts for different time zones
- Plots routes on an interactive plot that includes coastal outlines
Sight reduction
- Determines a position (fix) from observations made with a sextant
- Allows the vessel to journey a variable course, which may be a rhumb line on the WGS84 spheroid
- Process of least squares finds the latitude and longitude that minimizes the intercepts of all the observations
- Input data easily checked using the 'Log' from which observations can be selected or deselected for use
- Includes a plot of position lines, fix, vessel course and confidence ellipse, along with coastal outlines
- Provides all the details of the calculations involved so they can be checked against those done by hand
- 'Find Next Phenomena' tool calculates the next sunrise, sunset or twilight based on position and course
- Data and results can be saved to and loaded from a file
Almanac
- Produces data similar to The Nautical Almanac (NP314), but without the need for interpolation
- Tabulates the Greenwich hour angle (GHA) and declination (DEC) for all navigational bodies and first point of Aries (the Vernal Equinox) to a precision of 0.1 arcminutes
- Tabulates the semi-diameter for the Sun, the horizontal parallax (HP) for Venus, Mars and the Moon, and the magnitudes of the stars and planets
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End-user Licence Agreement (EULA)
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End-user Licence Agreement (EULA)
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Please find the End-user Licence Agreement for the HMNAO NavPac below.
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Who to contact?
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Who to contact?
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In the first instance, please contact the distributor that you purchased NavPac from. If they are unable to help, contact the UKHO Customer Service team by email at customerservices@ukho.gov.uk or by phone: +44(0)1823 484444.