Log4OM

Fixed the function to calculate distance with a AA11 format locator.

The "drawback" of this way is the locator distance is calculated from the BOTTOM LEFT point of the square. This is not an issue when working with 6 digits locators, but can become an issue when working with 4 digits locators (or 2 digits).
Also making a correction to use the center of the square can be an error itself...

Someone knows how awards calculate those distances? from locator box center? (i think no but...)

73
Daniele

IW3HMH wrote:Fixed the function to calculate distance with a AA11 format locator.

The "drawback" of this way is the locator distance is calculated from the BOTTOM LEFT point of the square. This is not an issue when working with 6 digits locators, but can become an issue when working with 4 digits locators (or 2 digits).
Also making a correction to use the center of the square can be an error itself...

Someone knows how awards calculate those distances? from locator box center? (i think no but...)

73
Daniele

From "INTERNATIONAL AMATEUR RADIO UNION REGION 1" (Vienna,May 2010) "VHF MANAGERS HANDBOOK"
cap 5.3.9
Scoring
For the amateur bands up to 10 GHz inclusive, points will be scored on the basis of one point per kilometre, i.e. the calculated distance in kilometres will be truncated to an integer value and 1 km will beadded.
The centre of each locator square is used for distance calculations.
In order to make contest scores comparable, for the conversion from degrees to kilometres a factor of 111.2 should be used when calculating distances with the aid of the spherical geometry equation (Noordwijkerhout, 1987)

in cap 5.13.3
.............
The difference between latitude/longitude on ED50 versus WGS84 is of the order of 300 meters.
This has no practical consequence to radio amateurs calculating their Maidenhead Locator
square other than the radio amateurs close to the square borders. Then it has consequence for
contest square multipliers.


So the "the distance between the logging station and the contacted station in kilometers" in ADIF.ORG defined as "a sequence of Digits optionally preceded by a minus sign (ASCII code 45) and optionally including a single decimal point (ASCII code 46)" is correct and in this case is referred to a positive INTEGER from 0 to half of circumference of the earth rounded as above.

Also in reverse calculation (grid to lat lon) is used the square center (eg. http://en.wikipedia.org/wiki/Maidenhead_Locator_System)

Other ideas ??

73 Sandro IW3RAB

Ok. Useful informations... need to fix the code

73