 |
 |
 |
 |
|
 |
 |
SAE J2735-Draft-Rev15 [issued: 01-30-07]
-
112 -
This is an SAE Motor Vehicle Council draft document of the DSRC committee, subject to change.
ASN.1 Representation:
Heading ::= INTEGER (0..255)
-- 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
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 5 other data structures in this standard (record type, descriptive name,
ASN.1, and XML name (if present) of each):
DF
DF
DF
MSG
DF
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."
8.4 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)