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Coordinate formats advice please

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Old 11th May 2017, 13:08
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Coordinate formats advice please

Hi All,

Can anyone explain to me what coordinate format the following position is in please?

521404.50N 0010626.48E

It at first looks like decimal degrees but with the decimal point in the wrong place, however, that doesnt center on the actual location (ie if I just change it to 52.140450N 001.062648E its no where near the actual location in question)

The problem I have is that the position, which is a TV transmission tower, has been disputed by NATS! Clearly the tower (1200ft!) hasnt moved, and one or other of the records of the position is wrong. But my map systems will only work in decimal degrees nn.nnnnn etc, or deg,min,sec

Any help in making the conversion would be very much appreciated!
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Old 11th May 2017, 14:34
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Degrees, minutes, and seconds. For latitude: ddmmss.ss. For longitude: dddmmss.ss—that's three digits in degrees for longitude.

A position given to two decimal places in [arc] seconds is equivalent to ±15 centimetres north-south and ±9.5 centimetres east-west (at 52N), i.e. ±13 cm overall.

It is worth noting a relevant paragraph in the AIP:

5.4 Air Navigation Obstacles
5.4.1 List of Air Navigation Obstacles
5.4.1.1 The majority of air navigation obstacles listed in ENR 5.4 are solely identified by a combined Area Code and Reference Number e.g. UK0105A052F. The first four digits refer to the area in which the obstacle is sited and these areas are shown on the chart at ENR 6-5-4-1. These obstacles do not meet the accuracy requirements of original field work as specified in Annex 11, Chapter 2, and Annex 14, Volumes I and II, Chapter 2. Those obstacles identified additionally with an aerodrome ICAO identification code followed by the survey reference number are derived from aerodrome surveys and do meet the accuracy requirements of the original field work. The current Data Management Process does not provide assurance of the integrity of air navigation obstacles listed in ENR 5.4.
The aeronautical data quality requirements listed in appendix 5, table 1 (latitude and longitude), to Annex 11, establish standard accuracies of 50 metres for obstacles surveyed in the entire state, and 5 metres if they are part of an aerodrome or heliport boundary. Therefore you may safely ignore the decimal part of the arc seconds for obstacles of the first kind. The ICAO standard height accuracies, declared as not being met by UK, are 30 metres and 3 metres respectively (table 2).

Conversions done here:

Position Type Lat Lon
Degrees Lat Long 52.2345833°, 001.1073556°
Degrees Minutes 52°14.07500', 001°06.44133'
Degrees Minutes Seconds 52°14'04.5000", 001°06'26.4800"
UTM 31U 370755mE 5788817mN
UTM centimeter 31U 370755.03mE 5788817.53mN
MGRS 31UCT7075588817
Grid North -1.5°
GARS 363MW32
Maidenhead JO02NF26VH11
GEOREF NKBH06441407
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Old 11th May 2017, 15:01
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Ah! Wonderful! It never occurred to me to look at it as deg min sec but without the associated superscript symbols!

I knew it must be something obvious like that!

The difference in the co-ords I have for the site and those the ENR5.4 list looks to be a few dozen meters. I can now go back to my charts and find out which of us has the error!

Thanks
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