[time-nuts] GPS SV74/PRN04 now trackable...

[J Grizzard]

Since I figure several people here will be interested, I thought I'd 
note that the first of the new GPS Block III satellites (SV74, launched 
last December) has been assigned PRN04, and is now transmitting the L1 
ranging code and valid LNAV frames. It's currently set unhealthy, so 
most GPS devices won't show it yet, but it's definitely out there now.

I don't know if it's doing anything with L2C (or if it's sending CNAV 
frames yet), mostly because I haven't finished writing my CNAV parser, 
but I suspect it probably is.

Anyhow, from my LNAV parser:

GnssMeta: {
   Page: (uint8) 18,
   Subframe: (uint8) 1,
   SvId: (uint8) 4
},
TLM: {
   Preamble: (uint8) 139,
   Message: (uint16) 10768,
   Integrity: (bool) false,
   Reserved: (bool) false,
},
HOW: {
   TowCountTrunc: (uint32) 86961,
   Alert: (bool) false,
   Antispoof: (bool) true,
   SubframeNumber: (uint8) 1,
},
Data: {
   Wn: (uint16) 28,
   L2_Codes: (uint8) 1,
   UraIndex: (uint8) 0,
   UraMeters: (float32) 0,
   Health: (uint8) 63,
   Iodc: (uint16) 53,
   L2_P_Data: (bool) false,
}

...I should really get around to writing that CNAV parser and such.

-j