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SAE J2735-Draft-Rev18 [issued: 06-26-07]
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150 -
This is an SAE Motor Vehicle Council draft document of the DSRC committee, subject to change.
Typically, this vector is applied to stationary items, such as the location of an event, or to a moving location
where the relative offset distance and the heading vector with respect to the listener is most important. If
the position is not known, values of zero would be used in X,Y,Z. If the heading or speed is not known,
values of zero shall be used. Observe that the 32-bit values for Lat-Long provides a least significant bit (a
resolution) of approximately 4 inches in North America.
ASN.1 Representation:
SpaceVector ::= SEQUENCE {
lat DSRC.Latitude, -- a 4 byte value
long DSRC.Longitude, -- a 4 byte value
heading Heading, -- a 1 byte value from geoids north
speed Speed, -- a 2 byte field in units
-- of 0.01 meters per second
vertical DSRC.Elevation, -- 3 byte field
-- as a relative measure of merit
-- from [SAE-J2313::Location-tech]
-- from [SAE-J2313::Location-quality]
-- above two items form one 8 bit field
}
-- this element fits in exactly 15 bytes
XML Representation:
<xs:complexType name="SpaceVector" >
<xs:annotation>
<xs:documentation>
this element fits in exactly 15 bytes
</xs:documentation>
</xs:annotation>
<xs:sequence>
<xs:element name="lat" type="lrms:Latitude" />
<!-- a 4 byte value -->
<xs:element name="long" type="lrms:Longitude" />
<!-- a 4 byte value -->
<xs:element name="heading" type="Heading" />
<!-- a 1 byte value from geoids north -->
<xs:element name="speed" type="Speed" />
<!-- a 2 byte field in units
of 0.01 meters per second -->
<xs:element name="vertical" type="dsrc:Elevation" />
<!-- 3 byte field -->
<!-- how the position was obtained, acts
as a relative measure of merit
from [SAE-J2313::Location-tech] -->
<!-- estimate of accuracy for this location
from [SAE-J2313::Location-quality]
above two items form one 8 bit field -->
</xs:sequence>
</xs:complexType>
Used by: This entry is used directly by one other data structure in this standard, a MSG called
MSG_RoadSideAlert <ASN> <XML>. In addition, this item may be used by data structures in other
ITS standards.
Remarks: The definitions for Lat-Long etc. follow those defined and found elsewhere in the SAE J2735
work on DSRC message sets, which in turn are derived from the normal LRMS definitions.
8.10 Data Element: DE_HorizontalDatum:cd [LRMS]
Use: The underlying horizontal geodetic datum for a geographic coordinate.
ASN.1 Representation:
HorizontalDatum ::= ENUMERATED {wgs-84 (0),