Sight reduction
Sight reduction Summary
Sight reduction is a mobile Android app in Maps And Navigation by Navigational Algorithms. Released in Jul 2014 (11 years ago). It has about 31.4K+ installs and 124 ratings with a 3.67★ (average) average. Based on AppGoblin estimates, it reaches roughly 1.3K monthly active users . Store metadata: updated Apr 25, 2025.
Recent activity: 12 installs this week (32 over 4 weeks) showing above average growth , and 1.00 new ratings this week View trends →
Store info: Last updated on Google Play on Apr 25, 2025 .
3.67★
Ratings: 124
Screenshots
App Description
Celestial navigation. Take the sextant and get your Line of Position.
Celestial navigation - Astronavigation
Sight reduction:
- Marcq Saint Hilaire Line of Position, intercept method (p=Ho-Hc, Zn)
- Input for observed altitude Ho or instrumental Hs (Nautical Almanac data needed for the Sun and the Moon)
- Calculator for Intercept method (p=Ho-Hc, Zn) altitude Hc and azimuth Zn
- Running fix
- Plots up to 3 Marcq Saint Hilaire Lines of Position on Google maps
- Local hour angle (LHA)
- List of navigational stars
- Logbook (output is copied to clipboard)
- New optimized user interface
- GNSS fix to check the solution
Sight reduction is the process of deriving from a sight the information needed for establishing a line of position.
This app is a calculator to get the intercept from the assumed position of the observer AP(latitude, longitude), the geographical position of the celestial body observed, GP(Dec, GHA), and its corrected altitude Ho.
Manual and examples in the developer's website.
Ref: https://en.wikipedia.org/wiki/Sight_reduction
User interface:
- Zoom buttons +/-
- Map types: standard, terrain, and satellite
- GPS location. ("Location" App permission must be allowed. Switch on you GPS, and then automatic location detection is possible)