Radar Plotting vs Perpetual Nautical Almanac

Radar Plotting provides advanced radar-plotting capabilities for iPhone and iPad. Compute CPA/TCPA, estimate true motion, plan evasive/rescue/escape manoeuvres, and analyse two-target encounters — all visualised on an interactive radar sheet. Highlights: - Precise kinematic calculations (CPA/TCPA, aspect, true & relative speed) - Evasive manoeuvres with COLREG guidance - Rescue & escape planning, including scenarios with faster vessels - Double-target handling - Current/drift estimation - Interactive canvas with adjustable scales and animated trajectory playback - Import/export via QR code and PDF report generation Safety note: This app is for training and decision support. It does not replace certified navigational equipment or official procedures. Always follow COLREG and local/company rules.

Using the U.S. Naval Observatory NOVAS library and solar system ephemerides from JPL, high precision positions can be calculated in real-time from 1900 to 2050. Simply select date and time and all values are recalculated instantly. The estimated elevation value is only needed for calculating sunrise/sunset, twilight, and moonrise/moonset. The app provides the following functionalities: *Aries: GHA position *Sun: -GHA/dec - Astronomical dawn, nautical dawn, civil dawn, sunrise, sunset, civil dusk, nautical dusk, astronomical dusk, and meridian passage at Greenwich. - Semidiameter - Sunlight world map with the Sun and the Moon position. *Moon: - GHA/dec - Moonrise/moonset and meridian passage at Greenwich. - Semidiameter - Moon phase and age of the Moon. *Planets: - GHA/dec for Venus, Mars, Jupiter, and Saturn. *Stars: - Magnitude, SHA/dec of 99 stars ordered by SHA. *Corrections: - Correction for the atmospheric refraction. - Correction for the dip of the horizon. - Parallax correction for the Moon, the Sun, Venus, and Mars.