confused

[Russ]

why............GPS co ords.........150 37' 12.14 S 128 44' 09.96 E

 

but using ozrunway cursor it indicates S15.626 E128.745.........at the same location.

 

So............what am i missing here, apart from ........have tried "resetting" to another option within oz runway......not poss.

 

2ndly.......what is the better format...decimal degrees .... or ...degrees,mins,secs

 

 

[Guest Andys@coffs]

They are the same.....12.14seconds is 0.202333333 minutes (12.14sec/60sec) .....so 37.20233333333minutes /60 minutes is 0.620 degrees or pretty close to 150.620S......

 

Pretty much same place just different representation...as to which is best....I'd suggest go with the way your backup map displays so that in the event you have to transfer your logged location onto the paper system due failure your not fighting with a conversion you don't want to have to do....that said the aim here is to fly home from where you know yourself to be (within visual fix limits, not, as a requirement, to the nearest metre.....

 

in case all that wasn't clear first representation is degrees minutes and seconds, second is merely degrees down to 3 decimal place.......

 

We, as rec pilots, should be able to relatively easily convert from one to the other....no difference in converting decimal representation of hours (ie 3.142 hours) to hours minutes and seconds......

 

Andy

 

 

[Russ]

this lil old brown duck, just tried the "converting" thing, as you mentioned.......ok, i've just fried me brain matter. ( admittedly i'm challenged there )

 

 

[Guest Andys@coffs]

You could google degrees minutes seconds to decimal calculator....heaps of online options ...try this one http://www.satsig.net/degrees-minutes-seconds-calculator.htm

 

 

[Dieselten]

How much accuracy do you really need? It's pointless calculating to the fourth or fifth decimal place of a minute of arc when real world accuracy requirements are to within ten feet or so. Be pragmatic.

 

 

[Ada Elle]

In latitude, a second of arc is 100'; a thousandth of a degree is 111m. There's a factor of 3-4 difference. This might matter for bombing hospitals in afghanistan, for example.

 

 

[Dieselten]

I'll bear that in mind when I'm hanging the next load of Mk82s on the racks on the J160.

 

 

[Guest Andys@coffs]

see that's why I got the 230...Mk84's are much more forgiving of rounding up or down errors...

 

 

[River]

Love the black humour...

 

 

[Downunder]

Reviving a long dead thread.....beware!

The ozrunways co-ords are decimal it seems, written as 123° 45.6' (as a way point)

Should the minute figure be shown ( ' ) or is it actually not a decimal coordinate?

A bit confused.

It seems to be neither pure DMS or DD.....a hybrid?

[kgwilson]

There should be an option to display them in either digital format or deg,mm,ss. Pretty much any GPS can do this even the one on your phone.

[Downunder]

Android version....I'll look...

[facthunter]

There's advantages in either way. Latitude translates to a distance directly and Longitude is either arc to time direct or use trigonometry for the mid latitude track position. to factor it.. What you are used to is the general consideration for most. IF you are calculating I'd tend to the decimal option as simpler, but most of my time I've used degrees minutes and seconds.( The older way but I think it's more likely to produce an error using 60 rather than decimals ) Nev

[walrus]

......and I’m assuming WGS84, not AGD whatever for the datum.

 

From experience, you can overnavigate by fiddling around with this stuff. The surveys for almost all VFR charts predate GPS and you should be prepared for features to be up to a few miles out of position compared to GPS. So please continue to navigate, not just follow the magenta line.

 

‘Certified ’Airport positions should be accurate but don’t assume anything else is.