Category 63 support

Jeff Lawson — Fri, 21 Dec 2012 19:56:04 -0000

It seems that category 63 support does not yet exist. It is defined by the following PDF:

http://www.eurocontrol.int/sites/default/files/content/documents/nm/asterix/archives/asterix-cat063-spds-part10-v1.1-042005.pdf

Schema enhancement

Horst Dehmer — Sun, 10 Jun 2012 07:01:33 -0000

For data extraction/conversion it would be helpful to add some additional meta data to the XML specification schema.
Two's complement fields often define a scale (LSB) and a unit of measurement (UOM).

Examples
I062/070 (Time of Track): scale = 1/128, UOM = s
I062/100 (X/Y): scale/LSB = 0.5, UOM = m
I062/105 (latitude/longitude): scale/LSB = 180/2^25, UOM = degrees/°
I062/110/#4 (GNSS-derived Altitude): scale/LSB = 25, UOM = ft
I062/135 (Calculated Track Barometric Altitude): scale/LSB = 1/4, UOM = FL
062/185 (Vx/Vy): scale/LSB = 0.25, UOM = m/s

Adding such (optional) information, let's say to the format element, would greatly help data extraction/conversion.

Proposal
<dataitem id="I062/070" ...>
<field ...>
<format scale="1/128" uom="s">uint</format>
</field>
</dataitem>

For better readability (and higher accuracy) it probably would be advisable to not evaluate the scale and include it as is, i.e. 180/2^25 instead of 0,0000053644. A simple expression parser could evaluate the scales as needed at runtime.

If we could find some way or another to include these information, I'd happy to provide some patches (at least for cat. 62)

Recent changes to feature-requests

Category 63 support

Schema enhancement