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SAE J2735-Draft-Rev28 [issued: 11-10-08] 
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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:simpleType name="Location-quality" >
      <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