|     SAE J2735-Draft-Rev28 [issued: 11-10-08]   -  228 -  This is an SAE Motor Vehicle Council draft document of the DSRC committee, subject to change.  XML Representation:    <xs:simpleType name="Heading" >        <xs:annotation>           <xs:documentation>                     Vaild Encoding rules ,  an unsigned 8 bit value              0 = due north,  larger going clockwise  (east of north)              (0..253)  360/254 degrees per bit              254 = no heading at all  (stationary)              determined by              examining the velocity DE              255 = heading not known           </xs:documentation>        </xs:annotation>        <xs:restriction base="xs:unsignedByte"/>  </xs:simpleType>  Used By:  This entry is directly used by the following 4 other data structures in this standard (record type,  descriptive name, ASN.1, and XML name (if present) of each):  DF   <XML>, and  DF   <XML>, and  DF   <XML>, and  MSG   In addition, this item may be used by data structures in other ITS standards.  Formula:  Encode as an unsigned 8 bit value with 0 = due north, increasing going clockwise (east of north)  and (0..253) 360/254 degrees per bit.  Use values of 254 = no heading at all (stationary) and 255 = heading  not known.  Remarks:  No accuracy requirement known.  Note that magnetic north can vary from giod north  considerably and in the presence of local objects.  This element was originally defined in J2313.  From  Section 8.12 "Heading."  8.8 Data Element: DE_MAYDAY_Location_quality_code [ATIS]  Use:  A value representing the "goodness" of the position estimate (accuracy).  The element is used to  convey the relative quality of a GPS generated location.  This quality value is enumerated as shown, as  follows below.  ASN.1 Representation:    Location-quality ::= ENUMERATED {                               loc-qual-bt1m       (0), -- quality better than 1 meter       loc-qual-bt5m       (1), -- quality better than 5 meters       loc-qual-bt12m      (2), -- quality better than 12.5 meters       loc-qual-bt50m      (3), -- quality better than 50 meters       loc-qual-bt125m     (4), -- quality better than 125 meters       loc-qual-bt500m     (5), -- quality better than 500 meters       loc-qual-bt1250m    (6), -- quality better than 1250 meters       loc-qual-unknown    (7) -- quality value unknown       } -- 3 bits, appends with loc-tech to make one octet (0..7)  XML Representation:          <xs:annotation>           <xs:appinfo>              loc qual bt1m (0) -- quality better than 1 meter              loc qual bt5m (1) -- quality better than 5 meters              loc qual bt12m (2) -- quality better than 12.5 meters              loc qual bt50m (3) -- quality better than 50 meters              loc qual bt125m (4) -- quality better than 125 meters              loc qual bt500m (5) -- quality better than 500 meters              loc qual bt1250m (6) -- quality better than 1250 meters  |