StarStruck Navigation
--John Masefield--
I have to agree with Al Placette when he said this is "one of the most beautiful and oft-quoted lines ever penned about sailing and the sea..."
If you have this extreme nostalgic feeling for this ancient art of navigation using the stars and the planets rather than a GPS, then this app is for you. This app is created with the hope that it could help to do a little part in preserving this beautiful art of navigation, and may be, bringing us all a little bit closer to those courageous sea goers centuries before us.
You can also use it for practical purposes of locating your position while trekking or navigating on the open sea. It is more fun to use than using a GPS and it doesn't drain your phone battery power as a GPS would.
Features
Highlighted functions:
1. This app allows you to enter sextant information of a star sighting and it calculates the most likely position for you.
2. The most likely position is shown on a map that you can zoom in and out to any location around the world.
3. It outputs the relevant information about any star that you are sighting (GHA, Declination, Intercept distance, Azimuth angle, calculated altitude, etc) for you to review. This is a handy feature so that you don't need to bother bringing those big and heavy Nautical Almanac volumes around with you.
4. It can make use of the sensor available on most smart phones to help you measure the altitude of a star by pointing your device in the direction of the star. This feature is handy when you don't have a sextant available.
5. It supports all the 57 navigation stars, plus the SUN, MOON, POLARIS and all the planets.
6. Other helpful aids: meridian, rise, set time and magnetic variation.
This software is a complement to your sextants. It is also a good tool to show your kids about astronomy and its practical benefit, that is how people have been using it to navigate their ways around the world.
Usage
To determine your position you must perform a series of star sighting (at least two but the more the better) and record the following information with the help of a sextant:
1. GMT time of the observations
2. Star name: SUN, MOON, Polaris, Sirius, Altair, etc.
3. Altitudes of the stars in degrees and minutes
4. Others info: eyes height above sea level, sextant correction index, lower or upper limb (required for the SUN and MOON only)
The app allows you to enter all these information and it calculates the most likely position for you.
Since most of us may not have a sextant, this app makes use of the available sensors on most smart phones to help you measure the altitude of the star by simply point the device to it. The sensor accuracy is within 1 degree so it is not as accurate as a good sextant but if you do several star sightings then the error will average out and you will get a good fix of your position.
Celestial Navigation Background
Rather than writing a complex mathematical tutorial on celestial navigation and perhaps turn away 90% of the users permanently, let me start by saying that celestial navigation is another way of determining your position on earth by using the stars as your light houses .
Please note that I am using the term star loosely here to mean the Sun, the Moon and the planets as well.
Most of us are familiar with the concept of the light house as it is a mean to help people at sea to determine their position and find their way to a safe port. By keeping track of light houses along your route on a map and follow them, one should be able to get to his destination without much trouble.
Similarly, this app is able to keep track of all the light houses in the sky and help you to navigate to your safe harbor
- even if your GPS is broken :)
Category : Tools
Reviews (27)
.8 nm from my actual position using a sextant for the first time!!
OUTSTANDING! First shot out of the box was within 50nm.
All you need & on uour phone!
Great app, probably the best ive found. Runs fine on my Samsung tablet. Used daily on voyage from Australia to China. Would be great if app had Lat / Long input from my tablets built in GPS.
Actually a great app but seems to be portrait only and not for landscape oriented devices. Hate it when switching between two apps where one is selectable to use landscape which i preffere but the other forces you to use portrait. However love the simplicity in the design. Only the info needed is shown and nothing more.
This is a great app. It makes astronavigation accessible to any one who wants to give it a try. You can even begin without a sextant. The corrections and calculations are handled behind the screen leaving a simple user interface. Put in the information on the form and it does the rest. Particularly. Handy is the "NOW" button to accurately grab the sight time. The app allows access to all the data allowing a deeper understanding when and if you are ready. I recommend this for both real navigation and as a great learning tool. The app has been updated to do all the calculations when practising at home using a bowl of water as an artificial horizon.
One of the best written Android apps out there. Highly useful. I am a former aircraft navigator who used a sextant professionally.
After I "Quit" the App, it won't restart, just hangs with a green band across the top of an otherwise blank screen. If I Force Stop it in App Manager, it will then start and run normally.
There appears to be an error it the Starstruck calculated altitude of the sights that I've used. For example: Date: Sept. 30, 2017, N47deg, W92deg, 19min. Moon: 23:32:30 UT, Starstruck calculated altitude is 15 deg 38 min, but the actual altitude should be 16deg 24min. Sun: 23:27:00 UT, Starstuck calculated altitude is 3deg 21min, but the actual altitude should be 3deg 07min. The actual calculated altitudes listed above have been verified with several other programs.
We use this app in teaching yachtmaster ocean course. It is very easy and accurate. It fills a gap between using the sextant accurately and position fix. It does the maths for you.
I have tested it at sea for 2 months and I am very impressed!
Nice to know if gps goes out. The satilites that is. Could happen in areas. Went to private nav school, and us coast guard school for 2 years . Also learned Space navigation as startreck. We used slide rules and many tables in many books..and all our fingers and toes to do the math. This course is fun.,easy,and how to do it without lots of books.and with them. SLIDE RULE NOT NEEDED.
Well designed app that is easy to use and has constant improvements. Well worth the money! A seafarer's must have app! Thank you so much for this :)
works flawless but when caounter checking with sample on pub.249 vol. 1 (epoch 2015), page v, introduction with star procyon, it showed too big difference with intercept distance although the azimuth is almost the accurate. On sample the result is Zn = 163*, intercept = 26 towards while in you program Zn = 162.64*, intercept = 45.5. Pls find below sample datas: DR: N54-17', E175-46' GMT: Jan 1, 2016, 12h 21m 25s Sextant read: 40*34' corr: -4' Please to hear your advise..
This apps are very usefull in daily basis. But it will become more helpfull and makes our life easier if the gyro error and meridian passage are included in this apps.keep up the good works.
Initially, there was a problem running on my device. The developer worked very hard to solve the problem. Now it works great. I especially like that it shows the likely position on the built-in world map. I give the highest ratings to the developer and this app!
Perfect, or almost perfect. The only option I'm missing is displaying Nautical Almanac data. But still this app is outstanding. And updated regularly, unlike some other apps. Clearly the winner.
Been navigating for 50 years, unlimited master deep sea. This is s fine tool!
The azimuth of stars isn't always fully displayed depending on the length of the star's name in the star map function. Please help. Thanks, Paul
Been into CelNav for a while. This app is way cool.
Either, I do not know how to use it or is there a problem. When I press LOCATOR is exiting. Nothing happen. I found this app very good, but not much of help explaining some functions.
Generally good, easy to use app. One glaring problem though is that the star map has azimuth increasing clockwise, which is the opposite of what I'm used to (when you're looking at the zenith, azimith increases CCW. Update to 4 stars: lots of improvements in the next version. No complaints. Would give 5 for general polish.
With my sextant, this is an excellent backup and replaces a standalone calculator which I used to use
On Samsung Galaxy Nexus OS ICS 4.0 it works well, and even using the 'phone as a sextant I got within 1 degree of actual position, useful as back up celestial calculator; great communication with developer. Note you can reverse CW or CCW star chart as you wish.
Now that it supports my timezone (+9.5) works well and it is very handy as backup for celestial calculator. Good for verifying stars you may not be sure of.
Wouldnt work on my samsung j1 :(
Very practical, easy to use