# Presentation: 686455

##    Alert Message Formats for SAR Points of Contact (SPOCs)

**   ****Alert Message Formats for SAR Points of Contact (SPOCs)**
** ****- Overview and Interpretation - **

**Tom Griffin, USMCC Senior Systems Analyst**
**U.N./USA Training Course on Satellite Aided Search and Rescue**
**19 – 23 January 2009**

** ****Doppler Location Processing**
** ****Alert Message Formats**
** ****Important Fields in SPOC Messages**
** ****A Complete Sample Message**
**	**
**	**

**Overview**

## Doppler Location Processing

**Primary way to locate 406 MHz beacons in Cospas-Sarsat system**
**Creates two positions  **
-  Real and Image (Initial Alert)
-  Resolved with another satellite pass with Doppler location (pass over    Central America occurs every hour _*on average*_)
- 				 OR
-  Resolved with location encoded in the 406 MHz beacon Id
**	**

**Doppler Location Processing**

## Slide 4

## Alert Message Formats 

**Alert Message Formats **

**Cospas-Sarsat Standard Indicator Type (SIT) 185 Format messages**
**          ****- **Sent by USMCC to most of its international SAR Points of 	Contact (SPOCs**)**
**          ****- ****	**Is the subject of this presentation
**USMCC Special RCC (SIT 160 to 169) Format messages****	**
**          **- Sent by USMCC to a few international SPOCs and all US RCCs
-           - Not discussed further in this presentation
**	**

## Alert Message Formats

**Alert Message Formats**

**SIT 185 Message Title describes the type of data to be sent****	**
- 	406 MHz Initial Alert
- 	406 MHz Position Resolved Alert
- 	406 MHz Position Resolved Update Alert
- 	406 MHz Position Conflict Alert
- 	406 MHz Encoded Position Update Alert
- 	406 MHz Notification of Country of Beacon Registration** **
-     121.5/243.0 MHz Alerts will not be sent as of 1 Feb 2009 (Phaseout)** **
**	**

** **

**Initial Alert** may contain:
- No Doppler location **without** encoded position
- Must use registration information
- No Doppler location **with** encoded position
- Real position normally within 4 seconds (180 meters) of encoded position for Location Protocol beacons
- Doppler location only with an “A” and “B” Positions
- Real position normally within 5 Km of Doppler position
- “A” is correct 90% of the time, **but **use the probability
- Look at “A” and “B” positions – is one side of EPIRB on land?
- Use registration information (use beacon Id on Alert message)
- Contact vessel
- Call owner or Point of Contact
- Check homeport
- Doppler location **and **encoded position
- If matched within 50 km, sent as “Position Resolved Alert”

** ****Alert Message Formats **

## Alert Message Formats

-  **Position Resolved Alert**
-    - Sent when the real position is determined (when ambiguity is 	resolved in previous Doppler “A” and “B” locations)
-    -  Requires match within 50 KM of two _independent_ locations, from
-             Two satellite passes with Doppler location
- 			 OR
- 	      One satellite pass with Doppler location and encoded location
-    - Resolved Position is normally within 4 KM of actual location (if 	encoded location matches resolved position, it is usually more 	accurate than the Doppler position)
**	**

**Alert Message Formats**

** **

-     **Position Resolved Update Alert**
-  	–  Sent when a new position matches the resolved position within 50 km
- 	– Compare the new position and resolved position.  A large distance indicates the beacon may be moving
- 	– Resolved position will get closer to the real position with each  **Position Resolved Update Alert** (if beacon is not moving)
- 	 – USMCC automatically sends a maximum of nine **Position Resolved Update Alerts**
-   - Request the USMCC to continue to send, as needed

**Alert Message Formats**

** **

**Position Conflict Alert**
- Sent when new location(s) differ from previous location(s)
-  	by more than 50 km
- May indicate poor quality location data or a moving beacon
- Prior to ambiguity resolution, any provided location (new or old) may be the real position, but the “A” location with highest probability is most likely to be the real position
- After ambiguity is resolved, new locations are compared only to the resolved position.
- 	  Repeated Position conflicts (without a **Position Resolved ****	****Update Alert**) probably indicates the beacon is moving.

**Alert Message Formats**

** **

**Encoded Position Update Alert **
- Sent when the position encoded in 406 MHz beacon message changes by more than 3 km but less than 50 km
- Likely indicates that the beacon is moving (for example, a beacon at sea is drifting)
- Only sent when new Doppler location not available
- 		If new Doppler and encoded location are available, the 	encoded location is included but not identified in the 		Message Title
- May be sent before or after ambiguity resolution

** ****Alert Message Formats**

** **

**406 MHz Notification of Country of Beacon Registration**
- Sent based on Country encoded in 406 MHz Beacon Id
- Sent to Country of Beacon Registration when alert location is not within that Country’s Search and Rescue (SAR) area
- Allows recipient Country to ensure that there is a SAR response for its beacon owners

** ****Alert Message Formats**

## Important Fields in SPOC Messages

**Important Fields in SPOC Messages**

** ****Message number **
- –** **On first line of SIT message header
- – On line 2 of SIT message body
- –** **Track to ensure all messages are received
- – Reference to discuss a specific message with USMCC

**/****01078**** 00000/3660/09 019 0556 **
**/185/3520 **
**1.  DISTRESS COSPAS-SARSAT POSITION CONFLICT ALERT **
**2.  MSG NO. ****01078****  USMCC REF 47214 **

## Important Fields in SPOC Messages

**Important Fields in SPOC Messages**

** ****USMCC **_**REF**_**erence Number**
**	****– **On line 2 of SIT message body
- 	– Use to discuss beacon activation (site) with USMCC,
- 	   U.S. RCCs and SPOCs in US Service Area
** ****HEX ID**
- – On line 11 of SIT message body
- – Is unique identifier for 406 MHz beacon
- – Used to get access a 406 MHz Beacon Registration Database

**MSG NO. 01078  USMCC REF  ****47214**** **
**11.  HEX ID ****9A89529934D34D1****   HOMING SIGNAL 121.5**

## Important Fields in SPOC Messages

**Important Fields in SPOC Messages**

** ****Message Title**
**	****– **On line 1 of SIT message body
- 	– Describes type of message sent and status of alert site
- 	– Indicates if beacon type is “**DISTRESS**” (most activations)
- 	   or “**SHIP SECURITY**** **”
** ****Detection Frequency**
- – On line 4 of SIT message body
- – Specific frequency (such as 406.025 MHz or 406.028 MHz) may assist search with 406 MHz direction finder

**1.****	****DISTRESS**** COSPAS-SARSAT POSITION RESOLVED  ALERT**
**4.  ****	****DETECTION FREQUENCY  ****406.0248**** MHZ**

## Important Fields in SPOC Messages

**Important Fields in SPOC Messages**

** ****Country of Beacon Registration **
**	****– **On line 5 of SIT message body
**	****– **Derived from 406 MHz beacon Id (in line 11 of SIT message)
- 	– Determines Point of Contact for Registration information
- 	     (provided in line 15 of SIT message)** **
** ****User Class**
- – On line 6 of SIT message body
**	****– **Derived from 406 MHz beacon Id (in line 11 of SIT message)
- –  Provides beacon type (e.g., if EPIRB, location likely not on land)
- –  Use non-serialized Craft Id to get registration data

**5.****	****COUNTRY OF BEACON REGISTRATION   355/PANAMA**
**6.  ****	****USER CLASS - EPIRB MARITIME USER   ID**** ****426000**

## Important Fields in SPOC Messages

**Important Fields in SPOC Messages**

** ****Positions on line 8**
**	****– **Image positions not shown once ambiguity is resolved
**	****– **Use probability when ambiguity is not resolved
**	****– **Encoded position only available for some 406 MHz beacons
**	****– **On **Position Resolved Update Alert, **compare resolved 	 position with the new Doppler/Encoded position(s) to check for  	 a moving beacon.

** **** ****8.  POSITIONS **
**             ****RESOLVED - NIL **
**             ****DOPPLER A- 16 03.0N 101 18.2W   PROB 60 **
**             ****DOPPLER B- 07 37.5N 081 41.4W   PROB 40 **
**             ****ENCODED  - NIL **

## Important Fields in SPOC Messages

**Important Fields in SPOC Messages**

** ****Operational Information on line 15  **(part A)
- – Use to get 406 MHz Registration Data, may be in a National Database or International Beacon Registration Database (IBRD)
-  –  If in IBRD, web address (_**[www.406registration.com](http://www.406registration.com/)**_) is provided

** ****15. OPERATIONAL INFORMATION **
**             ****A. REGISTRATION INFORMATION AT **
**               ****USMCC**
**                ****TELEX: **
**                ****AFTN:    KZDCZSZA**
**                ****TELEPHONE:  1 301-817-4576**
**                ****FACSIMILE:    1 301-817-4568**
**	****      ****EMAIL:  usmcc@noaa.gov**
**	****      ****WEB ADDRESS: **

## Important Fields in SPOC Messages

**Important Fields in SPOC Messages**

** ****Operational Information on line 15 **(parts B, C)
- – Provides the reliability of 406 MHz Doppler position data
- – Provides the likely 406 MHz Doppler image position, when this can be computed from other satellite data (example below and on next page).  “Likely image” does not resolve ambiguity.

** ****15. OPERATIONAL INFORMATION **
**	****  ****B. RELIABILITY OF DOPPLER POSITION DATA -  **
** ****	****  ****C. THE B POSITION IS LIKELY TO BE AN IMAGE POSITION. **

## 406 MHz Image Determination 

**406 MHz Image Determination **
**with GEO Satellite**

**2**

**2A**

**2B**

## Important Fields in SPOC Messages

**Important Fields in SPOC Messages**

**Invalid 406 MHz Beacon Message**
- –  Occurs when component fields do not comply with C/S standards
- –  Associated alert processed based only on Doppler location
- –  No information used from beacon message (including beacon type,   	country code and encoded position)
- –  Alert message shows “NIL” in fields derived from beacon message 	and special Remarks (see example below)

** **** ****16. REMARKS - **
**         **DATA DECODED FROM THE BEACON MESSAGE IS NOT RELIABLE

## Important Fields in SPOC Messages

**Important Fields in SPOC Messages**

** ****Remarks on line 16**
- – For invalid 406 MHz beacon message (see previous example)
- – On Ship Security Alert
- “THIS IS A SHIP SECURITY ALERT. PROCESS THIS ALERT            ACCORDING TO RELEVANT SECURITY REQUIREMENTS.”
- – On Position Conflict Alert    (see example below)

** **** ****16. REMARKS - **
**             ****THIS POSITION MORE THAN 50 KILOMETERS FROM PREVIOUS ALERT **

## Sample Message – Part 1

**Sample Message – Part 1**

**/02109 00000/3660/09 009 0312**
**/185/3450**
**1.  DISTRESS COSPAS-SARSAT RESOLVED ALERT**
**2.  MSG NO. 02109  USMCC REF 18074**
**3.  DETECTED AT 09 JAN 09 0256 UTC BY SARSAT 09**
**4.  DETECTION FREQUENCY 406.0249 MHZ**
**5.  COUNTRY OF BEACON REGISTRATION  366/USA**
**6.  USER CLASS - EPIRB SERIAL   ID 79181**
**7.  EMERGENCY CODE - NONE**
**8.  POSITIONS**
**         ****RESOLVED - 29 09.4N 082 03.9W**
**         ****DOPPLER A- 29 09.2N 082 04.2W   PROB 88**
**         ****DOPPLER B- NIL**
**         ****ENCODED  - NIL**

## Sample Message – Part 2

**Sample Message – Part 2**

**9.  ENCODED POSITION PROVIDED BY: NIL**
**10. NEXT PASS TIMES**
**         ****RESOLVED - 09 JAN 09 0412**
**         ****DOPPLER A- NIL**
**         ****DOPPLER B- NIL**
**         ****ENCODED  - NIL**
**11. HEX ID ADCD04D534C0801   HOMING SIGNAL 121.5**
**12. ACTIVATION TYPE - UNKNOWN**
**13. BEACON NUMBER ON AIRCRAFT OR VESSEL          NIL**
**14. OTHER ENCODED INFORMATION**
**         ****A. BEACON MANUFACTURER AND MODEL NUMBER -**
**            ****MPR/NAT/ SATFIND M3**

## Sample Message – Part 3

**Sample Message – Part 3**

**15. OPERATIONAL INFORMATION**
**         ****A. REGISTRATION INFORMATION AT **
**	****    ****USMCC**
**            ****TELEX:**
**	****    ****AFTN:**
**            ****TELEPHONE: 1 301-817-4576**
**            ****FACSIMILE: 1 301-817-4568**
**            ****EMAIL:  usmcc@noaa.gov**
**            ****WEB ADDRESS:**
**         ****B. RELIABILITY OF DOPPLER POSITION DATA - N/A**
**         ****C. LIKELY DOPPLER IMAGE POSITION - N/A**
**16. REMARKS - NIL**
**END OF MESSAGE**
**/LASSIT**
**/ENDMSG**

## Further Information on SPOC Messages

**Further Information on SPOC Messages**

**Cospas-Sarsat documents**
**    ****A.002 (Standard Interface Description)**
**    ****G.007 (Handbook on Distress Alert Messages for   ****	****	****       RCCs and SPOCs)**
**  ****go to **_**[www.cospas-sarsat.org](http://www.cospas-sarsat.org/)**_
**U.S. RCC/SPOC Message Manual**
**go to **_**[www.sarsat.noaa.gov](http://www.cospas-sarsat.org/)**_
**contact USMCC (tom.griffin@noaa.gov)**

## QUESTIONS!

**QUESTIONS!**