Resolution MSC.115(73)
PERFORMANCE STANDARDS FOR SHIPBORNE COMBINED GPS/GLONASS RECEIVER EQUIPMENT,
REVISED IN 2000
(adopted
on 5 December 2000)
THE
MARITIME SAFETY COMMITTEE.
RECALLING
Article (28(b) of the Convention on the International Maritime Organization
concerning the functions of the Committee,
RECALLING
ALSO resolution A.886(21), by which the Assembly resolved that the function of
adopting performance standards and technical specifications, as well as
amendments thereto shall be performed by the Maritime Safety Committee and/or
the Marine Environment Protection Committee, as appropriate, on behalf of the
Organization,
RECALLING
FURTHER that, in accordance with resolution A.815(19) by which fee Assembly
adopted the IMO policy for the recognition and acceptance of suitable
radionavigation systems intended for international use to provide ships with
navigational position-fixing throughout their voyages, the Global Positioning
System (GPS) and the Global Navigation Satellite System (GLONASS) have been
recognized as possible components of the world-wide radionavigation system,
NOTING
that shipborne combined receiving equipment for the world-wide radionavigation
system offer improved availability, integrity, accuracy and resistance to
interference,
RECOGNIZING
the need to improve the previously adopted by resolution MSC.74(69). Annex 1
performance standards for shipborne combined GPS GLONASS receiver equipment in
order to ensure the operational reliability of such equipment and taking into
account the technological progress and experience gained,
HAVING
CONSIDERED the recommendation on the revision of resolution MSC.74(69), Annex 1
made by the Sub-Committee on Safety of Navigation at its forty-sixth session,
1.
ADOPTS the Recommendation on Performance Standards for Shipborne Combined
Receiver Equipment, revised in 2000 set out in the Annex to the present
resolution;
2.
RECOMMENDS Governments to ensure that combined GPS/GLONASS receiver equipment:
a) if installed on or after
1 July 2003, conform to performance standards not inferior to those specified
in the Annex to the present resolution; and
b) if installed before 1
July 2003, conform to performance standards not inferior to those specified in
Annex 1 to resolution MSC.74(69).
Annex.
RECOMMENDATION ON PERFORMANCE STANDARDS FOR SHIPBORNE COMBINED GPS/GLONASS
RECEIVER EQUIPMENT, REVISED IN 2000
1.1
The Global Positioning System (GPS) and Global Navigation Satellite System
(GLONASS) are space-based positioning, velocity and time systems. The GPS space
segment will normally be composed of 24 satellites in six orbits. The spacing
of satellites in orbit will be arranged so that a minimum of four satellites
will be in view to users world-wide, with a position dilution of precision (PDOP)
≤ 6. The GLONASS space segment will normally be composed of 24 satellites
placed in 3 orbital planes with 8 satellites in each plane. The spacing of
satellites in orbit will be arranged so that a minimum of four satellites will
be in view to users world-wide, with a PDOP ≤ 6.
1.2
A combined receiver, when compared to either the GPS or GLONASS receiver,
offers improved availability, integrity, accuracy and resistance to
interference; increased ease of installation, and the ability to operate in the
differential GPS mode (DGPS), differential GLONASS mode (DGLONASS) and combined
DGPS and DGLONASS mode, when available.
1.3
Receiver equipment capable of combining individual satellite measurements from
GPS and GLONASS constellations to form a single solution is intended for
navigational purposes on ships with maximum speeds not exceeding 70 knots. Such
equipment should, in addition to the general requirements contained in
resolution A.694(17), comply with the following minimum performance
requirements.
1.4
These standards cover the basic requirements of position-fixing for navigation
purposes only and do not cover other computational facilities which may be in
the equipment.
2. COMBINED GPS/GLONASS RECEIVER EQUIPMENT
2.1
The words combined GPS/GLONASS receiver equipment as used in these performance
standards include all the components and units necessary for the system to
properly perform its intended functions. The equipment should include the
following minimum facilities:
.1 antenna capable of
receiving both GPS and GLONASS signals;
.2 combined GPS/GLONASS
receiver and processor;
.3 means of accessing the
computed latitude/longitude position;
.4 data control and
interface; and
.5 position display.
2.2
The antenna design should be suitable for fitting at a position on the ship
which ensures a clear view of the satellite constellations.
3. PERFORMANCE STANDARDS FOR COMBINED
GPS/GLONASS RECEIVER EQUIPMENT
The
combined GPS/GLONASS receiver equipment should:
.1 be capable of receiving
and processing the Standard Positioning Service (SPS) signals of the GPS as
modified by Selective Availability (SA) and range code signals in GLONASS and
provide position information in latitude and longitude World Geodetic System
(WGS) 84 co-ordinates in degrees, minutes and thousandths of minutes. Means may
be provided to transform the computed position into data compatible with the
datum of the navigational chart in use. Where this facility exists, the display
and any data output should indicate that the co-ordinate convertion is being
performed and should identify the co-ordinate system in which the position is
expressed;
.2 operate on the L1
frequency signal and C/A code in GPS and L1 frequency signal and range code in
GLONASS;
.3 be provided with at least
one output from which position information can be supplied to other equipment.
The output of position information should be in accordance with the relevant
international standards*;
______________
* IEC 61162 Publication.
.4 have static accuracy such
that the position of the antenna is determined to within 35 m (95%) in
non-differential mode and 10 m (95%) in differential mode with horizontal
dilution of precision (HDOP) ≤ 4 or position dilution of precision (PDOP)
≤ 6;
.5 have dynamic accuracy
such that the position of the ship is determined to within 35 m (95%) in
non-differential mode and 10 m (95%) in differential mode with HDOP ≤ 4
or PDOP ≤ 6 under the conditions of sea states and ship's motion likely
to be experienced in ships*;
_________________
* Resolution A.694(17); IEC 6721-3-6, IEC 6945
and IEC 61108-3 Publications.
.6 be capable of selecting
automatically the appropriate satellite transmitted signals for determination
of the ship's position with the required accuracy and update rate;
.7 be capable of acquiring
satellite signals with input signals having carrier levels in the range of -130
dBm to -120 dBm. Once the satellite signals have been acquired the equipment
should continue to operate satisfactorily with satellite signals having carrier
levels down to -133 dBm;
.8 be capable of acquiring
position to the required accuracy, within 30 min, when there is no valid
almanac data;
.9 be capable of acquiring
position to the required accuracy, within 5 min, when there is valid almanac
data;
.10 be capable of re-acquiring
position to the required accuracy, within 5 min, when all GPS and GLONASS
signals are interrupted for a period of at least 24 h, but there is no loss of
power,
.11 be capable of
re-acquiring position to the required accuracy, within 2 min, when subjected to
a power interruption of 60 s;
.12 be capable of
re-acquiring an individual satellite signal and utilizing it in the position
solution within 10 s after being blocked for 30 s;
.13 generate and output to a
display and digital interface* a