America's biggest mistake

[George Herold]

On Monday, July 22, 2019 at 3:06:48 PM UTC-4, John Larkin wrote:

On Mon, 22 Jul 2019 10:13:06 -0700 (PDT), George Herold
gherold@teachspin.com> wrote:

On Monday, July 22, 2019 at 10:40:06 AM UTC-4, John Larkin wrote:
On Thu, 18 Jul 2019 19:39:02 -0500, tubeguy@myshop.com wrote:

America's biggest mistake was landing on the moon 50 years ago. This was
the start of satellites, which lead to the cell phones. Now we have a
generation of idiot "cell tards". (Kids addicted to cellphones who have
no real lives).


That was an expensive mistake, but it didn't create satellites. It
actually didn't create much of anything.

America's biggest mistake was slavery.
I'll agree with that!

Re: Apollo, I read in the paper that for a few years we were spending
something like 2% of GDP on the moon program. (I had no idea it was
that big.)


NASA's budget is now 21 billion. We could do some serious space
science and aeronautics if we canned the absurd manned flight
programs.

Yup, I'd love to see a mission that sent a robot sub out to which
ever of Jupiter's moons has water inside. (I guess that's
Europa)
https://en.wikipedia.org/wiki/Europa_(moon)


It seems like the pace of technological change has slowed down.
(well expect for computers/ Moore's law.) 50 years since the moon shot
and how much different are rockets today? (except for 'puters inside.)
or my car, or washing machine... etc.
George H.

--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

On Monday, 22 July 2019 11:24:09 UTC+1, Clifford Heath wrote:

On 22/7/19 6:24 pm, Bill Sloman wrote:

You really are one dumb offensive idiot.

There is only one solution. Plonk him.

 

[Clifford Heath]

On 23/7/19 3:13 am, George Herold wrote:

On Monday, July 22, 2019 at 10:40:06 AM UTC-4, John Larkin wrote:
On Thu, 18 Jul 2019 19:39:02 -0500, tubeguy@myshop.com wrote:

America's biggest mistake was landing on the moon 50 years ago. This was
the start of satellites, which lead to the cell phones. Now we have a
generation of idiot "cell tards". (Kids addicted to cellphones who have
no real lives).

That was an expensive mistake, but it didn't create satellites. It
actually didn't create much of anything.

America's biggest mistake was slavery.
I'll agree with that!

America's biggest mistake was not to repulse the white European invaders.

Re: Apollo, I read in the paper that for a few years we were spending
something like 2% of GDP on the moon program. (I had no idea it was
that big.)

We were told it peaked about 4%. The 400,000 people involved was about
2% of the population. No wonder there was social unrest.

Clifford Heath.

 

[Clifford Heath]

On 23/7/19 3:52 am, upsidedown@downunder.com wrote:

On Mon, 22 Jul 2019 17:45:16 +1000, Clifford Heath
no.spam@please.net> wrote:

On 22/7/19 3:15 pm, upsidedown@downunder.com wrote:
On Mon, 22 Jul 2019 11:03:30 +1000, Clifford Heath
no.spam@please.net> wrote:
And GPS is just the Apollo ranging system (which I described in another
thread today), turned upside-down, with relativistic calculations to
locate the birds, and triangulation to compute the position.

The ranging system used in Apollo is now known as two way ranging and
is used in all planetary probes these days.

While GPS also uses PRN codes, it is essentially a one way system.
They didn't have an atomic clock on the Apollo, nor a ground computer
capable of the relativistic calculations needed.

You do not need an atomic clock nor relativistic corrections to use
two-way ranging.

That's my point. GPS is built on accurate ranging that was developed
during Apollo. I never said it didn't need more to make it work, just
that it extended that. Do you disagree?

The only requirement is that you have a stable clock
from the transmission to reception. For lunar missions, the clocks
needed to be stable for about 2.5 s, for Voyagers a one day stable
period is required.

With 5.5 MHz PRN chip clock, the length of one chip is 54 meter. To
get decimeter accuracy you need to be able to measure the phase
difference between Tx and Rx chip pulse to an accuracy about 1 degree,
which requires a quite good SNR.

Apollo used a 992KHz clock, but it must have had <1ns jitter. The phase
modulation was directly applied to the S-band carrier (~2GHz), and the
receiver was able to resolve to just a few cycles of that carrier.

You do not want to cancel doppler, since you want to measure it to
determine the radial speed.

I said the wrong thing. Synthesising Tx from Rx signals doubles the
Doppler effect. On approach, the receiver sees a higher frequency, so
the transmitter sends a higher frequency, which is further compressed by
return Doppler. The radial speed (from ranging) could be used to
separate Doppler shifts from oscillator drift.

Now you have the absolute distance using
the PRN code and radial velocity from doppler and using orbital
mechanics, you can quite accurately calculate the current and
predicted position without knowing the sideway position or tangential
velocity.

Right - brilliant stuff! I think you get the departure hyperbola, but
not the lateral (3rd) dimension though. Not sure how they got that, but
it's less important.

When A13 fired for TEI they had to guess somewhat at the spacecraft mass
(not knowing what was left after the explosion), and had over-estimated
it, so it wound up aimed at the Indian ocean instead of the south
Atlantic as they'd hoped. Stan Anderson was given four days to get his
"Snoopy" tracking planes into the area to sight the splashdown, which
was more than enough time. The incidence angle was dangerously low at
2.6 degrees; anything below 3 degrees risked bouncing off, but it worked
out ok. Stan talked about all this with us over the last weekend.

Clifford Heath.

 

[Bill Sloman]

On Tuesday, July 23, 2019 at 10:15:11 AM UTC+10, Clifford Heath wrote:

On 23/7/19 3:52 am, upsidedown@downunder.com wrote:
On Mon, 22 Jul 2019 17:45:16 +1000, Clifford Heath
no.spam@please.net> wrote:

On 22/7/19 3:15 pm, upsidedown@downunder.com wrote:
On Mon, 22 Jul 2019 11:03:30 +1000, Clifford Heath
no.spam@please.net> wrote:
And GPS is just the Apollo ranging system (which I described in another
thread today), turned upside-down, with relativistic calculations to
locate the birds, and triangulation to compute the position.

The ranging system used in Apollo is now known as two way ranging and
is used in all planetary probes these days.

While GPS also uses PRN codes, it is essentially a one way system.
They didn't have an atomic clock on the Apollo, nor a ground computer
capable of the relativistic calculations needed.

You do not need an atomic clock nor relativistic corrections to use
two-way ranging.

That's my point. GPS is built on accurate ranging that was developed
during Apollo. I never said it didn't need more to make it work, just
that it extended that. Do you disagree?

The Wikipedia history of GPS doesn't say a word about the Apollo ranging system, and says quite a lot about Loran, Decca Navigator, TRANSIT, OMEGA and SECOR.

https://en.wikipedia.org/wiki/Global_Positioning_System

There really isn't any way in which GPS can be seen as an extension of the Apollo ranging system.

<snip>

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Tuesday, July 23, 2019 at 10:40:59 AM UTC+10, tabb...@gmail.com wrote:

On Monday, 22 July 2019 11:24:09 UTC+1, Clifford Heath wrote:
On 22/7/19 6:24 pm, Bill Sloman wrote:

You really are one dumb offensive idiot.

There is only one solution. Plonk him.

NT does recommend ignoring anybody who has the temerity to disagree with you.

Like most of the people who go in for plonking, he does have a lot of silly ideas which richly deserve all the jeering that gets directed at them, and seems to lack the capacity to realise that he really is posting dangerous nonsense.

Granting that, plonking is the only solution that works for him. Adopting it would put you in bad company.

--
Bill Sloman, Sydney

 

[Clifford Heath]

On 23/7/19 12:55 pm, Bill Sloman wrote:

On Tuesday, July 23, 2019 at 10:15:11 AM UTC+10, Clifford Heath wrote:
On 23/7/19 3:52 am, upsidedown@downunder.com wrote:
On Mon, 22 Jul 2019 17:45:16 +1000, Clifford Heath
no.spam@please.net> wrote:

On 22/7/19 3:15 pm, upsidedown@downunder.com wrote:
On Mon, 22 Jul 2019 11:03:30 +1000, Clifford Heath
no.spam@please.net> wrote:
And GPS is just the Apollo ranging system (which I described in another
thread today), turned upside-down, with relativistic calculations to
locate the birds, and triangulation to compute the position.

The ranging system used in Apollo is now known as two way ranging and
is used in all planetary probes these days.

While GPS also uses PRN codes, it is essentially a one way system.
They didn't have an atomic clock on the Apollo, nor a ground computer
capable of the relativistic calculations needed.

You do not need an atomic clock nor relativistic corrections to use
two-way ranging.

That's my point. GPS is built on accurate ranging that was developed
during Apollo. I never said it didn't need more to make it work, just
that it extended that. Do you disagree?

The Wikipedia history of GPS doesn't say a word about the Apollo ranging system, and says quite a lot about Loran, Decca Navigator, TRANSIT, OMEGA and SECOR.

https://en.wikipedia.org/wiki/Global_Positioning_System

There really isn't any way in which GPS can be seen as an extension of the Apollo ranging system.

The people who *built and operated* Apollo disagree with you. I know
this - I was talking face to face with some of them just this weekend.

Just stop displaying your ignorance, Bill, you're out of your depth and
apparently know nothing that you can't find in Wikipedia.

Clifford Heath.

 

On Tue, 23 Jul 2019 10:15:04 +1000, Clifford Heath
<no.spam@please.net> wrote:

On 23/7/19 3:52 am, upsidedown@downunder.com wrote:
On Mon, 22 Jul 2019 17:45:16 +1000, Clifford Heath
no.spam@please.net> wrote:

On 22/7/19 3:15 pm, upsidedown@downunder.com wrote:
On Mon, 22 Jul 2019 11:03:30 +1000, Clifford Heath
no.spam@please.net> wrote:
And GPS is just the Apollo ranging system (which I described in another
thread today), turned upside-down, with relativistic calculations to
locate the birds, and triangulation to compute the position.

The ranging system used in Apollo is now known as two way ranging and
is used in all planetary probes these days.

While GPS also uses PRN codes, it is essentially a one way system.
They didn't have an atomic clock on the Apollo, nor a ground computer
capable of the relativistic calculations needed.

You do not need an atomic clock nor relativistic corrections to use
two-way ranging.

That's my point. GPS is built on accurate ranging that was developed
during Apollo. I never said it didn't need more to make it work, just
that it extended that. Do you disagree?

The only requirement is that you have a stable clock
from the transmission to reception. For lunar missions, the clocks
needed to be stable for about 2.5 s, for Voyagers a one day stable
period is required.

With 5.5 MHz PRN chip clock, the length of one chip is 54 meter. To
get decimeter accuracy you need to be able to measure the phase
difference between Tx and Rx chip pulse to an accuracy about 1 degree,
which requires a quite good SNR.

Apollo used a 992KHz clock, but it must have had <1ns jitter. The phase
modulation was directly applied to the S-band carrier (~2GHz), and the
receiver was able to resolve to just a few cycles of that carrier.

You do not want to cancel doppler, since you want to measure it to
determine the radial speed.

I said the wrong thing. Synthesising Tx from Rx signals doubles the
Doppler effect. On approach, the receiver sees a higher frequency, so
the transmitter sends a higher frequency, which is further compressed by
return Doppler. The radial speed (from ranging) could be used to
separate Doppler shifts from oscillator drift.

Now you have the absolute distance using
the PRN code and radial velocity from doppler and using orbital
mechanics, you can quite accurately calculate the current and
predicted position without knowing the sideway position or tangential
velocity.

Right - brilliant stuff! I think you get the departure hyperbola, but
not the lateral (3rd) dimension though. Not sure how they got that, but
it's less important.

With extremely accurate distance and velocity (doppler) measurements
combined with the less accurate six classical orbital elements
obtained by other means, you can improve the accuracy after a few
orbits.

If you know the inclination, this limits the north-south range where
the satellite could be. Measuring the minimum distance to tracking
station or doppler zero on two or more orbits, you can calculate the
orbit period and from this the orbit size (if the mass of the big body
is known). If eccentricity is known, you can calculate the perigeum
and apogeum of the orbit. If you had measured one of these by some
means, you can calculate the eccentricity. With the other classical
parameters, you can fully describe th orbit in relation to the sky.

With some highly accurate distance and speed measurements, you can
then gradually refine these classical parameters and hence predict the
orbit in the future (extrapolating).

Of course a GPS satellite also broadcasts its orbit parameters with a
very high accuracy, but these parameters are uploaded to the GPS
satellite by the tracking station. These must be updated periodically
to include orbital variations.

When A13 fired for TEI they had to guess somewhat at the spacecraft mass
(not knowing what was left after the explosion), and had over-estimated
it, so it wound up aimed at the Indian ocean instead of the south
Atlantic as they'd hoped. Stan Anderson was given four days to get his
"Snoopy" tracking planes into the area to sight the splashdown, which
was more than enough time. The incidence angle was dangerously low at
2.6 degrees; anything below 3 degrees risked bouncing off, but it worked
out ok. Stan talked about all this with us over the last weekend.

Clifford Heath.

 

[Bill Sloman]

On Tuesday, July 23, 2019 at 2:28:14 PM UTC+10, Clifford Heath wrote:

On 23/7/19 12:55 pm, Bill Sloman wrote:
On Tuesday, July 23, 2019 at 10:15:11 AM UTC+10, Clifford Heath wrote:
On 23/7/19 3:52 am, upsidedown@downunder.com wrote:
On Mon, 22 Jul 2019 17:45:16 +1000, Clifford Heath
no.spam@please.net> wrote:

On 22/7/19 3:15 pm, upsidedown@downunder.com wrote:
On Mon, 22 Jul 2019 11:03:30 +1000, Clifford Heath
no.spam@please.net> wrote:
And GPS is just the Apollo ranging system (which I described in another
thread today), turned upside-down, with relativistic calculations to
locate the birds, and triangulation to compute the position.

The ranging system used in Apollo is now known as two way ranging and
is used in all planetary probes these days.

While GPS also uses PRN codes, it is essentially a one way system.
They didn't have an atomic clock on the Apollo, nor a ground computer
capable of the relativistic calculations needed.

You do not need an atomic clock nor relativistic corrections to use
two-way ranging.

That's my point. GPS is built on accurate ranging that was developed
during Apollo. I never said it didn't need more to make it work, just
that it extended that. Do you disagree?

The Wikipedia history of GPS doesn't say a word about the Apollo ranging system, and says quite a lot about Loran, Decca Navigator, TRANSIT, OMEGA and SECOR.

https://en.wikipedia.org/wiki/Global_Positioning_System

There really isn't any way in which GPS can be seen as an extension of the Apollo ranging system.

The people who *built and operated* Apollo disagree with you. I know
this - I was talking face to face with some of them just this weekend.

The people who built and operated Apollo do have a particular interest in seeing is as the source and fount of everything built since then. Quite how many of them you'd run into in Australia is an interesting question. The guys who worked at Honeysuckle Creek weren't exactly the designers.

Just stop displaying your ignorance, Bill, you're out of your depth and
apparently know nothing that you can't find in Wikipedia.

Grow up. Wikipedia is a easily accessible source of what everybody could know with minimum effort - the kind of effort you don't seem to have put in.

For a slightly less shallow piece of insight see pages 6-10 of the NSW IEEE newsletter, which I happen to edit

http://sites.ieee.org/nsw/files/2019/07/Circuit_July_2019v1.pdf

Nothing about the Apollo ranging system, but it does make it clear how Honeysuckle Creek was involved with the Apollo mission, and how little the guys who worked there needed to know about the ranging system.

--
Bill Sloman, Sydney

 

[Clifford Heath]

On 23/7/19 5:23 pm, Bill Sloman wrote:

For a slightly less shallow piece of insight see pages 6-10 of the NSW IEEE newsletter, which I happen to edit
http://sites.ieee.org/nsw/files/2019/07/Circuit_July_2019v1.pdf

Further enshrining CSIRO's long-standing prevarication? It's only this
last week that John Sarkissian finally came clean. Parkes must have been
very bitter it wasn't them who got the first steps. But then they had no
transmit capability, so could not send ranging, could not decode the
telemetry (that was sent to HSK as a backup), and had various other
comms weaknesses - they were always peripheral to the moon landing - if
the video camera hadn't been included at the last minute, their
involvement would barely be remembered. But that's enough to dupe the
IEEE apparently.

> Nothing about the Apollo ranging system, but it does make it clear how Honeysuckle Creek was involved with the Apollo mission, and how little the guys who worked there needed to know about the ranging system.

I could give you phone numbers and email addresses of Keith Brockelsby
and Bernard Smith, both of whom still have the engineering documentation
and both of whom separately related to me *in detail* exactly how the
system worked - and that's fifty years after it happened - PRNG sequence
lengths, frequencies, correlation method, everything. But I wouldn't
allow you to waste their time.

End. I won't argue this with you any further.

Clifford Heath.

 

[Bill Sloman]

On Tuesday, July 23, 2019 at 5:43:47 PM UTC+10, Clifford Heath wrote:

On 23/7/19 5:23 pm, Bill Sloman wrote:
For a slightly less shallow piece of insight see pages 6-10 of the NSW IEEE newsletter, which I happen to edit
http://sites.ieee.org/nsw/files/2019/07/Circuit_July_2019v1.pdf

Further enshrining CSIRO's long-standing prevarication? It's only this
last week that John Sarkissian finally came clean. Parkes must have been
very bitter it wasn't them who got the first steps.

Why?

But then they had no
transmit capability, so could not send ranging, could not decode the
telemetry (that was sent to HSK as a backup), and had various other
comms weaknesses - they were always peripheral to the moon landing - if
the video camera hadn't been included at the last minute, their
involvement would barely be remembered. But that's enough to dupe the
IEEE apparently.

Bigger antenna meant a better signal to noise ratio so what they received was what was passed on, at least for the bulk of the transmission.

It was - first and foremost - a radio telescope which is why it's still there and still working.

Nothing about the Apollo ranging system, but it does make it clear how Honeysuckle Creek was involved with the Apollo mission, and how little the guys who worked there needed to know about the ranging system.

I could give you phone numbers and email addresses of Keith Brockelsby
and Bernard Smith, both of whom still have the engineering documentation
and both of whom separately related to me *in detail* exactly how the
system worked - and that's fifty years after it happened - PRNG sequence
lengths, frequencies, correlation method, everything. But I wouldn't
allow you to waste their time.

None of which has anything much to do with GPS, so why would I want to waste their time?

> End. I won't argue this with you any further.

Wise decision. The more you post, the more obvious it is that you don't know enough about what you are talking about.

--
Bill Sloman, Sydney

 

On Tuesday, 23 July 2019 05:28:14 UTC+1, Clifford Heath wrote:

The people who *built and operated* Apollo disagree with you. I know
this - I was talking face to face with some of them just this weekend.

Just stop displaying your ignorance, Bill, you're out of your depth and
apparently know nothing that you can't find in Wikipedia.

Honestly, that's never going to happen

 

[Clifford Heath]

On 23/7/19 5:26 pm, upsidedown@downunder.com wrote:

On Tue, 23 Jul 2019 10:15:04 +1000, Clifford Heath
no.spam@please.net> wrote:

On 23/7/19 3:52 am, upsidedown@downunder.com wrote:
On Mon, 22 Jul 2019 17:45:16 +1000, Clifford Heath
no.spam@please.net> wrote:

On 22/7/19 3:15 pm, upsidedown@downunder.com wrote:
On Mon, 22 Jul 2019 11:03:30 +1000, Clifford Heath
no.spam@please.net> wrote:
And GPS is just the Apollo ranging system (which I described in another
thread today), turned upside-down, with relativistic calculations to
locate the birds, and triangulation to compute the position.

The ranging system used in Apollo is now known as two way ranging and
is used in all planetary probes these days.

While GPS also uses PRN codes, it is essentially a one way system.
They didn't have an atomic clock on the Apollo, nor a ground computer
capable of the relativistic calculations needed.

You do not need an atomic clock nor relativistic corrections to use
two-way ranging.

That's my point. GPS is built on accurate ranging that was developed
during Apollo. I never said it didn't need more to make it work, just
that it extended that. Do you disagree?

The only requirement is that you have a stable clock
from the transmission to reception. For lunar missions, the clocks
needed to be stable for about 2.5 s, for Voyagers a one day stable
period is required.

With 5.5 MHz PRN chip clock, the length of one chip is 54 meter. To
get decimeter accuracy you need to be able to measure the phase
difference between Tx and Rx chip pulse to an accuracy about 1 degree,
which requires a quite good SNR.

Apollo used a 992KHz clock, but it must have had <1ns jitter. The phase
modulation was directly applied to the S-band carrier (~2GHz), and the
receiver was able to resolve to just a few cycles of that carrier.

You do not want to cancel doppler, since you want to measure it to
determine the radial speed.

I said the wrong thing. Synthesising Tx from Rx signals doubles the
Doppler effect. On approach, the receiver sees a higher frequency, so
the transmitter sends a higher frequency, which is further compressed by
return Doppler. The radial speed (from ranging) could be used to
separate Doppler shifts from oscillator drift.

Now you have the absolute distance using
the PRN code and radial velocity from doppler and using orbital
mechanics, you can quite accurately calculate the current and
predicted position without knowing the sideway position or tangential
velocity.

Right - brilliant stuff! I think you get the departure hyperbola, but
not the lateral (3rd) dimension though. Not sure how they got that, but
it's less important.

With extremely accurate distance and velocity (doppler) measurements
combined with the less accurate six classical orbital elements
obtained by other means, you can improve the accuracy after a few
orbits.

They did TLI after 3-4 orbits only, and TEI even sooner - yet hit the
earth's atmosphere at the right angle very precisely. I'm in awe,
especially the return trip.

If you know the inclination, this limits the north-south range where
the satellite could be. Measuring the minimum distance to tracking
station or doppler zero on two or more orbits, you can calculate the
orbit period and from this the orbit size (if the mass of the big body
is known). If eccentricity is known, you can calculate the perigeum
and apogeum of the orbit. If you had measured one of these by some
means, you can calculate the eccentricity. With the other classical
parameters, you can fully describe the orbit in relation to the sky.

With some highly accurate distance and speed measurements, you can
then gradually refine these classical parameters and hence predict the
orbit in the future (extrapolating).

Great stuff. A lot of that pertains to earth orbit of course; but the
TEI burn left lunar orbit. Bloody good effort, I say!

Of course a GPS satellite also broadcasts its orbit parameters with a
very high accuracy, but these parameters are uploaded to the GPS
satellite by the tracking station. These must be updated periodically
to include orbital variations.

 

[Bill Sloman]

On Tuesday, July 23, 2019 at 5:48:47 PM UTC+10, tabb...@gmail.com wrote:

On Tuesday, 23 July 2019 05:28:14 UTC+1, Clifford Heath wrote:

The people who *built and operated* Apollo disagree with you. I know
this - I was talking face to face with some of them just this weekend.

Just stop displaying your ignorance, Bill, you're out of your depth and
apparently know nothing that you can't find in Wikipedia.

Honestly, that's never going to happen

The proposition that not agreeing with an under-informed poster is "displaying ignorance" is the kind of rationalisation that under-informed posters do seem to find comforting.

We seem to have two of them here.

--
Bill Sloman, Sydney

 

On Tue, 23 Jul 2019 17:46:49 +1000, Clifford Heath
<no.spam@please.net> wrote:

On 23/7/19 5:26 pm, upsidedown@downunder.com wrote:
On Tue, 23 Jul 2019 10:15:04 +1000, Clifford Heath
no.spam@please.net> wrote:

On 23/7/19 3:52 am, upsidedown@downunder.com wrote:
On Mon, 22 Jul 2019 17:45:16 +1000, Clifford Heath
no.spam@please.net> wrote:

On 22/7/19 3:15 pm, upsidedown@downunder.com wrote:
On Mon, 22 Jul 2019 11:03:30 +1000, Clifford Heath
no.spam@please.net> wrote:
And GPS is just the Apollo ranging system (which I described in another
thread today), turned upside-down, with relativistic calculations to
locate the birds, and triangulation to compute the position.

The ranging system used in Apollo is now known as two way ranging and
is used in all planetary probes these days.

While GPS also uses PRN codes, it is essentially a one way system.
They didn't have an atomic clock on the Apollo, nor a ground computer
capable of the relativistic calculations needed.

You do not need an atomic clock nor relativistic corrections to use
two-way ranging.

That's my point. GPS is built on accurate ranging that was developed
during Apollo. I never said it didn't need more to make it work, just
that it extended that. Do you disagree?

The only requirement is that you have a stable clock
from the transmission to reception. For lunar missions, the clocks
needed to be stable for about 2.5 s, for Voyagers a one day stable
period is required.

With 5.5 MHz PRN chip clock, the length of one chip is 54 meter. To
get decimeter accuracy you need to be able to measure the phase
difference between Tx and Rx chip pulse to an accuracy about 1 degree,
which requires a quite good SNR.

Apollo used a 992KHz clock, but it must have had <1ns jitter. The phase
modulation was directly applied to the S-band carrier (~2GHz), and the
receiver was able to resolve to just a few cycles of that carrier.

You do not want to cancel doppler, since you want to measure it to
determine the radial speed.

I said the wrong thing. Synthesising Tx from Rx signals doubles the
Doppler effect. On approach, the receiver sees a higher frequency, so
the transmitter sends a higher frequency, which is further compressed by
return Doppler. The radial speed (from ranging) could be used to
separate Doppler shifts from oscillator drift.

Now you have the absolute distance using
the PRN code and radial velocity from doppler and using orbital
mechanics, you can quite accurately calculate the current and
predicted position without knowing the sideway position or tangential
velocity.

Right - brilliant stuff! I think you get the departure hyperbola, but
not the lateral (3rd) dimension though. Not sure how they got that, but
it's less important.

With extremely accurate distance and velocity (doppler) measurements
combined with the less accurate six classical orbital elements
obtained by other means, you can improve the accuracy after a few
orbits.

They did TLI after 3-4 orbits only, and TEI even sooner - yet hit the
earth's atmosphere at the right angle very precisely. I'm in awe,
especially the return trip.

It was initially designed to use start navigation as the main
navigation method. At some stage, the two-way ranging was added as an
auxiliary method. I have no idea which was the dominant method at the
end of Apollo program.

If you know the inclination, this limits the north-south range where
the satellite could be. Measuring the minimum distance to tracking
station or doppler zero on two or more orbits, you can calculate the
orbit period and from this the orbit size (if the mass of the big body
is known). If eccentricity is known, you can calculate the perigeum
and apogeum of the orbit. If you had measured one of these by some
means, you can calculate the eccentricity. With the other classical
parameters, you can fully describe the orbit in relation to the sky.

With some highly accurate distance and speed measurements, you can
then gradually refine these classical parameters and hence predict the
orbit in the future (extrapolating).


Great stuff. A lot of that pertains to earth orbit of course; but the
TEI burn left lunar orbit. Bloody good effort, I say!


Of course a GPS satellite also broadcasts its orbit parameters with a
very high accuracy, but these parameters are uploaded to the GPS
satellite by the tracking station. These must be updated periodically
to include orbital variations.

 

trader4@optonline.net wrote in
news:dd1c3537-ccea-4f2e-8925-40faf6a49537@googlegroups.com:

On Monday, July 22, 2019 at 12:11:58 AM UTC-4,
DecadentLinux...@decadence.org wrote:
trader4@optonline.net wrote in news:b7441221-ca6f-4855-9876-
6a8ca887ce95@googlegroups.com:

Yet they had a solid state computer in 1953.

Apples and oranges.

There are no 2 ton computers on any spacecraft.

The IC chip made it possible to make a computer small enough to
be
part of the payload of a spacecraft.

Wrong again. There were two competing design proposals for the
Apollo guidance computer. One was developed at Draper Labs, based
on NOR gate ICs. The other was an IBM proposal using discrete
semiconductor technology, similar to what went into military ICBMs
and the Saturn V. It was close, the IBM design had the advantage
that it was proven and no one was saying that it could not work.
NASA decided to go with the Draper design.

It was built by Raytheon. Just like I said it was.
Weight was a MAIN consideration as it has always been with every
space vehicle.

> Wrong, always wrong.

Your sig needs no work. It matches you perfectly.

 

George Herold <gherold@teachspin.com> wrote in
news:90260e5e-81e1-4f9e-93ba-4fd249e7417d@googlegroups.com:

On Monday, July 22, 2019 at 3:06:48 PM UTC-4, John Larkin wrote:
On Mon, 22 Jul 2019 10:13:06 -0700 (PDT), George Herold
gherold@teachspin.com> wrote:

On Monday, July 22, 2019 at 10:40:06 AM UTC-4, John Larkin
wrote:
On Thu, 18 Jul 2019 19:39:02 -0500, tubeguy@myshop.com wrote:

America's biggest mistake was landing on the moon 50 years
ago. This was the start of satellites, which lead to the cell
phones. Now we have a generation of idiot "cell tards". (Kids
addicted to cellphones who have no real lives).


That was an expensive mistake, but it didn't create
satellites. It actually didn't create much of anything.

America's biggest mistake was slavery.
I'll agree with that!

Re: Apollo, I read in the paper that for a few years we were
spending something like 2% of GDP on the moon program. (I had
no idea it was that big.)


NASA's budget is now 21 billion. We could do some serious space
science and aeronautics if we canned the absurd manned flight
programs.
Yup, I'd love to see a mission that sent a robot sub out to which
ever of Jupiter's moons has water inside. (I guess that's
Europa)
https://en.wikipedia.org/wiki/Europa_(moon)


It seems like the pace of technological change has slowed down.
(well expect for computers/ Moore's law.) 50 years since the moon
shot and how much different are rockets today? (except for 'puters
inside.) or my car, or washing machine... etc.
George H.

<https://royal.pingdom.com/the-single-atom-transistor-is-here-the-
amazing-evolution-of-microprocessors-infographic/>

<https://tinyurl.com/yyafjdwv>

 

John Larkin <jjlarkin@highland_snip_technology.com> wrote in
news:h12cjehoob584530v8aj1jctbbhmu84ksa@4ax.com:

NASA's budget is now 21 billion. We could do some serious space
science and aeronautics if we canned the absurd manned flight
programs.

We ARE doing serious space science. That is what the ISS is for.

You have serious problems and it is you being absurd.

 

trader4@optonline.net wrote in news:37cefb4e-d7da-4eac-bcfd-
022770bcb63e@googlegroups.com:

When you have a link that goes back to a source, we can check that
out and maybe see if it's true or another exaggeration.

You are a goddamned retard.

 

trader4@optonline.net wrote in
news:8aab75f2-8ca1-4ba9-8786-0a2ff99cb9ad@googlegroups.com:

On Monday, July 22, 2019 at 11:11:51 AM UTC-4,
DecadentLinux...@decadence.org wrote:
trader4@optonline.net wrote in
news:d75ce3b1-7916-4d51-bde0-9635d1eb87be@googlegroups.com:

On Monday, July 22, 2019 at 12:15:27 AM UTC-4,
DecadentLinux...@decadence.org wrote:
trader4@optonline.net wrote in
news:b7441221-ca6f-4855-9876-6a8ca887ce95@googlegroups.com:

IBM was using transistors, the iconic 360 line was
introduced in 1964, 5 years before the moon landing and
obviously IBM was working on the 360 for years before that.
So was Sperry Rand:

You are about as stupid as it gets.

Mainframes computers back then had no ICs in them because
the ICs
did not exist yet.

I did not say that any computers had ICs in them at the time
the US started the Apollo program. However you posted this
whopper:

"IBM was using tubes and that was not going to cut it on the
moon."


It is true.

No, it's a lie. At the time the Apollo program began, new
computers had been using transistors, not tubes, for a long time.
Companies like IBM, Sperry Rand, DEC....

So what, you fucking idiot? They were also STILL using the tube
based machines. Get a clue, dumbfuck.

A heavy computer was not an option. Wake the fuck up.

No shit Sherlock. So why did you bring up tubes when computers
for everything from commercial application to military were
already using transistors?

Yes... using transistors in computers that STILL took up entire
rows of racks full of gear. WAKE UP. And they were also STILL using
tube hardware as well. Entire floors of buildings and environmental
controls were required.

You brought it up because you're
wrong, always wrong.

You are blind because of your lame obsessions and this is one of
them.

Oh and that included the current crop of 'solid state' versions
back then.


That's a lie as evidenced by the use of discrete transistor
computers for the Titan ICBMs and the Saturn V guidance systems.

Even the missiles that did end up with IC chips still had huge
discrete wired sections. The mercury program used the Titan II.
Guess what guidance chips it incorporated?

You are truly clueless.

You do a good job of googling but only prove you have no
actual
been around to see it knowledge.

You are a fat assed punk, at best. I doubt that you are
even 30
years old. Your eleven year old mental age is sure glaring.


This from the guy who posted:

"IBM was using tubes and that was not going to cut it on the
moon."


You get hung up on stupid shit and think it makes you look
smart.
You fail, child.

It was your stupidity, not mine or anyone else here. Even your
butt buddy Bill has told you that you're wrong.

"butt buddy"? You do know that if I tried, I could easily find
you, right?

Guess what you'll end up with shoved up your ass. I'll give you a
int as to what, so you can google it.

It is an overbore of 0.80 inches.

In fact IBM, Sperry Rand, DEC, etc were producing computers
using transistors when the Apollo program started.

Room sized business computers were not an option. You need to
wake
the fuck up, child.

Not just larger business computers, but also the computers for the
Titan and Saturn V guidance systems, designed and supplied by IBM.

You are clueless.

And there were two
different concepts for the Apollo guidance computer at the
time, one using ICs the other an IBM design using discrete
components.

There were more players considered than just those, dipshit.

Sure, a few posts ago you thought computers were still using
vacuum tubes at the start of the Apollo program. So much for
who's the dipshit, dipshit.

I did not "think" anything. Tube based computers, as well as the
newer machines were used. They did not design themselves, dipshit.

The two were evaluated and hotly debated.

Oh boy! "hotly debated"! Wow.


No one was saying the
IBM design could not be used,

Plenty were. In fact they got tossed early on.

That's a lie, which is why you can't supply any names or
specifics, while I can.

The Mercury mission was atop an Atlas rocket.

The Gemini missions were atop Titan II specials.
That bird has an IC chip in it. Not from IBM.

in fact it was favored by many
because it was a proven design,

Not for mission guidance it wasn't.

It was proven capable and reliable for guiding the Titan ICBM.

And got tossed with the advent of the Titan II. Ooops.

And it was chosen and used in the Saturn V, dipshit. Both were
IBM supplied, using discrete semiconductors. (not vacuum tubes)

I have seen (military) tubes smaller than a pinky finger.

while ICs were new and uncertain.

ICs were non existent and were custom made for the purpose.

Wrong again, always wrong. Kilby and Noyce had both
independently built the first ICs in 1959.

As if I need a primer on it from a fat assed google dope like you.

In 1960 TI and
Fairchild had already announced their first commercial ICs. The
Apollo program didn't start until 1961.

You really are clueless about how things happen in the science
community.

http://www.wylie.org.uk/technology/computer/ICs/monolith/monolith.h
tm

Since TI and Fairchild were the co-inventors of the IC, you might
expect that they would release the first commercial devices, and
in fact this was so. In some places on the Web the Fairchild 900
series is credited with being the first to market, in 1961, but
the documented evidence does not support that: the Chip Collection
gives a very specific date of March 1960 and price for the first
announced TI chip, the SN502, and Khambata states unequivocally
that "In 1960, Texas Instruments announced the introduction of the
earliest product line of integrated logic circuits. TI's trade
name is 'Solid Circuits' for this line. This family, called the
series 51, utilized the modified DCTL circuit...". Finally,
"Electronic Design" magazine announced the Texas devices in March
1960,and Fairchild prototype chips in November 1960.

You really are clueless about military funding and programs.

> Wrong, always wrong.

Your sig fits you perfectly though. Funny that you are blind to
it.