"Flarm, no GPS"

At 00:31 05 July 2015, jfitch wrote:
On Thursday, July 2, 2015 at 10:12:49 PM UTC-7, jfitch wrote:
I am getting this bitching Betty alarm every so often. It may do it for
a=
minute or so, then goes away, then comes again.=20
=20
Looking at the Flarm IGC file, there are comment lines that look like
thi=
s:
=20
LFLA213757GPS 7 45=20
=20
Which I believe represents GPS status (7 satellites?)
=20
Then I get some that look like this:
=20
LFLA213857GPS 0 0
=20
No satellites? The B field time stamps show a lat and long 4 seconds
befo=
re and 4 seconds after. In the flight today I got 14 of these and about
tha=
t many warnings (I didn't count the warnings).=20
=20
This didn't happen last year, started coincident with the 6.0.2
firmware
=
"upgrade".=20
=20
Can anyone shed any light on this? Can't find any spec from Flarm that
de=
scribes it.

I have now written an XL parser for the Flarm IGC file, which counts the
in=
stances of dropped fixes. I found no dropped fixes at all from flights in
2=
013. I found dropped fixes in one flight in 2014, 56 dropped on one
particu=
lar flight, none in any others. I have now 3 flights in 2015 with the new
f=
irmware. 1st flight shows 19 dropped fixes, 2nd flight 373 dropped fixes,
3=
rd flight 882 (and all fairly short flights too). Not an encouraging
trend.=
=20

The reason I am now aware of it, is that the new Flarm firmware announces
b=
ad fixes with the Lxxxxxx GPS 0 0 comment line, and the Air Vario
announces=
it to me with a voice warning. Didn't do that before.

Not beyond the bounds of possibility that reporting No GPS in the L-record
is a new feature Introduced with Version 6?

On Sunday, July 5, 2015 at 10:00:07 AM UTC-7, Tim Newport-Peace wrote:
At 00:31 05 July 2015, jfitch wrote:
On Thursday, July 2, 2015 at 10:12:49 PM UTC-7, jfitch wrote:
I am getting this bitching Betty alarm every so often. It may do it for
a=
minute or so, then goes away, then comes again.=20
=20
Looking at the Flarm IGC file, there are comment lines that look like
thi=
s:
=20
LFLA213757GPS 7 45=20
=20
Which I believe represents GPS status (7 satellites?)
=20
Then I get some that look like this:
=20
LFLA213857GPS 0 0
=20
No satellites? The B field time stamps show a lat and long 4 seconds
befo=
re and 4 seconds after. In the flight today I got 14 of these and about
tha=
t many warnings (I didn't count the warnings).=20
=20
This didn't happen last year, started coincident with the 6.0.2
firmware
=
"upgrade".=20
=20
Can anyone shed any light on this? Can't find any spec from Flarm that
de=
scribes it.

I have now written an XL parser for the Flarm IGC file, which counts the
in=
stances of dropped fixes. I found no dropped fixes at all from flights in
2=
013. I found dropped fixes in one flight in 2014, 56 dropped on one
particu=
lar flight, none in any others. I have now 3 flights in 2015 with the new
f=
irmware. 1st flight shows 19 dropped fixes, 2nd flight 373 dropped fixes,
3=
rd flight 882 (and all fairly short flights too). Not an encouraging
trend.=
=20

The reason I am now aware of it, is that the new Flarm firmware announces
b=
ad fixes with the Lxxxxxx GPS 0 0 comment line, and the Air Vario
announces=
it to me with a voice warning. Didn't do that before.

Not beyond the bounds of possibility that reporting No GPS in the L-record
is a new feature Introduced with Version 6?

As I said, this was introduced in V6. The same information was available in the B record in prior versions, but you had to dig for it a bit more. Of course the Vario is not looking at the IGC file, only the serial stream, which I do not have the equipment to directly capture, so I do not know what changes where made to it, and what changes to the interpretation.

At 05:54 06 July 2015, jfitch wrote:
On Sunday, July 5, 2015 at 10:00:07 AM UTC-7, Tim Newport-Peace wrote:
At 00:31 05 July 2015, jfitch wrote:
On Thursday, July 2, 2015 at 10:12:49 PM UTC-7, jfitch wrote:
I am getting this bitching Betty alarm every so often. It may do it
fo=
r
a=3D
minute or so, then goes away, then comes again.=3D20
=3D20
Looking at the Flarm IGC file, there are comment lines that look
like
thi=3D
s:
=3D20
LFLA213757GPS 7 45=3D20
=3D20
Which I believe represents GPS status (7 satellites?)
=3D20
Then I get some that look like this:
=3D20
LFLA213857GPS 0 0
=3D20
No satellites? The B field time stamps show a lat and long 4 seconds
befo=3D
re and 4 seconds after. In the flight today I got 14 of these and
about
tha=3D
t many warnings (I didn't count the warnings).=3D20
=3D20
This didn't happen last year, started coincident with the 6.0.2
firmware
=3D
"upgrade".=3D20
=3D20
Can anyone shed any light on this? Can't find any spec from Flarm
that
de=3D
scribes it.

I have now written an XL parser for the Flarm IGC file, which counts
the
in=3D
stances of dropped fixes. I found no dropped fixes at all from flights
i=
n
2=3D
013. I found dropped fixes in one flight in 2014, 56 dropped on one
particu=3D
lar flight, none in any others. I have now 3 flights in 2015 with the
ne=
w
f=3D
irmware. 1st flight shows 19 dropped fixes, 2nd flight 373 dropped
fixes=
,
3=3D
rd flight 882 (and all fairly short flights too). Not an encouraging
trend.=3D
=3D20

The reason I am now aware of it, is that the new Flarm firmware
announce=
s
b=3D
ad fixes with the Lxxxxxx GPS 0 0 comment line, and the Air Vario
announces=3D
it to me with a voice warning. Didn't do that before.

Not beyond the bounds of possibility that reporting No GPS in the
L-recor=
d
is a new feature Introduced with Version 6?

As I said, this was introduced in V6. The same information was available
in=
the B record in prior versions, but you had to dig for it a bit more. Of
c=
ourse the Vario is not looking at the IGC file, only the serial stream,
whi=
ch I do not have the equipment to directly capture, so I do not know what
c=
hanges where made to it, and what changes to the interpretation.

Have you looked at the .IGC records that begin with "F"? These contain
firstly the time, followed by pairs of characters which give the satellite
ID? These records should occur at leats every five minutes.

On Sunday, July 5, 2015 at 11:45:06 PM UTC-7, Tim Newport-Peace wrote:
At 05:54 06 July 2015, jfitch wrote:
On Sunday, July 5, 2015 at 10:00:07 AM UTC-7, Tim Newport-Peace wrote:
At 00:31 05 July 2015, jfitch wrote:
On Thursday, July 2, 2015 at 10:12:49 PM UTC-7, jfitch wrote:
I am getting this bitching Betty alarm every so often. It may do it
fo=
r
a=3D
minute or so, then goes away, then comes again.=3D20
=3D20
Looking at the Flarm IGC file, there are comment lines that look
like
thi=3D
s:
=3D20
LFLA213757GPS 7 45=3D20
=3D20
Which I believe represents GPS status (7 satellites?)
=3D20
Then I get some that look like this:
=3D20
LFLA213857GPS 0 0
=3D20
No satellites? The B field time stamps show a lat and long 4 seconds
befo=3D
re and 4 seconds after. In the flight today I got 14 of these and
about
tha=3D
t many warnings (I didn't count the warnings).=3D20
=3D20
This didn't happen last year, started coincident with the 6.0.2
firmware
=3D
"upgrade".=3D20
=3D20
Can anyone shed any light on this? Can't find any spec from Flarm
that
de=3D
scribes it.

I have now written an XL parser for the Flarm IGC file, which counts
the
in=3D
stances of dropped fixes. I found no dropped fixes at all from flights
i=
n
2=3D
013. I found dropped fixes in one flight in 2014, 56 dropped on one
particu=3D
lar flight, none in any others. I have now 3 flights in 2015 with the
ne=
w
f=3D
irmware. 1st flight shows 19 dropped fixes, 2nd flight 373 dropped
fixes=
,
3=3D
rd flight 882 (and all fairly short flights too). Not an encouraging
trend.=3D
=3D20

The reason I am now aware of it, is that the new Flarm firmware
announce=
s
b=3D
ad fixes with the Lxxxxxx GPS 0 0 comment line, and the Air Vario
announces=3D
it to me with a voice warning. Didn't do that before.

Not beyond the bounds of possibility that reporting No GPS in the
L-recor=
d
is a new feature Introduced with Version 6?

As I said, this was introduced in V6. The same information was available
in=
the B record in prior versions, but you had to dig for it a bit more. Of
c=
ourse the Vario is not looking at the IGC file, only the serial stream,
whi=
ch I do not have the equipment to directly capture, so I do not know what
c=
hanges where made to it, and what changes to the interpretation.

Have you looked at the .IGC records that begin with "F"? These contain
firstly the time, followed by pairs of characters which give the satellite
ID? These records should occur at leats every five minutes.

I have looked at them, they are unremarkable. They do not appear near the dropped fixes. The IGC spec requires them only every 5 minutes or when the constellation changes.