<p>Yes, it can be used, but it is not easy.</p>

<p>For the latitude, you usually need to know the Alt of Polaris. You can derive that if you know the Alt of two of the three, but the (spherical geometry) formulas for that are not simple.</p>

<p>For the longitude, you need Greenwich time and the RA of any star. Any star includes Vega, Altair and Deneb ;)</p>

CC BY-SA 3.0
2014-07-18T08:10:49.980Z
Well. So, how accurate the result be from above calculation, in comparison to GPS, if the altitude and RA of any star are accurately measured?
kaka
CC BY-SA 3.0
2014-07-18T12:52:17.583Z
@kaka Depends on how you're doing the above calculation. In general, the error effects from refraction/seeing etc will make it worse than GPS already. If you're going ultra-precise, well, carrying a GPS is easier.
Cheeku
CC BY-SA 3.0
2014-07-18T07:09:21.090Z
2014-07-18T07:09:21.090Z
Envite
<p>I am wondering, whether is it possible to use vega-altair-deneb asterism for navigational purpose? Or if there is any geometric relationship of it with Polaris?</p>

<p>Any idea. 
Thanks</p>

<navigation>
Can Summer Triangle asterism be used for navigation?
kaka
# Can Summer Triangle asterism be used for navigation?

(Asked by: username_0 on 2014-07-17)

I am wondering, whether is it possible to use vega-altair-deneb asterism for navigational purpose? Or if there is any geometric relationship of it with Polaris?

Any idea.
Thanks

**Tags:** navigation

---

## 1 answers

### Answer by username_1 on 2014-07-18. Score: 3 | Accepted answer

Yes, it can be used, but it is not easy.

For the latitude, you usually need to know the Alt of Polaris. You can derive that if you know the Alt of two of the three, but the (spherical geometry) formulas for that are not simple.

For the longitude, you need Greenwich time and the RA of any star. Any star includes Vega, Altair and Deneb ;)

> **Comments:**
> **username_0**: Well. So, how accurate the result be from above calculation, in comparison to GPS, if the altitude and RA of any star are accurately measured?  
> **username_2**: @kaka Depends on how you're doing the above calculation. In general, the error effects from refraction/seeing etc will make it worse than GPS already. If you're going ultra-precise, well, carrying a GPS is easier.  

---

