Ranging and Pioneer

Oh No wrote:
The position of Pioneer was calculated from Doppler information.

This statement is misleading. The position(s) of Pioneer(s) at any
given time was calculated using classical trajectory dynamics (with GR
corrections taken into account). So was the anticipated velocity hence
Doppler shift of antenna signal at any given time. What was observed by
NASA/JPL was an accumulating deviation from predicted Doppler shift,
which led Anderson et al. to infer an apparent classically anomalous
acceleration of the probes.

These apparent classically anomalous accelerations were tabulated
against predicted positions, not against altered positions inferred
from such apparent classically anomalous accelerations of the probes.

John (Liberty) Bell
http://global.accelerators.co.uk
(Change John to Liberty to respond by email)

Oh No wrote:

The position of Pioneer was calculated from Doppler information. Ranging
was not available. Can anyone explain why ranging could not be used? Is
this just a limit on available technology, or is there a more
fundamental reason?


Regards

The following reference provides a mission
to quantify the anomalous effect with ranging capability:

ref1:A MISSION TO EXPLORE THE PIONEER ANOMALY
H. Dittus, S.G. Turyshev, J.D. Anderson et al
http://arxiv.org/pdf/gr-qc/0506139
3.3. A Dedicated Mission Concept

Quote
"In particular,
we emphasize a precision formation flying as a feasible
flight system concept for the proposed mission. For
this architecture, a passive sphere covered with cornercube
retroreflectors is laser-ranged from the primary craft."
Unquote

This is an excellent idea.
My fear is that 'area to mass' ratio
will not be designed into the "passive sphere"

If the "passive sphere" is designed
as a bowling ball rather than a soccer ball
the anomalous deceleration effect will not be measured above the noise.

Why not have several passive objects
with an array of geometric shapes (Platonic solids for a start)
with a range of 'area to mass' ratios
all fitted with cornercube retroreflectors
and ranged from the primary craft.

Ref2:
Seconds of Data, Years of Trying
Photonics Spectra, May 2006 Vol 40, Issue 5, p 56

This reference provides a good perspective
on capability of detecting laser space ranging data
within the context of receiving ranging information from the
Messenger Mission to Mercury.
After much effort, the distance
to the Laser Altimeter Instrument
on the Messenger Mission to Mercury
was measured at 23,964,675,433.9 +/- .2 m.
(14,890,958.9 statute miles)
(~.16 AU)

Ref1 would appear to be the only reasonable approach
for ranging small distant (from earth) space object trajectories

Richard Saam

Richard Saam wrote:
Oh No wrote:

The position of Pioneer was calculated from Doppler information. Ranging
was not available. Can anyone explain why ranging could not be used? Is
this just a limit on available technology, or is there a more
fundamental reason?


Regards


Here is an extreme case
in terms of Beta Pictoris
at many light years distance

arXiv:astro-ph/0601244 v1 11 Jan 2006

Dynamic motions are inferred from
atomic molecular quantum transitions.

The time (frequency) of such transitions are assumed the same
there and here
from which observed differences in frequencies
are related to dynamic motions.

The problem is the same as you identify.
How does one "range" the motions of Asteroid size objects
(which do not have quantum transitions) in Beta Pictoris
other than observing the gross newtonian gravity motions of the system
as a whole.

The problem could be solved if only a radar signal could be sent,
reflected for obtaining active ranging information.

In fact, with the (still functional) Pioneer, the possibility of
obtaining ranging data is enhanced by the fact that it contains a
narrow beam broadcast antenna directed towards the Earth, which can be
turned on and off via ground control.

Whether or not NASA thought to accuirately design and measure such turn
on/off delays prior to launch, in order to facilitate such a ranging
test, is, of course, another matter.

John (Liberty) Bell
http://global.accelerators.co.uk
(Change John to Liberty to respond by email)

In message .com,
"John (Liberty) Bell" writes

Richard Saam wrote:
Oh No wrote:

The position of Pioneer was calculated from Doppler information. Ranging
was not available. Can anyone explain why ranging could not be used? Is
this just a limit on available technology, or is there a more
fundamental reason?


Regards


Here is an extreme case
in terms of Beta Pictoris
at many light years distance

arXiv:astro-ph/0601244 v1 11 Jan 2006

Dynamic motions are inferred from
atomic molecular quantum transitions.

The time (frequency) of such transitions are assumed the same
there and here
from which observed differences in frequencies
are related to dynamic motions.

The problem is the same as you identify.
How does one "range" the motions of Asteroid size objects
(which do not have quantum transitions) in Beta Pictoris
other than observing the gross newtonian gravity motions of the system
as a whole.

The problem could be solved if only a radar signal could be sent,
reflected for obtaining active ranging information.

In fact, with the (still functional) Pioneer, the possibility of
obtaining ranging data is enhanced by the fact that it contains a
narrow beam broadcast antenna directed towards the Earth, which can be
turned on and off via ground control.

Whether or not NASA thought to accuirately design and measure such turn
on/off delays prior to launch, in order to facilitate such a ranging
test, is, of course, another matter.

Even when Pioneer 10 and 11 were fully functional (and contact was lost
with 11 in 1995 and 10 in 2003) the fact remains that they couldn't do
the type of ranging involving transmitting and receiving a modulated
signal that was done with Galileo and Ulysses. They certainly wouldn't
have used anything as drastic as turning the transmitter on and off.

In message .com,
"John (Liberty) Bell" writes

Richard Saam wrote:
Oh No wrote:

The position of Pioneer was calculated from Doppler information. Ranging
was not available. Can anyone explain why ranging could not be used? Is
this just a limit on available technology, or is there a more
fundamental reason?


Regards


Here is an extreme case
in terms of Beta Pictoris
at many light years distance

arXiv:astro-ph/0601244 v1 11 Jan 2006

Dynamic motions are inferred from
atomic molecular quantum transitions.

The time (frequency) of such transitions are assumed the same
there and here
from which observed differences in frequencies
are related to dynamic motions.

The problem is the same as you identify.
How does one "range" the motions of Asteroid size objects
(which do not have quantum transitions) in Beta Pictoris
other than observing the gross newtonian gravity motions of the system
as a whole.

The problem could be solved if only a radar signal could be sent,
reflected for obtaining active ranging information.

In fact, with the (still functional) Pioneer, the possibility of
obtaining ranging data is enhanced by the fact that it contains a
narrow beam broadcast antenna directed towards the Earth, which can be
turned on and off via ground control.

Whether or not NASA thought to accuirately design and measure such turn
on/off delays prior to launch, in order to facilitate such a ranging
test, is, of course, another matter.

Even when Pioneer 10 and 11 were fully functional (and contact was lost
with 11 in 1995 and 10 in 2003) the fact remains that they couldn't do
the type of ranging involving transmitting and receiving a modulated
signal that was done with Galileo and Ulysses. They certainly wouldn't
have used anything as drastic as turning the transmitter on and off.

Jonathan Silverlight wrote:
In message .com,
"John (Liberty) Bell" writes

Richard Saam wrote:
Oh No wrote:

The position of Pioneer was calculated from Doppler information. Ranging
was not available. Can anyone explain why ranging could not be used? Is
this just a limit on available technology, or is there a more
fundamental reason?


Regards


Here is an extreme case
in terms of Beta Pictoris
at many light years distance

arXiv:astro-ph/0601244 v1 11 Jan 2006

Dynamic motions are inferred from
atomic molecular quantum transitions.

The time (frequency) of such transitions are assumed the same
there and here
from which observed differences in frequencies
are related to dynamic motions.

The problem is the same as you identify.
How does one "range" the motions of Asteroid size objects
(which do not have quantum transitions) in Beta Pictoris
other than observing the gross newtonian gravity motions of the system
as a whole.

The problem could be solved if only a radar signal could be sent,
reflected for obtaining active ranging information.

In fact, with the (still functional) Pioneer, the possibility of
obtaining ranging data is enhanced by the fact that it contains a
narrow beam broadcast antenna directed towards the Earth, which can be
turned on and off via ground control.

Whether or not NASA thought to accuirately design and measure such turn
on/off delays prior to launch, in order to facilitate such a ranging
test, is, of course, another matter.

Even when Pioneer 10 and 11 were fully functional (and contact was lost
with 11 in 1995 and 10 in 2003)

According to Anderson et al. contact was not lost with Pioneer 10. The
transmitter was switched off via ground control to conserve energy,
thereby allowing it to be switched on again at a later date, for
further tests.

the fact remains that they couldn't do
the type of ranging involving transmitting and receiving a modulated
signal that was done with Galileo and Ulysses. They certainly wouldn't
have used anything as drastic as turning the transmitter on and off.

No, but they could now, if they knew switch on/off times accurately, in
order to test whether the unexpected apparent anomalous acceleration
had real consequences in terms of resultant reduced elapsed distance.

John (Liberty) Bell
http://global.accelerators.co.uk
(Change John to Liberty to respond by email)

"John (Liberty) Bell" writes:
Oh No wrote:
The position of Pioneer was calculated from Doppler information.

This statement is misleading. The position(s) of Pioneer(s) at any
given time was calculated using classical trajectory dynamics (with GR
corrections taken into account). So was the anticipated velocity hence
Doppler shift of antenna signal at any given time. What was observed by
NASA/JPL was an accumulating deviation from predicted Doppler shift,
which led Anderson et al. to infer an apparent classically anomalous
acceleration of the probes.

These apparent classically anomalous accelerations were tabulated
against predicted positions, not against altered positions inferred
from such apparent classically anomalous accelerations of the probes.

Your statement is also misleading. While it is true that the
trajectory was "predicted" by classical mechanics, what you don't say
is that the parameters of the trajectory (initial conditions) were
adjusted in order to provide the best possible fit of the model to the
Doppler observations. Thus in a very real sense, the Doppler
observations can be used to "calculate" the position of the Pioneer
spacecraft. Despite the adjustment of all possible classical "knobs"
in the model, the anomaly remains.

CM

Jonathan Silverlight wrote:
In message .com,
"John (Liberty) Bell" writes

Richard Saam wrote:
Oh No wrote:

The position of Pioneer was calculated from Doppler information. Ranging
was not available. Can anyone explain why ranging could not be used? Is
this just a limit on available technology, or is there a more
fundamental reason?


Regards


Here is an extreme case
in terms of Beta Pictoris
at many light years distance

arXiv:astro-ph/0601244 v1 11 Jan 2006

Dynamic motions are inferred from
atomic molecular quantum transitions.

The time (frequency) of such transitions are assumed the same
there and here
from which observed differences in frequencies
are related to dynamic motions.

The problem is the same as you identify.
How does one "range" the motions of Asteroid size objects
(which do not have quantum transitions) in Beta Pictoris
other than observing the gross newtonian gravity motions of the system
as a whole.

The problem could be solved if only a radar signal could be sent,
reflected for obtaining active ranging information.

In fact, with the (still functional) Pioneer, the possibility of
obtaining ranging data is enhanced by the fact that it contains a
narrow beam broadcast antenna directed towards the Earth, which can be
turned on and off via ground control.

Whether or not NASA thought to accuirately design and measure such turn
on/off delays prior to launch, in order to facilitate such a ranging
test, is, of course, another matter.

Even when Pioneer 10 and 11 were fully functional (and contact was lost
with 11 in 1995 and 10 in 2003) the fact remains that they couldn't do
the type of ranging involving transmitting and receiving a modulated
signal that was done with Galileo and Ulysses. They certainly wouldn't
have used anything as drastic as turning the transmitter on and off.

Notwithstanding the fact that Anderson et al. claimed (I think in 2004)
that Pioneer 10 was still functional, with its antenna turned off to
conserve energy, the fact remains that, if their reported apparent
anamolous acceleration is real, this should mean that the effect of
turning the antenna on or off should, by now, be observable on Earth
more than 1 second before originally expected.

Knowledge of the antenna turn on/off times to an accuracy better than
this, is, I suggest, not too much to ask for the adequate pre-launch
documentation of a piece of kit (and space program) of this cost.

Performing such a proposed test is hardly drastic, and far from
expensive (if adequate pre-launch documentation exists), given that
NASA/JPL have already turned off the antenna, and plan on switching it
on again at some unspecified time in the future.

John (Liberty) Bell
http://global.accelerators.co.uk
(Change John to Liberty to respond by email)

Jonathan Silverlight writes

Even when Pioneer 10 and 11 were fully functional (and contact was lost
with 11 in 1995 and 10 in 2003) the fact remains that they couldn't do
the type of ranging involving transmitting and receiving a modulated
signal that was done with Galileo and Ulysses. They certainly wouldn't
have used anything as drastic as turning the transmitter on and off.

Is it the case that these two ought to be able to show the anomalous
pioneer acceleration, or are there too many other confounding influences
for it to be readily isolated?

--
Oz
This post is worth absolutely nothing and is probably fallacious.

In message .com,
"John (Liberty) Bell" writes

Jonathan Silverlight wrote:

Even when Pioneer 10 and 11 were fully functional (and contact was lost
with 11 in 1995 and 10 in 2003) the fact remains that they couldn't do
the type of ranging involving transmitting and receiving a modulated
signal that was done with Galileo and Ulysses. They certainly wouldn't
have used anything as drastic as turning the transmitter on and off.

Notwithstanding the fact that Anderson et al. claimed (I think in 2004)
that Pioneer 10 was still functional, with its antenna turned off to
conserve energy,

Would you like to cite a source for that? Anyway, what do you mean "with
its antenna turned off"? The Pioneers used travelling wave tubes in
their transmitters, and although they were occasionally turned off
everyone was surprised when they were turned on again and still worked
:-)

the fact remains that, if their reported apparent
anamolous acceleration is real, this should mean that the effect of
turning the antenna on or off should, by now, be observable on Earth
more than 1 second before originally expected.

Quite apart from more formal publications, the Pioneer anomaly has been
discussed on Usenet for at least five years
http://groups.google.com/group/sci.p...hread/a88ae76f
f5a0f575/c3f9417441fff44e?lnk=st&q=%22pioneer+anomaly%22+tu ryshev&rnum=1#
c3f9417441fff44e
http://tinyurl.com/pdk47 and it's been established by correspondence
with Slava Turyshev that a simple round-trip time measurement isn't
sufficiently accurate to solve the problem, even if it could be done.
You _have_ done some research on this topic, haven't you?
--
Mail to jsilverlight at the address shown is more likely to be seen!