UK AIP co-ordinates conversion?

[obst lamp]

Hi,

Firstly, im not a pilot, im a broadcast network operator. However, I have a responsibility for ensuring navigation obstacles, specifically our radio masts and towers, are correctly lit and wherever the AWLs have failed, ensuring the details are on the latest NOTAM

To this end i have a query. One of our sites with failed warning lamps has proved a pig to identify on the AIP, neither ourselves nor NOTAM can work out which site it is. This has led me to notice that the location co-ordinates shown on the AIP for our sites are not in the format i'd expect, and no ammount of jiggery pokery seems to let me convert them.

As an example - Our Emley Moor TV mast, is, acording to AIP, located at 533643.50N 0013952.50W, whereas the co-ordinates i have are 53.61319 -1.66488. I can put my co-ordinates in any map/GPS etc and it shows the mast (im actually at Emley Moor and have checked on my GPS!)

I cant get any map or gps to accept the AIP format co-ords, neither can i find any way to convert them. (simply moving the decimal point to the other end put me in Lincolnshire [actually a few miles from the Belmont mast!])

Can anyone show me how to convert the co-ordinates on the AIP to something i can actually use on a GPS or map?

[Superpilot]

How much? :rolleyes:

[Superpilot]

Only kidding...

Our Emley Moor TV mast, is, acording to AIP, located at 533643.50N 0013952.50W, whereas the co-ordinates i have are 53.61319 -1.66488

533643.50N = 53 deg 36 min 43.5 seconds
0013952.50W = 001 deg 39 min 52.5 seconds

53 + (36/60) + (43.5/60/60) = 53 + 0.6 + 0.012083 = 53.612083
1 + (39/60) + (52.5/60/60) = 1 + 0.65 + 0.014583 = 1.664583

Answer 53.612083, -1.664583

https://maps.google.com/maps?q=53.612083,+-1.664583&hl=en&sll=53.612083,1.664583&sspn=18.487788,53.569336&t=h&z=16


DIY: Convert Latitude/Longitude to Decimal (http://andrew.hedges.name/experiments/convert_lat_long/)

:O

[Lightning Mate]

Scientific calculator set to degees function.

[chevvron]

All co-ordinates in the AIP are in WGS84 format, the internationally accepted standard, as it is based on the C of G of the planet as its datum. All GPS' show co-ordinates in this format too, so why obst lamp has been supplied with decimalised versions of this I can't understand.

[obst lamp]

Chaps, thankyou,

It all makes perfect sense now.

The decimalised degrees format (nn.nnnnnn) is how our site records have the location details, and the 'run together' nnnnn.nn format is how it shows on the AIP.

Oddly, the staff at NOTAM couldnt convert them either! And this particular mast was troublesome because we didnt know its obstruction ID number, and NOTAM didnt recognise it by its site name.

Now I can convert the formats, I can go through the AIP and our data and match the sites up. I'm also going to ensure that both us and NOTAM have accurate locations and obstacle ID numbers for all the masts.

Cheers
Martin

[Heathrow Harry]

Chevron wrote
"All co-ordinates in the AIP are in WGS84 format, the internationally accepted standard"

be very very careful in playing around with co-ordinates - the conversion from one system to another should be left to surveyors - just scaling something off one chart or map and putting it on another (or worse into an electronic device) can lead to really bad positioning errors