GPS L5 signals

[oldbob]

Since June 2022, my 66sr satellite page has displayed an L5 signal for only one GPS Block III satellite (PRN 4). Are the other four Block III satellites (11, 14, 18, 23) not transmitting an L5 signal? My 66sr does display an L5 signal for Block IIF and Galileo satellites. I noticed on the post by mimiecrist? (66sr and L5) that his log listed PRN 4 as one of his L5 sources. Is there a web site for GPS L5 signal status?

[mimichris]

Indeed, I also noticed that often the GPS system has very few L5 satellites, sometimes only one or two. Compared to the Galileo which has all its E1a satellites in E5a, at least on the 66sr.

[0x01]

Is there a web site for GPS L5 signal status?

Yes:

Spoiler

https://www.gps.gov/systems/gps/moderni ... ilsignals/

The new civil signals are phasing in incrementally as the Air Force launches new GPS satellites to replace older ones. Most of the new signals will be of limited use until they are broadcast from 18 to 24 satellites.

Third Civil Signal: L5
Status
Pre-operational signal with message set "unhealthy" until sufficient monitoring capability established
Broadcasting from 17 GPS satellites (as of June 26, 2022)
Began launching in 2010 with GPS Block IIF
Available on 24 GPS satellites ~2027 (as of Jan 2020)

[GPSrChive]

Is there a web site for GPS L5 signal status?

Yes:

Spoiler

https://www.gps.gov/systems/gps/moderni ... ilsignals/

The new civil signals are phasing in incrementally as the Air Force launches new GPS satellites to replace older ones. Most of the new signals will be of limited use until they are broadcast from 18 to 24 satellites.

Third Civil Signal: L5
Status
Pre-operational signal with message set "unhealthy" until sufficient monitoring capability established
Broadcasting from 17 GPS satellites (as of June 26, 2022)
Began launching in 2010 with GPS Block IIF
Available on 24 GPS satellites ~2027 (as of Jan 2020)

I found this part from your link most interesting:

In April 2014, the Air Force began broadcasting civil navigation (CNAV) messages on the L5 signal. However, L5 remains pre-operational and should be employed at the user's own risk until it is declared operational.

[mimichris]

Indeed on my MI9 smartphone and GPSTest, the L5 satellites are unstable compared to the E5a Galileo satellites. Sometimes I have five, then it drops to two then three, so I think they are ineffective.

[oldbob]

Hello, thanks for replying. By an L5 status web site, I meant one that list each GPS L5 capable satellite (12 Block IIF and 5 Block III) and details their current status (transmitting or not, message capable or not, available to be received, etc). The references mentioned that "17 L5 satellites were transmitting as of June 2022". Is that continuous or not and capable to be received by consumer receivers? My 66sr only receives PRN 4 of the 5 Block III satellites. Is my 66sr not working properly? Does anyone else receive and display those other 4 Block III Satellites on their 66sr's or phones? What is the 66sr's criteria for receiving and displaying the L5 signals? Is the 66sr accuracy affected by relying on E5 signals from Galileo? On that note, it appears that the Galileo constellation takes a long time to appear on my Satellite page. I use the WAAS status site to determine when to look for certain satellites overhead.

[GPSrChive]

How are you determining which satellites have L5 capability?

[oldbob]

Block IIF satellites were the first to include the L5 frequency band in their basic design. Block III has L5 and Block IIIF will have it. Earlier Block IIR and Block IIRM did not have L5 (the ill-fated Block IIRM-7 SVN 49 had L5 added on at the last minute (without adequate testing) in order to "reserve" the frequency band for GPS).

[GPSrChive]

Thank you for sharing your information here.

We are currently unaware of any service providing a list of 'Active L5 GPS Satellites'.

Should you find a source for this information, please also share that here!

In case you have not yet seen it, we have some GNSS information at GPSrChive > GNSS.

[0x01]

By an L5 status web site, I meant one that list each GPS L5 capable satellite (12 Block IIF and 5 Block III) and details their current status (transmitting or not, message capable or not, available to be received, etc).

You can at least monitor satellite status on this page for example: https://www.gnssplanning.com/
If you determine either by an other source or by your GPSr the L5 capable satellites, you can select them and check their overall state and visibility.
Yes, I understand you like to know specifically the L5 status for each and not overall status.