GPS satelllite view question

[Nick Taylor]

Hi all

General question on satellite orbits...

We have a test lab where they have a row of GPS antenna mounted in 
window - apparently single glazed.

They have been operating like this for years and haven't reported 
problems to us before - although that's not to say that they didn't have 
problems and not tell anyone.

My question is... I realise that in ideal world GPS should have as full 
view of sky as possible, but is it expected in the above scenario that 
there can be periods of time (hours to days) where the portion of sky 
visible by these GPS antenna in window can fail to see any satellite data

That's what I suspect is happening there at the moment (multiple 
independent units showing same symptoms):
$GLGSA,A,1,,,,,,,,,,,,,,,*02
$GNRMC,140143.000,V,,,,,0.00,21.37,231122,,,N*66
$GNZDA,140143.000,23,11,2022,,*48
$GPGRS,140143.000,1,,,,,,,,,,,,*7D
$GPGST,140143.000,12,99999,99999,82.4,99999,99999,10082*62
$GNGGA,140144.000,,,,,0,0,,,M,,M,,*52
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GLGSA,A,1,,,,,,,,,,,,,,,*02
$GNRMC,140144.000,V,,,,,0.00,21.37,231122,,,N*61
$GNZDA,140144.000,23,11,2022,,*4F
$GPGRS,140144.000,1,,,,,,,,,,,,*7A
$GPGST,140144.000,12,99999,99999,82.4,99999,99999,10082*65
$GNGGA,140145.000,,,,,0,0,,,M,,M,,*53
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GLGSA,A,1,,,,,,,,,,,,,,,*02
$GPGSV,3,1,10,15,77,248,,13,66,120,,14,44,065,,24,36,257,*74
$GPGSV,3,2,10,23,32,306,,05,22,193,,30,18,074,,17,14,101,*78
$GPGSV,3,3,10,10,10,329,,18,05,271,*78
$GLGSV,1,1,00*65
$GNRMC,140145.000,V,,,,,0.00,21.37,231122,,,N*60
$GNZDA,140145.000,23,11,2022,,*4E
$GPGRS,140145.000,1,,,,,,,,,,,,*7B
$GPGST,140145.000,12,99999,99999,82.5,99999,99999,10082*65
$GNGGA,140146.000,,,,,0,0,,,M,,M,,*50
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GLGSA,A,1,,,,,,,,,,,,,,,*02
$GNRMC,140146.000,V,,,,,0.00,21.37,231122,,,N*63
$GNZDA,140146.000,23,11,2022,,*4D
$GPGRS,140146.000,1,,,,,,,,,,,,*78
$GPGST,140146.000,12,99999,99999,82.1,99999,99999,10083*63

Comments welcome

Thanks

Nick