TM-CSIN-10001 Intro to Cospas-Sarsat.pdf

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CAL-TM-CSIN-10001/D

INTRODUCTION TOCOSPAS-SARSAT

TRAINING GUIDE

EMS Technologies

(613) 727-1771 1725 Woodward Drive Issue Date

Fax (613) 727-1200 Ottawa, Ontario 2002-02-04

K2C 0P9



This document contains information that is proprietary and confidential to

EMS Technologies. This information may not be used, disclosed or copied,

in whole or in part, without the prior written permission of EMS

Technologies. 2002 EMS Technologies. All rights reserved.



EMS Technologies Introduction to COSPAS-SARSAT Course

Introduction to COSPAS-SARSAT Course

Course ObjectiveThe Introduction to COSPAS-SARSAT Course provides introductory knowledge

about the COSPAS-SARSAT system.

AudienceThis course is intended for any personnel working with the system.

Skills/Knowledge PrerequisitesNone.

Course Material The COSPAS-SARSAT Introduction Training Guide (CAL-TM-CSIN-10001) is

used.

Time Required One day is required.

Course OutlineThe course covers the following topics: (Course topics may be subject to

change.)Topics Page

• History of the COSPAS-SARSAT System 1

• A Technical Description of Beacons 10

• The Space Section of COSPAS - SARSAT 15

• A Technical Description of how the SAR System Works 31

• ATLUT Description 41

• GEOLUT Description 50

• OCC Description 55

• Typical Configurations 67

Training Equipment None.



EMS Technologies Introduction to COSPAS-SARSAT Course

Introduction to COSPAS-SARSAT Course

Day 1

Time Topic/Activity

8:30 - 9:00 History of the COSPAS-SARSAT System

9:00 - 10:00 A Technical Description of Beacons

10:00 - 10:15 Break

10:15 - 12:00 The Space Section of COSPAS - SARSAT

12:00 - 13:00 Lunch

13:00 - 14:15 A Technical Description of how the SAR System Works

14:15 - 15:00 ATLUT Description15:00 - 15:15 Break

15:15 - 15:45 GEOLUT Description

15:45 - 16:30 OCC Description

16:30 - 17:00 Typical Configurations

17:00 - 17:30 Question and Answer



COURSE: Introduction to COSPAS-SARSAT

TITLE: The History of the COSPAS-SARSAT System

PURPOSE: To familiarize the student with the history of the system.

Topics:

♦ COSPAS-SARSAT Definition

♦ COSPAS-SARSAT History

♦ Countries using EMS’s COSPAS-SARSAT Systems

♦ Basic Concepts of the COSPAS-SARSAT System

♦ Satellite Visibility Area of Existing COSPAS-SARSAT LUTs






COSPAS

Cosmicheskaya Sistyema Poiska Avariynich Sudov

(Space System for the Search of Vessels in Distress)

SARSAT

Search and Rescue Satellite Aided Tracking






COSPAS-SARSAT is an international satellite system

designed to assist search and rescue operations, using

distress beacons operating on 121.5, 243.0 or 406 MHz

and providing alert location data to Rescue Co-

ordination Centres.

Initially developed in 1979, the binding Memorandum

of Understanding was signed on October 5th, 1984. The

system was established and is operated by Canada,

France, Russia and the USA.

Operational use of COSPAS-SARSAT by SAR

agencies started on September 9th, 1982 with the crash

of a light aircraft in Canada, in which three people were

rescued. Since then, the system has been used for over a

thousand SAR events and has been responsible for the

saving of ten thousand lives worldwide.






EMS HAS DELIVERED SYSTEMS TO THE

MAJORITY OF COUNTRIES WITHIN THE

COSPAS - SARSAT COMMUNITY.

• AUSTRALIA 2 LEOLUTs, 1 OCC

• ARGENTINA 2 LUTs, 1 OCC, 1 GEOLUT• BRAZIL 3 LUTs, 1 OCC

• CANADA 4 LUTs, 3 GEOLUTS

• FRANCE 1 LUT

• HONG KONG 2 LUTs, 2 OCCs,

• INDONESIA 2 LUTs, 1 OCC, 1 RCC

• JAPAN 2 LUTs

• NEW ZEALAND 1 LUT, 1 GEOLUT

(monitored by Australia)

• PAKISTAN 1 LUT, 1 OCC

• PERU 1 LUT, 1 OCC, 2 RCCs

• SAUDI ARABIA 2 LUTs, 1 OCC, 2 RCCs

• SINGAPORE 2 LUTs, 3 OCCs

• SOUTH AFRICA 1 LUT, 1 OCC

• TAIWAN 2 LUTs, 1 OCC

• UNITED KINGDOM 1 LUT, 1 OCC, 1 GEOLUT

• UNITED STATES 4 LUTs






BASIC CONCEPT OF THE COSPAS-SARSAT SYSTEM






SATELLITE VISIBILITY AREA OF EXISTING

COSPAS-SARSAT LUTs

(Represents approximate System Land-Area Coverage at 121.5 MHz;

406 MHz covers the entire world due to 3-day memory on satellite)

dated 2000






LOCATIONS OF COMMISSIONED

COSPAS-SARSAT LEO LOCAL USER TERMINALS

(January 2002)

Alaska

Manaus

Callao

Churchill

Edmonton

California

Hawaii

Texas

Goose Bay

Puerto Rico

Recife

Brasilia

Santiago

Punta Arenas

Maspalomas

Tromsoe

Arkhangelsk

Moscow Novosibirsk

West Freugh

Toulouse

Bari

Ouargla

Beijing

Taejon

Nakhodka

Yokohama

KeelungLahore

Lucknow

Bangalore

Singapore

Hong Kong

Guam

Ambon

Jakarta

Albany

Bundaberg

Wellington

Parana

Cape Town

Rio Grande






LOCATIONS OF COMMISSIONED

COSPAS-SARSAT MISSION CONTROL CENTRES

(January 2002)

USMCC

PEMC

BRMCC

CHMCC

CMCC

SPMCC

NMCC

CMCUKMC

FMCC

ITMCC

ALMCC

CNMCC

JAMCC

TAMCCPAMCC

INMCC

SIMCC

HKMCC

IDMCC

AUMCC

KOMCC

ZSMCC

ARMCC






LOCATIONS OF OPERATIONAL

COSPAS-SARSAT GEO LOCAL USER TERMINALS

(January 2002)

Brasilia

Santiago

MoscowCombe Martin

Bangalore

Wellington

Ottawa

Maspalomas

Trenton (2)

Ezeiza




TITLE: The Technical Description of Beacons

PURPOSE: To familiarize the student with 121.5/243 and 406 MHz beacons.

Topics:

♦ Characteristics of a 121.5 MHz Beacon

♦ Sweep Period

♦ Characteristics of a 406 MHz Beacon

♦ Beacon Types






CHARACTERISTICS OF A 121.5 MHz BEACON

Parameter Value

RF Signal

Transmitted Power 50 - 100 mW PERP*

Transmission life 48 hours

Frequency 121.5 MHz ±6 kHz

Polarization Linear

Modulation

Sweep Rate 2 - 4 HzRange 300 - 1600 Hz (swept at least 700 Hz)

Modulation Type AM

Modulation Depth > 85%

Duty Cycle 40%

Sweep Period 250 - 500 msec

Confidence Factor 1 - 256

*Peak Effective Radiated Power relative to a 1/4 wavelength monopole mounted on a ground

plate.






DIAGRAM OF SWEEP PERIOD

Offset

Freq.

(Hertz)

Time (hundredths of a second)

The 121.5 MHz beacons were originally designed to be detected by radio

receivers in over flying airplanes. To make detection easier, the signal was

designed to produce a characteristic “beeping” pattern on an audio receiver.

This “beeping” is implemented by a repeating signal modulation which sweeps

across the frequency adjacent to the carrier, roughly 3 times per second. The

actual repeat interval is the sweep period (approx. 0.33 seconds).






CHARACTERISTICS OF A 406 MHz

BEACON

Parameter Value

RF Signal:

Carrier Frequency

Before January 1, 2002 406.025 ± 0.005 MHz

After January 1, 2002

Reference Beacons 406.022 ± 0.002 MHz

Beacons 406.028 ± 0.002 MHz

Power Output 5 W ± 2 dB

Digital Message

Repetition Period 50 seconds ± 5%

Digital Message• short message 112 bits (280 ms)

• long message 144 bits (360 ms)

Bit Rate 400 bps

Operating Temperature Range:

• Class 1 - 40°C to + 55°C

• Class 2 - 20°C to + 55°C

Thermal Shock 30°C temperature difference

Operating Life Time: At least 24 hours at minimum

Message Structure:

Synchronization Long/Short Msg

Message

Format

Country

Code

Number

Beacon

Identification

Code

Error

Correcting

Code

Other

data

Additional

Data

(Optional)

Extension Short Message






ELT - Emergency Locator Transmitters

• in widespread use in aircraft

• legislated specifications and carriage

• mostly 121.5/243 MHz

• eventually switching to 406 MHz

EPIRB - Emergency Position Indicating

Radio Beacons

• rapidly growing marine use

• legislated specifications and carriage

• mostly 406 MHz• 121.5 for pleasure boats

PLB - Personal Locator Beacons

• no clear legislation for land use

• 406 MHz only

Note: COSPAS/SARSAT plans to phase out 121.5 and 243 MHz

beacons by 2009.




TITLE: The Space Section of COSPAS-SARSAT

PURPOSE: To introduce functions and capabilities of COSPAS-SARSAT satellites.

Topics:

♦ Description of Satellite Orbits

♦ Earth Fixed Co-ordinates

♦ Classic Keplarian Co-ordinate System

♦ System Block Diagram

♦ Space Segment SAR Instrument Status






DESCRIPTION OF SATELLITE ORBITS







One polar orbiting satellite scans the entire globe every 12 Hours.







12:00 UTC 1:45 UTC

3:30 UTC 4:15 UTC

Satellites appear to move West due to the Earth’s Rotation.






EARTH FIXED CO-ORDINATES

Greenwich

Meridian

Equator

These are defined relative to the Earth and rotate with the earth. Three position

coordinates, three velocity coordinates, and a time coordinate (Epoch) comprise

this co-ordinate system.






CLASSICAL KEPLERIAN CO-ORDINATE SYSTEM

Apogee

Greenwich

Meridian Inclination

Equator Longitude of the Ascending Node

Perigee Apogee

Argument of

Perigee

Satellite

Perigee True Anomaly

(Continued ...)






CLASSICAL KEPLERIAN

CO-ORDINATE SYSTEM (2)

The Classical Keplerian Co-ordinate system is described by six geometric

coordinates and one time coordinate.

The geometric coordinates are:

• The semi-major axis: one half the distance between the perigee (closest

point to Earth) and the apogee (furthest point from Earth).

• The eccentricity of the orbit: the distance from the centre of the earth to

the centre of the major axis, divided by the major axis length.

• The inclination: the angle measured from the plane of the equator to the

plane of the satellite orbit.

The sense of the angle is such that an inclination of zero degrees indicates

an orbit about the equator in the same direction as the earth’s rotation; an

inclination of 90 degrees indicates a polar orbit, and an inclination of 180

degrees indicates an orbit in which a satellite moves in a direction

opposite to the rotation of earth.

• The longitude of the ascending node: the angle from the Greenwich

meridian to the point where the satellite path crosses the equator when thesatellite is moving in an upward (Northerly) direction (ascending node).

• The argument of the perigee: the angle, measured in the direction of

satellite travel, from the ascending node to the perigee.

• The true anomaly: the angle from the perigee to the satellite, measured in

the direction of satellite travel.








SYSTEM BLOCK DIAGRAM

SPACECRAFT

121.5 MHz

406 MHz

121.5 MHz

Receiver

406 MHz

Receiver

1544 MHz

XMIT

406 MHz

RCVR/PROC

1544 MHz

RCVR

Satellite

Memory

406 MHz

PDS Processor

406 MHz

G-SARP Processor

121.5 MHz

Processor

Communications Interface

MCCOther

MCCs

RCCs/

SPOCs

RADIOBEACON

SEGMENTSPACE SEGMENT GROUND SEGMENT SAR NETWORK

BEACONS LOCAL USER TERMINAL

MISSION CONTROL

CENTRE






LEOSAR SPACECRAFT

INSTRUMENTATION

Receiver•

•

•

•

Receives beacon data at 121.5 MHz, 243.0 MHz, and 406.0 MHz

SARPSearch and Rescue Processor : the instrument on LEOSAR satellites that

receives, processes, and stores 406 MHz beacon signals.

SARR Search and Rescue Repeater : the instrument on LEOSAR satellites that

receives and modulates 121.5, 243, and 406 MHz signals.

TransmitterTransmits downlink data with 121.5 MHZ, 243.0 MHz, 406.0 MHZ

repeater signals, and 406 MHZ Processed Data Stream (PDS) data.






PAYLOAD AND INTERFACE DIAGRAM FOR SATELLITE

SARP

- repeated beacon data

(local mode)- 2.4 kbps PDS from SARP






SEARCH AND RESCUE PROCESSOR

(SARP)Available for 406 MHz data only

SARP Designations:

In increasing order of performance: SARP-0, SARP-M, SARP-1, SARP-2,

SARP-3.

Relative to SARP-1, SARP-2 has improved capacity, bandwidth, and protection

against 406 MHz interferers. SARP-3 is similar to SARP-2, with the additional

ability to provide the Serial Number of 406 MHz beacons, and to provide on-

demand downloading of housekeeping data (for French ground-segment only.)

Availability:

COSPAS: SARP-1 or SARP-2

SARSAT: SARP-1, SARP-2, or SARP-3

Memory Capacity :

COSPAS SARSAT

Messages 2048 2048(short) 1820 (long)SARP-1

Bits 327680 ~ 300 k

Messages 2688 2048SARP-2

Bits 524288 ~ 400k

Messages — 20281

SARP-3Bits — ~400k

1Can be increased to 2560 on command from the payload supplier.

Real-Time and Memory

“Real-time” is within about 15 seconds.•

•

•

•

If Memory is ON, data is stored and transmitted in real-time.

If Memory is OFF, data is transmitted in real-time only

The duration for which messages can be stored depends on the level of beacon

activity.






SEARCH AND RESCUE REPEATER (SARR)

COSPAS: 121.5 MHz only•

• SARSAT: 121.5, 243.0, and 406.0 MHz

Bent-Pipe:

Another term for the repeater mode of operation. The SARR operates like a

bent pipe in that received beacon data are immediately retransmitted to any

LUT that is located in the satellite footprint at the time of transmission.

LUT Processing:

Constant Bin Correlation (CBC)

processing is done on 121.5 MHz, 243.0 MHz, and 406 MHz data that are

relayed to the LUT by the SAR Repeater.

G_SARP406 MHz beacon signals received from the SARR do not have time and

frequency information. Therefore, LEOLUTs (i.e., those receiving data

from Low Earth Orbit satellites) have to determine time and frequency for

the 406 MHz SARR channel. This part of the instrumentation and software

is called the Ground-Search and Rescue Processor (G-SARP).






SPACE SEGMENT LEO SAR

INSTRUMENT STATUS(As of 24 January, 2002)

COSPAS -

SARSAT

406 MHz SARP 121.5

MHz

243.0

MHz

406 MHz

REPEATER

PAYLOAD Global Mode Local Mode SARR SARR

COSPAS – 41(C4) Limited Limited Limited N/A N/A

COSPAS – 9 (C9) Active Active Active N/A N/A

SARSAT – 4 (S4) Active Active Active Active N/O

SARSAT – 6 (S6) N/O N/O Active Active Active

SARSAT – 72(S7) Active Active Active Limited Active

SARSAT – 82(S8) Active Active Active Limited Active

N/A - NOT APPLICABLE

N/O - NOT OPERATIONAL

L - LIMITED

1 Not in continuous operation due to battery limitations

2Intermittent loss of service that may affect an entire or partial satellite pass.






GEOSAR SATELLITE COVERAGE

(January 2002)






SPACE SEGMENT GEO SAR

INSTRUMENT STATUS

Satellite Location Status GEOLUTs

GOES – W (USA) 135 W In operation Trenton (Canada)

GOES – E (USA) 75 W In operation Trenton (Canada),

Santiago (Chile),Maspalomas (Spain),

West Freugh (UK)

INSAT – 2B (India) 93.5 E Limited1

Bangalore (India)

1Intermittent gaps in coverage




TITLE: A technical description of how the SAR system works

PURPOSE: To familiarize the student with the SAR system.

Topics:

♦ COSPAS-SARSAT Typical System Performance

♦ Detection Geometry

♦ Principle of Operation of COSPAS-SARSAT LEOSAR System

♦ Doppler Principle

♦ CTA and TCA

♦ Satellite Beacon Geometry

♦ Doppler Location Processing






COSPAS-SARSAT TYPICAL SYSTEM

PERFORMANCE

DETECTION OF BEACON

• Beacon and LUT must see satellite. This is known as

Mutual Visibility.

• Mutual Visibility is not necessary for PDS Global Data

relayed through satellite memory.

AVERAGE WAIT TIME - GEOSAR

• Less than five minutes.

AVERAGE WAIT TIME - LEOSAR

• Depends on latitude and active satellites.

• Approximately 3 hours at the equator and 1 hour close to

the poles.

• Coverage is centred around the LUT.

POSITION ACCURACY

• 121.5/243 MHz beacons 10 - 20 km

• 406 MHz beacons 1 - 5 km






COSPAS Satellites orbi

an altitude of ~1000 km

whereas SARSAT

satellites orbit at ~ 850 k

altitude.

Satellites have a

velocity of ~ 7 km/s.

LOCAL USER

TERMINAL (LUT

EMERGENCY

BEACON(S)

DETECTION GEOMETRY






• Beacon transmits omni-

directional signal from

ground.

• Orbiting satellite receiv

signal.• Satellite motion creates

Doppler shift in beacon

carrier frequency.

• 121.5/243 MHz signals

are relayed for ground

processing.

• 406 MHz signals are

partially processed insatellite.

• Doppler shift used for

position calculation

PRINCIPLE OF OPERATION OFCOSPAS-SARSAT LEOSAR SYSTEM






DOPPLER PRINCIPLE

• Satellite motion creates Doppler shift in beacon

carrier frequency as relayed to the ground;

• Ground station (LEOLUT) measures Doppler shift of

carrier;

• Point of inflection is the time of closest approach

(TCA) between beacon and satellite (see next page);

• Magnitude of Doppler shift provides a cross track

angle (CTA) path;

• With the known satellite orbit data, the TCA and

CTA, the LEOLUT can calculate beacon locations;

• Left/right ambiguity is resolved by:

• operational knowledge

• signal processing using earth rotation

• second pass and solution merge






SATELLIT

F

R

E

Q

UE

N

C

Y

TIME

A - Satellite receives the frequency of the beacon. Because the

satellite is traveling at 7 km/s, there is a Doppler shift in the

received frequency.

B - Satellite is above the beacon, either directly or adjacent.

The received frequency equals the transmitter’s frequency.

C - As the satellite travels away from the transmitting beacon,

the received frequency decreases.






Actual

Frequency

of the ELT

transmitter.

TCA - Time of Closest Approach. The

time at which the satellite is closest to the

beacon during a satellite pass.

CTA - Cross Track

Angle. Determined

the magnitude of

frequency change.

Time

Frequency

LOS - Loss of Signal

from Satellite. AOS - Acquisition of

Signal from Satellite.

CTA and TCA(Cross Track Angle and Time of Closest Approach)

Must have minimum of 5 minutes in a satellite pass in order for the

ATLUT to recognize and process a Doppler Curve.






B A

SATELLITE

POSITIVE CROSS

TRACK ANGLE EGATIVE CROSSTRACK ANGLE

CENTRE OF

THE EARTH

CTA - CROSS TRACK ANGLE

Determined by the magnitude of frequency change. Cross Track Angle is the

angle formed between the centre of the earth, the satellite and the beacon.

The smaller the CTA, the closer the satellite is to the beacon (directlyoverhead).

The farther away a beacon is from the path of the satellite, the larger the CTA.






Satellite

Satellite Orbit

Satellite Ground Tra

(path on surface of eaB - Side

Lower probability of

being the actual ELT.

Negative Cross

Track Angle A - Side

Higher probability of

being the actual ELT. Positive Cross

Track Angle

SATELLITE BEACON GEOMETRY

The geometrical calculation which produces the location cannot generatea single, unique location. It always produces 2 locations, approximately

equally spaced on either side of the satellite path. Because the motion of

the earth produces a small, additional doppler effect, it is possible to

estimate which location is more likely to be correct.

(Note: Positive CTA is not always the A-side.)






DOPPLER LOCATION PROCESSING

• Doppler curve defined by four parameters:

1. Cross Track Angle (CTA)

2. Time of Closest Approach (TCA)

3. Frequency Bias4. Frequency Drift

• Beacon location is computed separately from the CTA and

TCA, producing two different locations for the positive

CTA and negative CTA.

• Frequency bias helps identify the beacon

• A solution is calculated using drift (if sufficient data is

available) and no drift. (Solution with drift is used to get

location accuracy. Solution without drift is used tocompute ambiguity probability.)




TITLE: ATLUT Description

PURPOSE: To familiarize the student with EMS’s ATLUT.

Topics:

♦ ATLUT Functions

♦ ATLUT Hardware

♦ ATLUT Rack

♦ ATLUT System Interface Unit

♦ ATLUT Antenna






ADVANCED TECHNOLOGY LOCAL USER

TERMINAL (ATLUT) FUNCTIONS

• Ground based receiving

station

• Tracks satellites• Receives relayed beacon

signals (downlink signal of

1544.5 MHz)

• Calculates satellite position

• Extracts signals from noise

•Estimates Doppler curve

• Calculates Beacon position

(A - side and B - side)

• Estimates beacon parameters

• Transmits locations and

parameters to the Operations

Control Console (OCC)

usually located in the MissionControl Centre (MCC).






ATLUT FUNCTIONS

CONTROLOPERATOR

INTERFACECOMMUNICATIONSPROCESSING

Orbit Data

Maintenance

Set

Parameters

Monitor

Operation

To MCC From MCC406 Bent Pipe

and PDS

Alert

Data

Status

Data

Tracking

Commands

Status

Monitoring

Satellite

TrackingDiagnostics

121.5/243 MHz

Interferer

Location






ATLUT / LEOLUT DATA COLLECTION

SARP

Processed Data Stream (PDS) data — 06 MHz

SARR

Ground Search And Rescue Processor (G-SARP) data — 406 MHz•

• Constant Bin Correlation data — all bands






CBC PROCESSING

Signal Enhancement•

•

•

•

•

•

Frequency Bin Analysis

Template Matching

Weighted Least Squares (WLS) Processing

Variants for 406 MHz — Averaging

Beacon, Interferer, or Unknown Determination






ATLUT HARDWARE

Antenna

Test Horn

Antenna

Control Unit

System

Interface Unit

IF Converter

Test Source

Time Source

Status Monitor

Wide BandProcessor

ALPHA Computer

Low NoiseConverter

Monitor,

Keyboard

and Mouse

Printer

Inside

Outside

GPS Antenna






ATLUT RACK

CAL

Wide BandProcessor

(WBP)

Patch Panel

System

InterfaceUnit (SIU

DecServer Power

Distributio

Unit (PDU






System Interface Unit includes:

• an intermediate frequency downconverter, which converts

the downlink signal from the 44.5 MHz intermediate

frequency signal to the 4.5 MHz baseband required by the

WBP;

• a frequency reference (at 10 MHz) for the entire ATLUT

processing system;

• a GPS time receiver, which provides an accurate external

time reference for the ATLUT;

• a test signal generator and transmitter, which drives the

system self-test; and

• a status monitor unit, used to monitor the status of key

equipment.






LEOLUT ANTENNA

(Cut-away inside the fiberglass Radome)

POWER DIVIDER RF BANDPASS

FILTER

ANTENNA

DISK

LOW NOISE

CONVERTER

(LNC)

ANTENNA

POSITIONER RADOME

ANTENNA

SUPPORT

STRUCTURE






TITLE: GEOLUT Description

PURPOSE: To familiarize the student with EMS’s GEOLUT.

GEOSTATIONARY LOCAL USER

TERMINAL (GEOLUT) FUNCTIONS

• Ground based receiving

station

• Receives relayed beaconsignals (downlink signal of

1544.5 MHz)

• Extracts signals from noise

• Estimates beacon parameters

• Transmits beacon data to the

Operations Control Console

(OCC) usually located in the

Mission Control Centre

(MCC).






GEOLUT FUNCTIONS

CONTROLOPERATOR

INTERFACECOMMUNICATIONSPROCESSING

Status

Monitoring

Set

Parameters

Monitor

Operation

To MCC From MCC406 MHz

Beacon Data

Alert

Data

Status

Data

Diagnostics






GEOLUT HARDWARE

Client WorkstationGPS Antenna

EMS GEOLUT

Antenna

GEOLUT 600






GEOLUT COMPONENTS

• GEOLUT Antenna

• Rack Equipment

♦ Rack Mount Monitor

♦ Rack Mount Keyboard and Mouse

♦ Monitoring Unit

♦ Hub Assembly

♦ GEOLUT Server

Data Aquisition PCB

GPS PCB (c/w GPS Antenna)

56 k Modem

♦ Un-interruptable Power Supply (UPS)

• Client Workstation




TITLE: OCC Description

PURPOSE: To familiarize the student with EMS’s OCC.

Topics:

♦ OCC Functions

♦ Merging Locations/Resolving Ambiguity

♦ GeoSORT

♦ MCC Service Areas

♦ Pass Schedule & Satellite Orbits

♦ Interpreting OCC Solutions

♦ Alert Data Processing

♦ ATLUT/OCC Communications

♦ Key Subject Indicator Types






OCC FUNCTIONS

• Display ELT locations (latitude/longitude),

• Merging locations (resolving ambiguity),

•Automatic alert generation for the RCC(s),

• Automatic alert generation for other countries (MCCs,

SPOCs),

• Manual Alert generation of 121.5/243 and 406 MHz

frequencies for the RCC(s), MCC(s) or SPOC(s),

• Status monitoring of critical tasks and solution files

from ATLUT(s), and

• Pass schedule and ELT report capabilities.








GeoSORT

1. Once a location is determined, the OCC automatically

decides to whom to send the message. This is done by

GeoSort.

2. GeoSort divides the world into the regions of search andrescue responsibility (configured on installation and kept

up to date by the OCC System Manager).

3. SIT message sent to authority in region where beacon is

located. SITs are the computer formatted messages used

to communicate between MCCs of all members of

COSPAS-SARSAT.

4. If the ELT location falls within your own area of Search

and Rescue Responsibility, then the message is sent to

your RCC(s). (May be custom format or SIT.)






MCC SERVICE AREAS

(January 2002)

OTHER AREAS

FMCC

CMCC

USMCC

USMCC

USMCC

FMCC

FMCC

PEMCC

CHMCC

BRMCC

SPMCC

NMCC

CMC

CNMCC

INMCC

AUMCC

ZSMCC

HKMCC

UKMCC

SPMCC

FMCC

ITMCC

FMCC

ITMCC

SAMCC

PAMCC

SIMCC

SIMCC

ALMCC ALMCC






PASS SCHEDULES AND

SATELLITE ORBITS

• Orbit files are automatically sent from the ATLUT to

the OCC (orbit data is in the header of every solution

file sent to the OCC).

• Orbit files are also distributed by USMCC and CMCC.

• It is not necessary to enter the satellite orbit parameters

manually (except on installation, or after problems).

• Satellite orbit parameters are used to create the pass

schedules.

• Pass schedules contain such information as;

∗ when a satellite will be visible to the ATLUT

∗ the duration of the pass

∗ the azimuth and elevation of the pass






INTERPRETING OCC SOLUTIONS

Each time data is processed by an ATLUT it is downloaded and

merged with previous solution data on the OCC Graphics

Screen. The OCC uses eight colours to indicate the status of

solutions and six shapes to indicate the type of solution:

Colour Type of solution

Red Unacknowledged solution

Green Acknowledged single-hit solution

Yellow Acknowledged multiple-hit solution

White Missed solution

Blue Interferer solution

Magenta Marked solution

Turquoise Suppressed solution

Black Highlighted solution

Shape Type of solution

⊕ CBC solution, A-side or resolved location

+ CBC solution, B-side406 MHz solution, current A-side or resolved location

406 MHz solution, current B-side

406 MHz solution, conflicting location, A-side or resolved

location

406 MHz solution, conflicting location, B-side

406 MHz solution, encoded only location






ALERT DATA PROCESSING

Geographically Sort to Determine Appropriate

Destination of Message

Receive Incoming Messages

Sort and Merge

Beacon Locations to

Resolve Ambiguity

Store

Beacon

Data

ATLUT(s) Other MCCs

Generate Outgoing

Messages in the

Required Format

Collect and Maintain

Statistical Information

Transmit

Outgoing

Messages

MCCs/

RCCs/

SPOCs






The ATLUT sends the following files to the OCC:

• WLSDAT contains solutions of 121.5/243.0 MHz beacons.

• WLS406 contains solutions of 406 MHz beacons.

• INT406 contains solutions of 406 MHz interferers.

• WLSDAT and WLS406 files are sent to the OCC when they are

created by the ATLUT at the end of a satellite pass.

• WLS stands for Weighted Least Squares. This is the method used

by the ATLUT to determine the location of the emergency beacon.

• PASS.SCH is a list of which satellites will be tracked, when and

for what duration of time.

• PASS.SCH is sent to the OCC whenever it is built.






KEY SUBJECT INDICATOR TYPES ( SITs)

SIT TITLE MEANING

115 121.5 / 243 Incidents An alert message computed from 121.5 or 243 MHz or

both incident data. The message contains Doppler

position information.

117 121.5 / 243 Ambiguity

Resolution

An alert message with Doppler positions that identifies the

confirmed position of a 121.5/243 MHz signal.121 406 Interferer

Notification

This message is used for notification of 406 MHz

interferer signals.

122 406 Incident

(No Doppler)

A 406 MHz alert message with no Doppler positions. An

encoded position may or may not be available.

123 406 Position Conflict

(Encoded Only)

A 406 MHz alert message with no Doppler positions for

which the encoded position differs by more than the match

criteria from all previous positions.

124 406 Ambiguity

Resolution (EncodedOnly)

A 406 MHz alert message with no Doppler positions that

identifies the resolved position of a 406 MHz alert.

125 406 Incidents A beacon alert message computed from 406 MHz incident

data. The message contains Doppler positions. It may or

may not contain an encoded position.

126 406 Position Conflict A beacon alert messages computed from 406 MHz

incident data. The message contains Doppler and/or

encoded position(s) which may differ from previous

position(s) by the match criteria

127 406 AmbiguityResolution

A 406 MHz alert message with Doppler positions thatidentifies the resolved position of a 406 MHz alert. It may

or may not contain an encoded position.

132 406 Notification of

Country of Registration

(Encoded Only)

This message is used between MCCs to notify the country

of registration of a 406 MHz beacon (NOCR). This

messages contains an encoded position.






KEY SUBJECT INDICATOR TYPES ( SITs)continued

SIT TITLE MEANING

133 406 Notification of

Country of Registration

This message is used between MCCs to notify the country

of registration of a 406 MHz beacon (NOCR). This

message contains Doppler positions. It may or may not

contain an encoded position.

185 COSPAS-SARSATAlerts

This message may be used for 121.5/243/406 MHz alertmessages and as NOCR message between MCCs and

SPOCs.

215 Orbit Vectors SARSAT or COSPAS spacecraft orbit position and time

data message.

415 SARP Calibration Time and Frequency calibration for a SARP.

416 SARP Telemetry SARP Telemetry from a NOAA spacecraft

425 SARP out of limit Warning message to indicate abnormal performance of the

SARP.

435 SARP Command Command request for the SARP.

445 SARP Command

Verification

Verification of the execution ( or non-execution ) of a

SARP command as requested by command message.

510 406 MHZ SARR

Frequency Calibration

Offset

The offset between the actual and the 406 MHz GEO

SARR-provided beacon frequencies.

515 SARR Telemetry SARR telemetry from a NOAA spacecraft.

525 SARR out of limit Warning message to indicate abnormal performance of the

SARR.

535 SARR Command Verification of the execution ( or non-execution ) of a

SARR command as requested by a SARR COMMAND

message.

545 SARR Command

Verification

Command request for the SARR.








TITLE: Typical EMS SAR System

PURPOSE: To familiarize the student with the SAR system configuration.

TYPICAL CONFIGURATION #1

(One ATLUT/One OCC)

Communications

Line

ATLUT

OCC

Other MCCs/RCCs/SPOCs

Telex

AFTN

X.25

Pager






TYPICAL CONFIGURATION #2

(Two ATLUTs/One OCC)

Communications

Line

ATLUT

OCC


Telex

AFTN

X.25

Pager

ATLUT






TYPICAL CONFIGURATION #3(One LEOLUT/One GEOLUT/One MCC)

GEOLUT

OCC


Telex AFTN

X.25Pager

LEOLUT MCC

CommunicationsLine

Documents

TM-CSIN-10001 Intro to Cospas-Sarsat.pdf