Seconds or Decimal minutes?
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Seconds or Decimal minutes?
I used to work on systems which used the format DDMMSS. Increasingly I work on systems which use DDMM.MM. (Decimal minutes). The problem occurs when someone is given a position which does not indicate which format it is in and just gives a straight figure such as 584535N0123538E.
An example. I found a couple of techs filling a database with locations of UK airfields from an en-route supplement. I knew the system they were filling used DDMMSS but that the supp used DDMM.MM. They had not, yet, come across anything higher than 59 so did not know. They had to wipe the database and start again.
Similarily, someone was given a list of waypoints which had already been converted. Not knowing, and feeling knowledgable, they again "converted" them. At the end of the day everyone was so confused we had to scrap everything and ask for a virgin list.
Just wondering if anyone else has ever come across a similar problem, or if it is a problem in the civil world, or how prevalent it is?
[This message has been edited by ORAC (edited 03 September 2000).]
An example. I found a couple of techs filling a database with locations of UK airfields from an en-route supplement. I knew the system they were filling used DDMMSS but that the supp used DDMM.MM. They had not, yet, come across anything higher than 59 so did not know. They had to wipe the database and start again.
Similarily, someone was given a list of waypoints which had already been converted. Not knowing, and feeling knowledgable, they again "converted" them. At the end of the day everyone was so confused we had to scrap everything and ask for a virgin list.
Just wondering if anyone else has ever come across a similar problem, or if it is a problem in the civil world, or how prevalent it is?
[This message has been edited by ORAC (edited 03 September 2000).]
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It is a potentially disastrous problem. The ICAO format is DDMMSS N/S DDDMMSS E/W, and what is meant to be published. Of course, most RNAV systems use the DDMM.MM format which requires a conversion to be done between the formats. I used to do flight inspections for a number of the earlier GPS approaches, and the database integrity for the approach waypoints was always one of my major concerns. The regulatory information and technical requirements are still incompatible in many cases - be very, very careful!!
