Sight reduction v4.12

Navigational Algorithms

About this app

Developer 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)

What's New

Upgraded to:
Android 16 - SDK 36
new Google Maps 'com.google.android.gms:play-services-maps:19.2.0'

Version Information

Version: 4.12
Downloads: 10K+
Updated on: Apr 25, 2025
Released: Jul 21, 2014
Requires: Android 5.0

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Sight reduction users say on Google Play

★★★★★

Ganesh Godhade

Nice app my request please update and more levels

★★★★

Darshan Meer. Chandani

It's a good game but I pass level 35 and no more level present in this game

★★★

Kim Ferguson

Absolutely love this game...problem it says there's more levels but, once you get to level 35 it just keeps repeating 😰😥😢

★★

Wilhelm Bohrer (Bill)

So many ads it's tough to say. It's def no fun with all the ads.

★

The Slayer

This may be a decent game but when the ads are 10x longer than the gameplay, that's an uninstall. Ridiculous that you can't play a level which takes 2 seconds without a 30 second ad. Just no.