This is an extraction and large cleanup of AMSA's COSPAS-SARSAT First Generation Beacon hexId and detection message decode java source code (originally in aussar-oracle-java project). The decode is compliant with the C/S T.001 Issue 4 Revision 10 specification with the exception of the ELT(DT) Location Protocol (see #117). The specification can be downloaded from COSPAS-SARSAT System Documents.

The cleanup included:

• use JSON types like int, double, boolean instead of pure text fields (YES = true etc)
• search through 100,000 historical FGB messages to increase test coverage to over 90%
• create enumerated types
• a large refactoring to deal with a huge amount of copy-and-paste!

There's plenty of legacy ugliness in there still but should be enough for AMSA's use cases.

Status: production

Maven reports including javadocs

See also: sgb-decoder to decode Second Generation Beacon Hex Ids and detection messages.

Add this dependency to your pom.xml:

<dependency>
  <groupId>au.gov.amsa</groupId>
  <artifactId>fgb-decoder</artifactId>
  <version>VERSION_HERE</version>
</dependency>

To decode a 15 character hex beacon identifier:

String json = Beacon15HexId.decodeHexToJson(hex);

To decode a 30 character hex beacon detection message:

String json = Detection.decodeHexToJson(hex);

The hexId ADCC40504000185 decodes to:

{
"messageType": "User (Format - Unknown)",
"hexData": "Unknown",
"hexId": "ADCC40504000185",
"countryCode": 366,
"userProtocolType": "Serial",
"beaconType": "Aviation",
"cSCertNumberPresent": true,
"serialNumber": 5136,
"nationalUse": "0000000000",
"cSTypeApprovalNumber": 97,
"auxiliaryRadioLocatingDevice": "121.5 MHz",
"uSManufacturerId": 1,
"uSSequenceNumber": 1040,
"uSModelId": 0,
"uSRunNumber": 0,
"uSNationalUse": "01100001"
}

The detection message D6E6202820000C29FF51041775302D decodes to:

{
"messageType": "User Location (Long)",
"hexData": "D6E6202820000C29FF51041775302D",
"hexId": "ADCC40504000185",
"countryCode": 366,
"userProtocolType": "Serial",
"beaconType": "Aviation",
"cSCertNumberPresent": true,
"serialNumber": 5136,
"nationalUse": "0000000000",
"cSTypeApprovalNumber": 97,
"auxiliaryRadioLocatingDevice": "121.5 MHz",
"uSManufacturerId": 1,
"uSSequenceNumber": 1040,
"uSModelId": 0,
"uSRunNumber": 0,
"uSNationalUse": "01100001",
"errorCorrectingCode1": "001111111110101000100",
"encodedPositionSource": "EXTERNAL",
"latitude": 32.733333333333334,
"longitude": -117.2,
"errorCorrectingCode2": "000000101101"
}

mvn clean install

To build a release:

• git checkout master
• ./release.sh <VERSION>
• go to Github project and publish a release (look at previous releases to see what goes in the release description field)
• in the Github project go to Actions and check to see if the release has made its way to Maven Central successfully
• git checkout <VERSION> && ./generate-site.sh (requires repo amsa-code.github.io to be sitting next to fgb-decoder)
• change the fgb-decoder version in beacon-decoder-aws and run its release script (which deploys it to AWS)
• change the fgb-decoder version in parent/beacon-decoder and redeploy it to Tomcat on sar*.