Sight reduction icon

Sight reduction v4.12

Sight reduction screenshot 0 Sight reduction screenshot 1 Sight reduction screenshot 2 Sight reduction screenshot 3 Sight reduction screenshot 4 Sight reduction screenshot 5 Sight reduction screenshot 6 Sight reduction screenshot 7 Sight reduction screenshot 8 Sight reduction screenshot 9 Sight reduction screenshot 10 Sight reduction screenshot 11

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

Statistics

Google Play Rating History

Current
Average
Range

Rating Distribution

Total Ratings:

Downloads Over Time

Sight reduction has been downloaded times.

Total Downloads
Last 30 Days
Avg Daily Est.

Shaded area shows 30-day prediction based on historical trends

Historical data collection started recently. More data points will be available over time.

ApkTrusted Ratings & Reviews

0.0
0 ratings
5
0
4
0
3
0
2
0
1
0
✓ Thank you! Your review has been submitted and will be published after admin approval.
Be the first to write a review...

More from Navigational Algorithms

See more apps

Explore Tags

Browse all tags