Pioneer 10 rx error and tx frequencies?

"ralph sansbury" wrote in message
...

"Craig Markwardt" wrote
in
message news

"ralph sansbury" writes:
But the cd copies of the tapes which I guess you have
access to have problems or at least the copy nasa sent me.
The cd that nasa sent me has data on it that does not
correspond to the TRK-2-25 documentation.
I did a hexadecimal dump of the first file.
The first 32 bits of file "87037.dat" are zero and the
next
eight bits are 3F=0011 1111.That is the next 4 bits are
decimal

Given the garbled and fragmentary nature of the program you
posted, it
is likely that you have a software bug.

As I said that was the program used to get the dump.

The ATDF files I have are
identical to those available on-line for download at NSSDC.
(example:
87037t071.dat = 9209088 bytes). A hex byte dump of the first
16 bytes
is:

00 00 00 00 80 00 00 00 0a 05 70 05 b1 10 12 14,

exactly as expected.

In your notes you say you obtained this directly from the tape
so
it may be that in transferring the tape bytes to the cd that
something happens to produce 3F instead of 80 etc.
The point is I would like to obtain the data you obtained
and
before you filtered it and I would like a program and compiler
to
read it.
Or better yet just use your programs to extract from the
tapes the unfiltered received doppler counter number and the
date and time for 87 and 88 as integers or ansi characters
suitable for input to an excel spreadsheet and send me the cd.



Not according to George: the local oscillator in the
phase
locked loop does not produce an exact match of
the intermediate oscillation version of the received
oscillation. Rather it produces a similar oscillation where
the rising crossings of zero dont always match but
on average

If it is locked in, the loop must detect every cycle. That
is
the very definition of "locked." Your requirement of an "exact"
match is irrelevant to that definition.

But as you see from George's reply here the 'detection of
every
cycle' is too vague.
The real definition seems to be there are the same number of
zero
crossings as the
voltage rises in a 33 minute period but not an exact
correspondence.



Your scenario of 50% missed cycles is
clearly out of lock. With the system used, telemetry can't
be
received until the loop has locked onto the carrier.


If missed cycles means that there are two local oscillator
rising zero crossings before there is a intermediate received
frequency rising zero crossing then this could be made up by
three intermediate received frequency rising zero crossings
during the same time interval there are two local oscillator
rising zero crossings and then one repetition of this etc..
That is over a long enough period eg 33 minutes the average
number of zero crossings in both cases will be the same and yet
clearly there is a lot of noise in the received frequency and
other candidate frequencies with or without their harmonics
might produce the same degree of "lock".


What do you mean by overlapping uplinks and downlinks.?
Do you mean that the assumed time of downlink occurred at
the
same time as an uplink but not at a later time when the
downlink
from this uplink was expected?


I will say this once more. There were cases where uplink
sessions
overlapped in time with downlink sessions, and other cases
where there
was no overlap.
It is not clear at all what you mean by
overlap(complete
or partial?) or consistent. Since all scheduled sessions of
typically four hour durations involved simultaneous
transmission
and reception and complete overlap what do you mean by cases
where this did not happen. How do you know there were cases
where
there was no uplink during the downlinks?
One- invalid- way would be to point to bad received data at
times that implied that there might not have been an uplink at
the assumed earlier uplink time and site.
If there were valid cases of downlinks when no transmission
was going on then I would expect the data received at this time
to be noise.
And it is not obvious that some sort of spurious lock could
occur in these cases and that doppler noise and slipped cycles
in
the data which you said in your notes that you did not
understand
may indicate this.



I analyzed all of this data together, without regard
to the overlap, and the results were entirely consistent.


"Overlap"
is a description of whether uplink and downlink activities
were
happening at the same time or not, period. Absolute uplink
and
downlink epochs are not "assumed," they are measured
precisely.



Nowhere did I say I got rid of data because of overlapping
sessions,
because in fact I kept it.



What do you mean by incoherent tracking sessions. This
is
just jargon for rejecting data not conistent with light
travel
time assumptions.

No. Non-coherent sessions happen when the spacecraft uses
its
own
oscillator, which is susceptible to temperature induced
drifts.
These
types of sessions are useless for radiometric tracking
because
the
clock drift cannot be disentangled from any Doppler-induced
frequency
drift.


That makes sense.

I see the assumed transmitter frequency which you said
was
constant and which in your filter files that I have seen is
always the same although you also say that it can change.??

The uplink frequency can be ramped, but wasn't. The uplink
frequency
was constant for each session.

George and Craig, The point I am trying to make here is
that
different frequency functions may fit the received periodic
waveform regarded as noise plus a specific doppler shifted
version of the know uplink frequency.

The waveform is sinusoidal, so your point is irrelevant.

I doubt that the recieved oscillations of voltage from the
8
Watt transmitter a billion miles away is as 'sine like' as the
local oscillator in the Phase Locked Loop.
The difference between a pure sine mixer oscillator
frequency
and the received frequency may be more sine like than the
received frequency but maybe not.


That is even though the best fit is given by the phase
locked
loop local oscillator frequency etc., various nearby
frequencies
alone or in conjunction with some harmonics could in fact
be
the
true received periodic oscillation..

Which frequencies or harmonics? How can harmonics be
"nearby?"
(they
cannot)
Obviously I mean the harmonics of neaby frequencies

Can you provide (even) a single example? All of the downlink
power spectra I have seen have been flat except for one peak.

But how wide is the peak? To say that a Doppler shift of
so
much has occurred and that a Doppler shift of a slightly
different value has not occurred you need to have a very sharp
peak.
Also the lack of exact matching zeros in the PLL oscillator
and the intermediate received frequency suggests a problem but
maybe not. I wish you or George make a clear, cogent argument
that this lack of matching is not "relevant".
Ralph

Correction: I should have said below that "the program used to
obtain the hex dump" was NOTthe program Craig referred to.

"ralph sansbury" wrote in message
...

"Craig Markwardt" wrote
in
message news

"ralph sansbury" writes:
But the cd copies of the tapes which I guess you have
access to have problems or at least the copy nasa sent me.
The cd that nasa sent me has data on it that does not
correspond to the TRK-2-25 documentation.
I did a hexadecimal dump of the first file.
The first 32 bits of file "87037.dat" are zero and the
next
eight bits are 3F=0011 1111.That is the next 4 bits are
decimal

Given the garbled and fragmentary nature of the program you
posted, it
is likely that you have a software bug.

As I said that was the program used to get the dump.

The ATDF files I have are
identical to those available on-line for download at NSSDC.
(example:
87037t071.dat = 9209088 bytes). A hex byte dump of the first
16 bytes
is:

00 00 00 00 80 00 00 00 0a 05 70 05 b1 10 12 14,

exactly as expected.

In your notes you say you obtained this directly from the tape
so
it may be that in transferring the tape bytes to the cd that
something happens to produce 3F instead of 80 etc.
The point is I would like to obtain the data you obtained
and
before you filtered it and I would like a program and compiler
to
read it.
Or better yet just use your programs to extract from the
tapes the unfiltered received doppler counter number and the
date and time for 87 and 88 as integers or ansi characters
suitable for input to an excel spreadsheet and send me the cd.



Not according to George: the local oscillator in the
phase
locked loop does not produce an exact match of
the intermediate oscillation version of the received
oscillation. Rather it produces a similar oscillation where
the rising crossings of zero dont always match but
on average

If it is locked in, the loop must detect every cycle. That
is
the very definition of "locked." Your requirement of an "exact"
match is irrelevant to that definition.

But as you see from George's reply here the 'detection of
every
cycle' is too vague.
The real definition seems to be there are the same number of
zero
crossings as the
voltage rises in a 33 minute period but not an exact
correspondence.



Your scenario of 50% missed cycles is
clearly out of lock. With the system used, telemetry can't
be
received until the loop has locked onto the carrier.


If missed cycles means that there are two local oscillator
rising zero crossings before there is a intermediate received
frequency rising zero crossing then this could be made up by
three intermediate received frequency rising zero crossings
during the same time interval there are two local oscillator
rising zero crossings and then one repetition of this etc..
That is over a long enough period eg 33 minutes the average
number of zero crossings in both cases will be the same and yet
clearly there is a lot of noise in the received frequency and
other candidate frequencies with or without their harmonics
might produce the same degree of "lock".


What do you mean by overlapping uplinks and downlinks.?
Do you mean that the assumed time of downlink occurred at
the
same time as an uplink but not at a later time when the
downlink
from this uplink was expected?


I will say this once more. There were cases where uplink
sessions
overlapped in time with downlink sessions, and other cases
where there
was no overlap.
It is not clear at all what you mean by
overlap(complete
or partial?) or consistent. Since all scheduled sessions of
typically four hour durations involved simultaneous
transmission
and reception and complete overlap what do you mean by cases
where this did not happen. How do you know there were cases
where
there was no uplink during the downlinks?
One- invalid- way would be to point to bad received data at
times that implied that there might not have been an uplink at
the assumed earlier uplink time and site.
If there were valid cases of downlinks when no transmission
was going on then I would expect the data received at this time
to be noise.
And it is not obvious that some sort of spurious lock could
occur in these cases and that doppler noise and slipped cycles
in
the data which you said in your notes that you did not
understand
may indicate this.



I analyzed all of this data together, without regard
to the overlap, and the results were entirely consistent.


"Overlap"
is a description of whether uplink and downlink activities
were
happening at the same time or not, period. Absolute uplink
and
downlink epochs are not "assumed," they are measured
precisely.



Nowhere did I say I got rid of data because of overlapping
sessions,
because in fact I kept it.



What do you mean by incoherent tracking sessions. This
is
just jargon for rejecting data not conistent with light
travel
time assumptions.

No. Non-coherent sessions happen when the spacecraft uses
its
own
oscillator, which is susceptible to temperature induced
drifts.
These
types of sessions are useless for radiometric tracking
because
the
clock drift cannot be disentangled from any Doppler-induced
frequency
drift.


That makes sense.

I see the assumed transmitter frequency which you said
was
constant and which in your filter files that I have seen is
always the same although you also say that it can change.??

The uplink frequency can be ramped, but wasn't. The uplink
frequency
was constant for each session.

George and Craig, The point I am trying to make here is
that
different frequency functions may fit the received periodic
waveform regarded as noise plus a specific doppler shifted
version of the know uplink frequency.

The waveform is sinusoidal, so your point is irrelevant.

I doubt that the recieved oscillations of voltage from the
8
Watt transmitter a billion miles away is as 'sine like' as the
local oscillator in the Phase Locked Loop.
The difference between a pure sine mixer oscillator
frequency
and the received frequency may be more sine like than the
received frequency but maybe not.


That is even though the best fit is given by the phase
locked
loop local oscillator frequency etc., various nearby
frequencies
alone or in conjunction with some harmonics could in fact
be
the
true received periodic oscillation..

Which frequencies or harmonics? How can harmonics be
"nearby?"
(they
cannot)
Obviously I mean the harmonics of neaby frequencies

Can you provide (even) a single example? All of the downlink
power spectra I have seen have been flat except for one peak.

But how wide is the peak? To say that a Doppler shift of
so
much has occurred and that a Doppler shift of a slightly
different value has not occurred you need to have a very sharp
peak.
Also the lack of exact matching zeros in the PLL oscillator
and the intermediate received frequency suggests a problem but
maybe not. I wish you or George make a clear, cogent argument
that this lack of matching is not "relevant".
Ralph

"ralph sansbury" writes:
"Craig Markwardt" wrote in
message news In your notes you say you obtained this directly from the tape so
it may be that in transferring the tape bytes to the cd that
something happens to produce 3F instead of 80 etc.

No, I obtained the ATDF data from NSSDC over the internet, not tape.


If it is locked in, the loop must detect every cycle. That is
the very definition of "locked." Your requirement of an "exact"
match is irrelevant to that definition.

But as you see from George's reply here the 'detection of every
cycle' is too vague.
The real definition seems to be there are the same number of zero
crossings as the
voltage rises in a 33 minute period but not an exact
correspondence.

"Zero crossings" is your own inappropriate invented language. Still,
George makes it clear that the PLL counts each cycle, with a small
phase residual, always much less than one cycle. Signal lock is
measured on timescales of milliseconds, not 33 minutes.


If there were valid cases of downlinks when no transmission
was going on then I would expect the data received at this time
to be noise.

You are not reading. About 30% of the downlinks (~1400 hours) do not
have an overlapping uplink. The uplink transmitter was turned *OFF*
for those cases (and this is indicated in the telemetry).

Your expectation of noise is incorrect: both the overlapping and
non-overlapping data had the same high quality solution. Again, you
are not reading.

CM

In message , ralph sansbury
writes
Correction: I should have said below that "the program used to
obtain the hex dump" was NOTthe program Craig referred to.

You should learn how to snip your text, too.
--
Rabbit arithmetic - 1 plus 1 equals 10
Remove spam and invalid from address to reply.

Craig,
How do I get access to the data tapes, program and compiler to
read them via the internet?
You and George have not clearly answered the question as to
the possibility and probability of sine functions with other
frequencies near the one frequency detected using the FFT
procedure and phase locked loops.
This is not an inappropriate or irrelevant question.
Ralph
wrote in message
news

"ralph sansbury" writes:
"Craig Markwardt"
wrote in
message news In your notes you say you obtained this directly from the
tape so
it may be that in transferring the tape bytes to the cd that
something happens to produce 3F instead of 80 etc.

No, I obtained the ATDF data from NSSDC over the internet, not
tape.


If it is locked in, the loop must detect every cycle. That
is
the very definition of "locked." Your requirement of an
"exact"
match is irrelevant to that definition.

But as you see from George's reply here the 'detection of
every
cycle' is too vague.
The real definition seems to be there are the same number of
zero
crossings as the
voltage rises in a 33 minute period but not an exact
correspondence.

"Zero crossings" is your own inappropriate invented language.
Still,
George makes it clear that the PLL counts each cycle, with a
small
phase residual, always much less than one cycle. Signal lock
is
measured on timescales of milliseconds, not 33 minutes.


If there were valid cases of downlinks when no
transmission
was going on then I would expect the data received at this
time
to be noise.

You are not reading. About 30% of the downlinks (~1400 hours)
do not
have an overlapping uplink. The uplink transmitter was turned
*OFF*
for those cases (and this is indicated in the telemetry).

Your expectation of noise is incorrect: both the overlapping
and
non-overlapping data had the same high quality solution.
Again, you
are not reading.

CM

"Craig Markwardt" wrote in message
news

"ralph sansbury" writes:

But as you see from George's reply here the 'detection of every
cycle' is too vague.
The real definition seems to be there are the same number of zero
crossings as the
voltage rises in a 33 minute period but not an exact
correspondence.

"Zero crossings" is your own inappropriate invented language.

Actually I suspect I introduced it. It is standard terminology
in my line of business.

Still,
George makes it clear that the PLL counts each cycle, with a small
phase residual, always much less than one cycle. Signal lock is
measured on timescales of milliseconds, not 33 minutes.

I think lock is likely to change on timescales of ~1s due
to the narrow (1Hz) bandwidth of the PLL loop filter.

These don't affect your points Craig, just setting the record
straight.

best regards
George

"ralph sansbury" wrote in message ...
...
You and George have not clearly answered the question as to
the possibility and probability of sine functions with other
frequencies near the one frequency detected using the FFT
procedure and phase locked loops.

That would require another spacecraft using a nearby
frequency to be within the beamwidth of the DSN antenna.
I have no idea how to assess that risk but the data
returned would soon identify the fact that they had
locked on to the wrong craft.

This is not an inappropriate or irrelevant question.

It is a reasonable question but a highly unlikely
scenario given some basic mission planning.

George

"George G. Dishman" wrote in message
om...
"ralph sansbury" wrote in message
...
..
You and George have not clearly answered the question as
to
the possibility and probability of sine functions with other
frequencies near the one frequency detected using the FFT
procedure and phase locked loops.

That would require another spacecraft using a nearby
frequency to be within the beamwidth of the DSN antenna.

Or it could mean that the frequency received had more or
less Doppler shift than predicted.
You say that the output of the FFT algorithm is to produce a
graph of the power around various frequencies and that typically
here you get a lot of power around one frequency and that other
frequencies over a wider range have .01 of the power of this
major frequency.
You say that you get a normal curve with the peak at this
frequency and that you integrate under the curve to get the power
and that would seem to imply your summands or integrands include
power associated with greater and lesser frequencies around the
central frequency.
This says to me that the peak frequency is the most likely
frequency in this particular "sample" but that a .99 confidence
interval for the "population" frequency would plus or minus 3
standard deviations around this sample frequency.
The sample of the population here could be regarded as many
hypothetical repetitions of the receiving of radiation procedure
over the same time interval.

I have no idea how to assess that risk but the data
returned would soon identify the fact that they had
locked on to the wrong craft.

This is not an inappropriate or irrelevant question.

It is a reasonable question but a highly unlikely
scenario given some basic mission planning.

George

Craig,
I would like to obtain the Pioneer 10 Doppler data you
obtained
and before you filtered it.

1)Could you use your programs to extract from the
tapes the unfiltered received doppler counter number and the
date and time for 87 and 88 as integers or ansi characters
suitable for input to an excel spreadsheet and send me the cd.
or 2) Could you send me a program and compiler to read the
original data from the internet.
Ralph Sansbury

"ralph sansbury" wrote in message
...

"Craig Markwardt" wrote
in
message news

"ralph sansbury" writes:
But the cd copies of the tapes which I guess you have
access to have problems or at least the copy nasa sent me.
The cd that nasa sent me has data on it that does not
correspond to the TRK-2-25 documentation.
I did a hexadecimal dump of the first file.
The first 32 bits of file "87037.dat" are zero and the
next
eight bits are 3F=0011 1111.That is the next 4 bits are
decimal
As I said a different program and computer were used to
get the dump.

The ATDF files I have are
identical to those available on-line for download at NSSDC.
(example:
87037t071.dat = 9209088 bytes). A hex byte dump of the first
16 bytes
is:

00 00 00 00 80 00 00 00 0a 05 70 05 b1 10 12 14,

exactly as expected.

In your notes you say you obtained this directly from the tape
so
it may be that in transferring the tape bytes to the cd that
something happens to produce 3F instead of 80 etc.
The point is I would like to obtain the data you obtained
and
before you filtered it and I would like a program and compiler
to
read it.
Or better yet just use your programs to extract from the
tapes the unfiltered received doppler counter number and the
date and time for 87 and 88 as integers or ansi characters
suitable for input to an excel spreadsheet and send me the cd.

"ralph sansbury" wrote in message
...

"George G. Dishman" wrote in message
om...
"ralph sansbury" wrote in message
...
..
You and George have not clearly answered the question as to
the possibility and probability of sine functions with other
frequencies near the one frequency detected using the FFT
procedure and phase locked loops.

That would require another spacecraft using a nearby
frequency to be within the beamwidth of the DSN antenna.

Or it could mean that the frequency received had more or
less Doppler shift than predicted.

No, that would result in a single peak somewhere other
than the expected position. In fact that is the nature
of the anomaly reported by Anderson et al, the signal
at the end of 1994 was about 3Hz away from where it
was expected.

You asked about the possibility of another signal "near the
one frequency detected" implying two signals.

You say that the output of the FFT algorithm is to produce a
graph of the power around various frequencies and that typically
here you get a lot of power around one frequency and that other
frequencies over a wider range have .01 of the power of this
major frequency.

The value of 0.01 was a single example Craig gave (I think).
The ratio would be much higher when Pioneer was closer to
Earth and was approaching 1:1 when it was lost a year or two
ago.

You say that you get a normal curve with the peak at this
frequency and that you integrate under the curve to get the power
and that would seem to imply your summands or integrands include
power associated with greater and lesser frequencies around the
central frequency.

Jitter turns a high narrow peak into a smaller, broader peak.
The total power is just that fraction of what was transmitted
that impinges on the receive anntenna.

This says to me that the peak frequency is the most likely
frequency in this particular "sample" but that a .99 confidence
interval for the "population" frequency would plus or minus 3
standard deviations around this sample frequency.
The sample of the population here could be regarded as many
hypothetical repetitions of the receiving of radiation procedure
over the same time interval.

It is more complex. For random noise you have a distibution
of component amplitudes and the probability of getting a
false detection depends on how far above the mean level you
set the threshold. There are two factors, the noise has to
be much higher than average and the signal has to be much
lower than the average, both rare events anway, before the
noise can exceed the signal.

Again though, such a false detection is incredibly unlikely
to be repeated at the same frequency on the repeat test done
some time later on a new set of samples, the PLL would not
lock on, the sub-carrier would not be present and the data
correction would indicate an unusable Bit Error Rate.

George