MEOSAR - when will it be fully operational?

Posted by: rafowell

MEOSAR - when will it be fully operational? - 03/12/21 07:12 AM

For years now, I've been reading that emergency beacon receivers on medium earth orbit satellites (GPS/Galileo/GLONASS satellites) will improve the detection time of PLBs/EPIRB distress signals, a capability referred to as MEOSAR.

According to the NOAA page ( MEOSAR) ), there has been some limited capability since 2016.

However, as of last December, four years later, I'm told the system is still not at "Full Operational Capability": MEOLUTs update bringing the Medium Earth...apability (FOC)

Can someone comment on the current and expected status of the MEOSAR system?

All the pages I've seen refer to this as a capability that "will be coming" (e.g., MEOSAR knowledge center )
Posted by: chaosmagnet

Re: MEOSAR - when will it be fully operational? - 03/12/21 01:20 PM

As I understand it, the COSPAS-SARSAT MEOSAR packages are only going on Galileo[*] satellites. There were supposed to be thirty Galileo satellites for a full constellation, but Wikipedia tells me there are 22 satellites in orbit and fully operational.

The European Space Agency (ESA) doesn't appear to have any Galileo launches on their calendar. I wasn't able to find any public documents explaining that right away.

[* - There are three worldwide Global Navigation Satellite Systems, the USA's GPS, Europe's Galileo, and Russia's GLONASS. There are two regional systems, Japan's QZSS and India's NavIC.]
Posted by: rafowell

Re: MEOSAR - when will it be fully operational? - 03/12/21 08:41 PM

Originally Posted By: chaosmagnet
As I understand it, the COSPAS-SARSAT MEOSAR packages are only going on Galileo[*] satellites.

All current MEOSAR packages may be on Galileo satellites. If so, things are far behind schedule.

This January 2011 article Innovation: The Distress Alerting Satellite System, says the MEOSAR concept goes back to 1997,
and that by Jan 2011, nine GPS satellites were hosting proof of concept hardware.

As of June 2015, the page Galileo’s contribution to the MEOSAR system said there were 17 GPS MEOSAR payloads, 6 Galileo payloads, and 2 Glonass payloads, with a forecast (then) of Full Operational Capability in 2019.

This August 2015 article, Canada to Supply MEOSAR Search and Rescue Repeaters to GPS III says 24 repeaters were planned for the GPS III satellites.

The MEOSAR Knowledge Center Media Center article on "First Life Saved" says the first MEOSAR aided rescue was July 2016,
that 12 satellites were active then, the full constellation was planned as 72 satellites (which I think would have to be more than just Galileo),
and that full deployment was expected in 3-5 years ( 2019-2021).

This May 2019 article: MDA to build search-and-rescue repeaters for GPS 3F satellites says the first GPS satellite with a Canadian MEOSAR repeater is scheduled for 2026,
with the first repeaters fully functional in 2027, so unless there are non-Canadian MEOSAR repeaters scheduled for earlier GPS satellites, that leg seems woefully behind schedule.

The table here (scroll down in the page): Status of Cospas-Sarsat MEOSAR Payload Instruments seems to answer my question on the space assets - it lists "Fully Operational" MEOSAR payloads on 34 Galileo satellites, and 18 GPSII satellites, with an puzzling note against the GPSII satellites: "The DASS S-band constellation is not planned to be declared as operational, but its data may be used operationally." It lists three payloads on GLONASS satellites - one as "available for ground segment testing" and two as "Under Test". It also lists two GPSIII satellites as having MEOSAR payloads "under test" but, puzzlingly, doesn't say which of the two GPSIII satellites in orbit they are - maybe they rotate roles!?

It also seems that relatively local MEOSAR ground stations may be required to take advantage of MEOSAR - I see lots of bits about MEOSAR ground stations at various locations.

I still wonder what the back story is on the 18 GPSII satellites with "Fully Operational" space payloads but the system will not be declared operational. One clue is the comment about S-band above - I see at SAR/Galileo Satellites Information that the Galileo MEOSAR repeaters are "fitted with transparent repeater instruments (SARR) operating in the 1544 - 1545 MHz downlink band (L-band) capable to relay Cospas-Sarsat compliant 406 MHz distress signals without on board processing, data storage or demodulation, to any compatible Ground Segment worldwide." - perhaps they decided to change the MEOSAR architecture to L-band, orphaning the S-band GPS MEOSAR payloads?