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CX2SA > SATDIG 17.03.14 20:30l 961 Lines 34086 Bytes #999 (0) @ WW
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From: CX2SA@CX2SA.SAL.URY.SA
To : SATDIG@WW
Today's Topics:
1. Rocket Man (Les Rayburn)
2. Reducing Orbital Debris From Batteries (B J)
3. Re: Malaysian airliner puzzle (Michael Chen)
4. Re: Malaysian airliner puzzle (Tom Busch)
5. Re: Malaysian airliner puzzle (Tom Busch)
6. Re: Malaysian airliner puzzle (Nitin Muttin)
7. Re: Malaysian airliner puzzle (Chandler Heath)
8. Re: Malaysian airliner puzzle (Joe)
9. Re: Malaysian airliner puzzle (Nitin Muttin)
10. Re: Malaysian airliner puzzle (Tom Busch)
----------------------------------------------------------------------
Message: 1
Date: Mon, 17 Mar 2014 01:23:53 -0500
From: Les Rayburn <les@xxxxxxxxxxxx.xxx>
To: AMSAT Mailing List <amsat-bb@xxxxx.xxx>, Star-Com BB
<starcom-bb@xxxxxxxx.xxx>
Subject: [amsat-bb] Rocket Man
Message-ID: <532694F9.5000901@xxxxxxxxxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
One of most pleasant experiences that a satellite operator could ever
have, occurred for me this weekend. Saturday night, sitting third row
center, only ten feet from the stage. Listening to Elton John sing
"Rocket Man" with my beautiful XYL at my side.
For a lifelong space enthusiast, and amateur satellite operator, it
doesn't get much better than that!
--
--
73,
Les Rayburn, N1LF
121 Mayfair Park
Maylene, AL 35114
EM63nf
6M VUCC #1712
AMSAT #38965
Grid Bandits #222
Southeastern VHF Society
Central States VHF Society Life Member
Six Club #2484
Active on 6 Meters thru 1296, 10GHz & Light
------------------------------
Message: 2
Date: Mon, 17 Mar 2014 14:54:50 +0000
From: B J <va6bmj@xxxxx.xxx>
To: amsat-bb <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Reducing Orbital Debris From Batteries
Message-ID:
<CAP7QzkMH7qo7bvBq5OXLNsgpDfrquG8SbrtK8mdYr8c+T4MP1A@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
http://www.parabolicarc.com/2014/03/17/esa-reduce-debris-threat-batteries/
73s
Bernhard VA6BMJ @ DO33FL
------------------------------
Message: 3
Date: Mon, 17 Mar 2014 23:05:15 +0800
From: Michael Chen <michael.bd5rv@xxxxx.xxx>
To: amsat-bb <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: Malaysian airliner puzzle
Message-ID:
<CAAqnEHX0FdSnmoj=uhD-d+91gZS06FAzcdyEXvXPeDy5O68HHw@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
The distance calculated between the satellite and the plane won't be
credible if the time on both are not synchronized, even if the
transmission from the plane is time tagged. As a matter of fact, it's
quite difficult to keep such an synchronization.
Michael Chen, BD5RV/4
AMSAT-China: http://www.camsat.cn
-----------------------------------
Twitter: http://twitter.com/bd5rv
Email: michael.bd5rv@xxxxx.xxx
MSN: bd5rv@xxxxx.xxx
Skype: michael-bd5rv
On Mon, Mar 17, 2014 at 4:27 AM, James Duffey <jamesduffey@xxxxxxx.xxx> wrote:
> I think that the transmissions from the airplane are time tagged, even
without the data packets being transmitted. By comparing the ping time to
the time on the satellite, one can tell how far away the ping is. You can
draw a circle with that radius, taking into account fuel available on the
airplane and last heading to sort of kind of bound where the airplane is.
That is where the red circles in the NY Times article come from.
>
> A second satellite is needed to pinpoint a more exact location, but even
that will have a relatively position error on the ground. I don't think it
is within range of another INMARSAT. Whether or not other assets exist that
could receive the signal is a matter of speculation. - KK6MC
>
>
> On Mar 16, 2014, at 2:01 PM, Rick Walter <wb3csy@xxxxx.xxx> wrote:
>
>> Tony, since the satellite cannot tell direction of the Ping, only
distance, the arcs have the same distance from the plane making up a half
circle. You would need to sats to hear the plane, see where the two arcs
cross to determine a location.
>>
>> This is the same way seismic stations locate earthquakes.
>>
>> Rick - WB3CSY
>>
>> Sent from Rick's iPhone 5
>> "Great spirits have always encountered violent opposition from mediocre
minds" - Albert Einstein
>>
>>
>>
>>> On Mar 16, 2014, at 12:24 PM, "Anthony Japha" <ajapha@xxxxxxxxx.xxx>
wrote:
>>>
>>> Those so-called arcs that are said to be possible routes for the plane
look much like the outer edge of one of the Inmarsat footprints. Is there
logic behind the arcs or is it oversimplified nonsense? They are said to be
the result of the signals Inmarsat received. But then why wouldn't it be
possible for the plane to be anywhere in the footprint?
>>>
>>> I'm sure many in our group have good ideas. I'm not trying to start a
discussion of the entire mystery, only this one narrow, but possibly
misleading, aspect related to our hobby.
>>>
>>> 73,
>>> Tony, N2UN
>>> LM 183
>>>
>>> ---
>>> This email is free from viruses and malware because avast! Antivirus
protection is active.
>>> http://www.avast.com
>>> _______________________________________________
>>> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
>>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>>
>> _______________________________________________
>> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>
>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 4
Date: Mon, 17 Mar 2014 11:28:04 -0400
From: Tom Busch <tom@xxxxxxxxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: Malaysian airliner puzzle
Message-ID:
<CANEZo+m-8OEDauS3X-hrNVfo+rhTdvL+AfMr3eMZHFgYFUHgsQ@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
The news has been reporting that they are using the angle of the last known
ping from the ACARS system to the satellite. This is where the 40-degree
arc around the satellite comes from.
What I don't understand is how INMARSAT knows what that angle is. CNN says
that the satellite steers its antenna to the location where it expects the
next ping, but that doesn't make sense.
I have been looking for the algorithm, but I can't find it. Signal
strength? Some sort of electronic steering? Trade secret? I don't know.
Tom WB8WOR
On Sun, Mar 16, 2014 at 10:57 PM, R.T.Liddy <k8bl@xxxxxxxxx.xxx> wrote:
> Tony,
>
> They would use the time differential between receipt
> to measure the distance versus the location of the
> satellites. The more satellites, then the more accurate
> the triangulation.
>
> 73, Bob K8BL
>
>
> ________________________________
> From: Anthony Japha <tjjapha@xxxxxxxxx.xxx>
> To: amsat-bb <amsat-bb@xxxxx.xxx>
> Sent: Sunday, March 16, 2014 4:49 PM
> Subject: [amsat-bb] Malaysian airliner puzzle
>
>
> Thanks Rick,
> How do those sats determine distance to the source?
> Tony, N2UN
>
> ---
> This email is free from viruses and malware because avast! Antivirus
> protection is active.
> http://www.avast.com
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>
------------------------------
Message: 5
Date: Mon, 17 Mar 2014 12:11:20 -0400
From: Tom Busch <tom@xxxxxxxxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: Malaysian airliner puzzle
Message-ID:
<CANEZo+n2QNzSaoOWSOWxLY6V0EhaNTf-OJi=NKA8MUhWOwetnw@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Looks like I'm wrong. The "Steering" info wasn't from CNN. It's from this
Huffington Post article:
http://www.huffingtonpost.com/2014/03/16/malaysia-airlines-takeover_n_4972889.
html.
I still would like to know how the satellite knows.
It also says that these "pings" occur every hour, so I suppose it could
have kept flying for an hour after the last contact.
Tom WB8WOR
On Mon, Mar 17, 2014 at 11:28 AM, Tom Busch <tom@xxxxxxxxxxx.xxx> wrote:
> The news has been reporting that they are using the angle of the last
> known ping from the ACARS system to the satellite. This is where the
> 40-degree arc around the satellite comes from.
>
> What I don't understand is how INMARSAT knows what that angle is. CNN
> says that the satellite steers its antenna to the location where it expects
> the next ping, but that doesn't make sense.
>
> I have been looking for the algorithm, but I can't find it. Signal
> strength? Some sort of electronic steering? Trade secret? I don't know.
>
> Tom WB8WOR
>
>
> On Sun, Mar 16, 2014 at 10:57 PM, R.T.Liddy <k8bl@xxxxxxxxx.xxx> wrote:
>
>> Tony,
>>
>> They would use the time differential between receipt
>> to measure the distance versus the location of the
>> satellites. The more satellites, then the more accurate
>> the triangulation.
>>
>> 73, Bob K8BL
>>
>>
>> ________________________________
>> From: Anthony Japha <tjjapha@xxxxxxxxx.xxx>
>> To: amsat-bb <amsat-bb@xxxxx.xxx>
>> Sent: Sunday, March 16, 2014 4:49 PM
>> Subject: [amsat-bb] Malaysian airliner puzzle
>>
>>
>> Thanks Rick,
>> How do those sats determine distance to the source?
>> Tony, N2UN
>>
>> ---
>> This email is free from viruses and malware because avast! Antivirus
>> protection is active.
>> http://www.avast.com
>> _______________________________________________
>> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>> _______________________________________________
>> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>>
>
>
------------------------------
Message: 6
Date: Tue, 18 Mar 2014 01:22:07 +0800 (SGT)
From: Nitin Muttin <vu3tyg@xxxxx.xx.xx>
To: amsat-bb <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: Malaysian airliner puzzle
Message-ID:
<1395076927.91033.YahooMailNeo@xxxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=iso-8859-1
This is really a mystery, wonder what is the ELT frequencies used on modern
aircraft , is it 121.5 Mhz or the new 406 Mhz.
?
73
Nitin [VU3TYG]
>________________________________
> From: Michael Chen <michael.bd5rv@xxxxx.xxx>
>To: amsat-bb <amsat-bb@xxxxx.xxx>
>Sent: Monday, 17 March 2014 8:35 PM
>Subject: [amsat-bb] Re: Malaysian airliner puzzle
>
>
>The distance calculated between the satellite and the plane won't be
>credible if the time on both are not synchronized, even if the
>transmission from the plane is time tagged. As a matter of fact, it's
>quite difficult to keep such an synchronization.
>
>
>
>Michael Chen, BD5RV/4
>AMSAT-China: http://www.camsat.cn
>-----------------------------------
>Twitter:? http://twitter.com/bd5rv
>Email:? michael.bd5rv@xxxxx.xxx
>MSN:? ? bd5rv@xxxxx.xxx
>Skype:? michael-bd5rv
>
>
>On Mon, Mar 17, 2014 at 4:27 AM, James Duffey <jamesduffey@xxxxxxx.xxx>
wrote:
>> I think that the transmissions from the airplane are time tagged, even
without the data packets being transmitted. By comparing the ping time to
the time on the satellite, one can tell how far away the ping is. You can
draw a circle with that radius, taking into account fuel available on the
airplane and last heading to sort of kind of bound where the airplane is.
That is where the red circles in the NY Times article come from.
>>
>> A second satellite is needed to pinpoint a more exact location, but even
that will have a relatively position error on the ground. I don't think it
is within range of another INMARSAT. Whether or not other assets exist that
could receive the signal is a matter of speculation. - KK6MC
>>
>>
>> On Mar 16, 2014, at 2:01 PM, Rick Walter <wb3csy@xxxxx.xxx> wrote:
>>
>>> Tony, since the satellite cannot tell direction of the Ping, only
distance, the arcs have the same distance from the plane making up a half
circle. You would need to sats to hear the plane, see where the two arcs
cross to determine a location.
>>>
>>> This is the same way seismic stations locate earthquakes.
>>>
>>> Rick - WB3CSY
>>>
>>> Sent from Rick's iPhone 5
>>> "Great spirits have always encountered violent opposition from mediocre
minds" - Albert Einstein
>>>
>>>
>>>
>>>> On Mar 16, 2014, at 12:24 PM, "Anthony Japha" <ajapha@xxxxxxxxx.xxx>
wrote:
>>>>
>>>> Those so-called arcs that are said to be possible routes for the plane
look much like the outer edge of one of the Inmarsat footprints.? Is there
logic behind the arcs or is it oversimplified nonsense?? They are said to be
the result of the signals Inmarsat received.? But then why wouldn't it be
possible for the plane to be anywhere in the footprint?
>>>>
>>>> I'm sure many in our group have good ideas.? I'm not trying to start a
discussion of the entire mystery, only this one narrow, but possibly
misleading, aspect related to our hobby.
>>>>
>>>> 73,
>>>> Tony, N2UN
>>>> LM 183
>>>>
>>>> ---
>>>> This email is free from viruses and malware because avast! Antivirus
protection is active.
>>>> http://www.avast.com
>>>> _______________________________________________
>>>> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
>>>> Not an AMSAT-NA member? Join now to support the amateur satellite
program!
>>>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>
>>>
>>> _______________________________________________
>>> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
>>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>>
>>
>> _______________________________________________
>> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>
>_______________________________________________
>Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
>Not an AMSAT-NA member? Join now to support the amateur satellite program!
>Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>
>
>
------------------------------
Message: 7
Date: Mon, 17 Mar 2014 12:28:11 -0500
From: Chandler Heath <convergx@xxxxx.xxx>
To: Tom Busch <tom@xxxxxxxxxxx.xxx>
Cc: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: Malaysian airliner puzzle
Message-ID: <4897F8F8-0C16-441E-A9C5-5DFBC5CF490E@xxxxx.xxx>
Content-Type: text/plain; charset=us-ascii
I read that the "handshakes" were still occurring when they lost contact
with the aircraft. In an article posted here from the Inmarsat web site
Inmarsat mentioned that they and their partner Sita are working with
officials to use handshakes to triangulate the position.
On the topic of Steering, the satellites have the capability to "steer" spot
beams to address capacity needs, but to "steer" for one subscriber would
make things worse for the others.
Here is a link on the Sita service OnAir. I don't know how accurate it is,
but here it is for anyone that may want to learn more.
http://en.m.wikipedia.org/wiki/OnAir_(telecommunications)
Sent from my iPhone
> On Mar 17, 2014, at 11:11 AM, Tom Busch <tom@xxxxxxxxxxx.xxx> wrote:
>
> Looks like I'm wrong. The "Steering" info wasn't from CNN. It's from this
> Huffington Post article:
>
http://www.huffingtonpost.com/2014/03/16/malaysia-airlines-takeover_n_4972889.
html.
> I still would like to know how the satellite knows.
>
> It also says that these "pings" occur every hour, so I suppose it could
> have kept flying for an hour after the last contact.
> Tom WB8WOR
>
>> On Mon, Mar 17, 2014 at 11:28 AM, Tom Busch <tom@xxxxxxxxxxx.xxx> wrote:
>>
>> The news has been reporting that they are using the angle of the last
>> known ping from the ACARS system to the satellite. This is where the
>> 40-degree arc around the satellite comes from.
>>
>> What I don't understand is how INMARSAT knows what that angle is. CNN
>> says that the satellite steers its antenna to the location where it expects
>> the next ping, but that doesn't make sense.
>>
>> I have been looking for the algorithm, but I can't find it. Signal
>> strength? Some sort of electronic steering? Trade secret? I don't know.
>>
>> Tom WB8WOR
>>
>>
>>> On Sun, Mar 16, 2014 at 10:57 PM, R.T.Liddy <k8bl@xxxxxxxxx.xxx> wrote:
>>>
>>> Tony,
>>>
>>> They would use the time differential between receipt
>>> to measure the distance versus the location of the
>>> satellites. The more satellites, then the more accurate
>>> the triangulation.
>>>
>>> 73, Bob K8BL
>>>
>>>
>>> ________________________________
>>> From: Anthony Japha <tjjapha@xxxxxxxxx.xxx>
>>> To: amsat-bb <amsat-bb@xxxxx.xxx>
>>> Sent: Sunday, March 16, 2014 4:49 PM
>>> Subject: [amsat-bb] Malaysian airliner puzzle
>>>
>>>
>>> Thanks Rick,
>>> How do those sats determine distance to the source?
>>> Tony, N2UN
>>>
>>> ---
>>> This email is free from viruses and malware because avast! Antivirus
>>> protection is active.
>>> http://www.avast.com
>>> _______________________________________________
>>> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
>>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>>> _______________________________________________
>>> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
>>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 8
Date: Mon, 17 Mar 2014 12:40:05 -0500
From: Joe <nss@xxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: Malaysian airliner puzzle
Message-ID: <53273375.40206@xxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
What I do not understand is why the Transponder is capable of being shut
off at all?
That thing as soon as the plane is powered up should start transmitting,
and continue to do so till the plane is shut down. And have no way
anyone can shut it off in any way.
Why does something like this seem sooo simple?
Then The the "Black Box" There is also no reason what so ever that it
has to be the only recording of the planes parameters. Sure record it,
no problem, BUT... there is no reason why this can not be transmitted
live or compressed and transmitted in packets to ground stations to
save. This way if a plane goes down you do not need to "Recover" the
"Black Box" every bit of data is already on the ground saved.
Again Like DUH?
Joe WB9SBD
Sig
The Original Rolling Ball Clock
Idle Tyme
Idle-Tyme.com
http://www.idle-tyme.com
On 3/17/2014 12:22 PM, Nitin Muttin wrote:
> This is really a mystery, wonder what is the ELT frequencies used on
modern aircraft , is it 121.5 Mhz or the new 406 Mhz.
>
> 73
> Nitin [VU3TYG]
>
>
>> ________________________________
>> From: Michael Chen <michael.bd5rv@xxxxx.xxx>
>> To: amsat-bb <amsat-bb@xxxxx.xxx>
>> Sent: Monday, 17 March 2014 8:35 PM
>> Subject: [amsat-bb] Re: Malaysian airliner puzzle
>>
>>
>> The distance calculated between the satellite and the plane won't be
>> credible if the time on both are not synchronized, even if the
>> transmission from the plane is time tagged. As a matter of fact, it's
>> quite difficult to keep such an synchronization.
>>
>>
>>
>> Michael Chen, BD5RV/4
>> AMSAT-China: http://www.camsat.cn
>> -----------------------------------
>> Twitter: http://twitter.com/bd5rv
>> Email: michael.bd5rv@xxxxx.xxx
>> MSN: bd5rv@xxxxx.xxx
>> Skype: michael-bd5rv
>>
>>
>> On Mon, Mar 17, 2014 at 4:27 AM, James Duffey <jamesduffey@xxxxxxx.xxx>
wrote:
>>> I think that the transmissions from the airplane are time tagged, even
without the data packets being transmitted. By comparing the ping time to
the time on the satellite, one can tell how far away the ping is. You can
draw a circle with that radius, taking into account fuel available on the
airplane and last heading to sort of kind of bound where the airplane is.
That is where the red circles in the NY Times article come from.
>>>
>>> A second satellite is needed to pinpoint a more exact location, but even
that will have a relatively position error on the ground. I don't think it
is within range of another INMARSAT. Whether or not other assets exist that
could receive the signal is a matter of speculation. - KK6MC
>>>
>>>
>>> On Mar 16, 2014, at 2:01 PM, Rick Walter <wb3csy@xxxxx.xxx> wrote:
>>>
>>>> Tony, since the satellite cannot tell direction of the Ping, only
distance, the arcs have the same distance from the plane making up a half
circle. You would need to sats to hear the plane, see where the two arcs
cross to determine a location.
>>>>
>>>> This is the same way seismic stations locate earthquakes.
>>>>
>>>> Rick - WB3CSY
>>>>
>>>> Sent from Rick's iPhone 5
>>>> "Great spirits have always encountered violent opposition from mediocre
minds" - Albert Einstein
>>>>
>>>>
>>>>
>>>>> On Mar 16, 2014, at 12:24 PM, "Anthony Japha" <ajapha@xxxxxxxxx.xxx>
wrote:
>>>>>
>>>>> Those so-called arcs that are said to be possible routes for the plane
look much like the outer edge of one of the Inmarsat footprints. Is there
logic behind the arcs or is it oversimplified nonsense? They are said to be
the result of the signals Inmarsat received. But then why wouldn't it be
possible for the plane to be anywhere in the footprint?
>>>>>
>>>>> I'm sure many in our group have good ideas. I'm not trying to start a
discussion of the entire mystery, only this one narrow, but possibly
misleading, aspect related to our hobby.
>>>>>
>>>>> 73,
>>>>> Tony, N2UN
>>>>> LM 183
>>>>>
>>>>> ---
>>>>> This email is free from viruses and malware because avast! Antivirus
protection is active.
>>>>> http://www.avast.com
>>>>> _______________________________________________
>>>>> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
>>>>> Not an AMSAT-NA member? Join now to support the amateur satellite
program!
>>>>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>>>> _______________________________________________
>>>> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
>>>> Not an AMSAT-NA member? Join now to support the amateur satellite
program!
>>>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>>>
>>> _______________________________________________
>>> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
>>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>> _______________________________________________
>> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>>
>>
>>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>
>
>
------------------------------
Message: 9
Date: Tue, 18 Mar 2014 01:58:06 +0800 (SGT)
From: Nitin Muttin <vu3tyg@xxxxx.xx.xx>
To: amsat-bb <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: Malaysian airliner puzzle
Message-ID:
<1395079086.63025.YahooMailNeo@xxxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=iso-8859-1
Sorry if off topic.
Looks like it is all three 121.5 / 243/ 406
?http://www.acrartex.com/products/catalog/elts-commercialmilitary/b406-4/?
If the aircraft did crash in Bay of Bengal / Indian ocean and ELT
operational the signals would have been picked up by satellites
.http://inmcc.istrac.org/brochurehtml/index.htm
73
Nitin [VU3TYG]
>________________________________
> From: Nitin Muttin <vu3tyg@xxxxx.xx.xx>
>To: amsat-bb <amsat-bb@xxxxx.xxx>
>Sent: Monday, 17 March 2014 10:52 PM
>Subject: Re: [amsat-bb] Re: Malaysian airliner puzzle
>
>
>
>This is really a mystery, wonder what is the ELT frequencies used on modern
aircraft , is it 121.5 Mhz or the new 406 Mhz.
>?
>73
>Nitin [VU3TYG]
>
>
>
>>________________________________
>> From: Michael Chen <michael.bd5rv@xxxxx.xxx>
>>To: amsat-bb <amsat-bb@xxxxx.xxx>
>>Sent: Monday, 17 March 2014 8:35 PM
>>Subject: [amsat-bb] Re: Malaysian airliner puzzle
>>
>>
>>The distance calculated between the satellite and the plane won't be
>>credible if the time on both are not synchronized, even if the
>>transmission from the plane is time tagged. As a matter of fact, it's
>>quite difficult to keep such an synchronization.
>>
>>
>>
>>Michael Chen, BD5RV/4
>>AMSAT-China: http://www.camsat.cn
>>-----------------------------------
>>Twitter:? http://twitter.com/bd5rv
>>Email:? michael.bd5rv@xxxxx.xxx
>>MSN:? ? bd5rv@xxxxx.xxx
>>Skype:? michael-bd5rv
>>
>>
>>On Mon, Mar 17, 2014 at 4:27 AM, James Duffey <jamesduffey@xxxxxxx.xxx>
wrote:
>>> I think that the transmissions from the airplane are time tagged, even
without the data packets being transmitted. By comparing the ping time to
the time on the satellite, one can tell how far away the ping is. You can
draw a circle with that radius, taking into account fuel available on the
airplane and last heading to sort of kind of bound where the airplane is.
That is where the red circles in the NY Times article come from.
>>>
>>> A second satellite is needed to pinpoint a more exact location, but even
that will have a relatively position error on the ground. I don't think it
is within range of another INMARSAT. Whether or not other assets exist that
could receive the signal is a matter of speculation. - KK6MC
>>>
>>>
>>> On Mar 16, 2014, at 2:01 PM, Rick Walter <wb3csy@xxxxx.xxx> wrote:
>>>
>>>> Tony, since the satellite cannot tell direction of the Ping, only
distance, the arcs have the same distance from the plane making up a half
circle. You would need to sats to hear the plane, see where the two arcs
cross to determine a location.
>>>>
>>>> This is the same way seismic stations locate earthquakes.
>>>>
>>>> Rick - WB3CSY
>>>>
>>>> Sent from Rick's iPhone 5
>>>> "Great spirits have always encountered violent opposition from mediocre
minds" - Albert Einstein
>>>>
>>>>
>>>>
>>>>> On Mar 16, 2014, at 12:24 PM, "Anthony Japha" <ajapha@xxxxxxxxx.xxx>
wrote:
>>>>>
>>>>> Those so-called arcs that are said to be possible routes for the plane
look much like the outer edge of one of the Inmarsat footprints.? Is there
logic behind the arcs or is it oversimplified nonsense?? They are said to be
the result of the signals Inmarsat received.? But then why wouldn't it be
possible for the plane to be anywhere in the footprint?
>>>>>
>>>>> I'm sure many in our group have good ideas.? I'm not trying to start a
discussion of the entire mystery, only this one narrow, but possibly
misleading, aspect related to our hobby.
>>>>>
>>>>> 73,
>>>>> Tony, N2UN
>>>>> LM 183
>>>>>
>>>>> ---
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protection is active.
>>>>> http://www.avast.com
>>>>> _______________________________________________
>>>>> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
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>>>>
>>>> _______________________________________________
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>>>
>>>
_______________________________________________
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>>
>>_______________________________________________
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>>
>>
>
>
------------------------------
Message: 10
Date: Mon, 17 Mar 2014 14:14:03 -0400
From: Tom Busch <tom@xxxxxxxxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: Malaysian airliner puzzle
Message-ID:
<CANEZo+nGag8Gmb=pU95SKSEWw=qiXqckMZZscWGpwBvBwuV0tA@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Now I get it...
The satellite "pings" the plane, which responds with "I am here." By
measuring the round trip time between the transmit and receive signals, the
satellite can determine the aircraft's distance, and thus the angle to it.
Article here: http://theaviationist.com/2014/03/16/satcom-acars-explained/
Tom WB8WOR
On Mon, Mar 17, 2014 at 1:28 PM, Chandler Heath <convergx@xxxxx.xxx> wrote:
> I read that the "handshakes" were still occurring when they lost contact
> with the aircraft. In an article posted here from the Inmarsat web site
> Inmarsat mentioned that they and their partner Sita are working with
> officials to use handshakes to triangulate the position.
>
> On the topic of Steering, the satellites have the capability to "steer"
> spot beams to address capacity needs, but to "steer" for one subscriber
> would make things worse for the others.
>
> Here is a link on the Sita service OnAir. I don't know how accurate it is,
> but here it is for anyone that may want to learn more.
>
> http://en.m.wikipedia.org/wiki/OnAir_(telecommunications)
>
> Sent from my iPhone
>
> > On Mar 17, 2014, at 11:11 AM, Tom Busch <tom@xxxxxxxxxxx.xxx> wrote:
> >
> > Looks like I'm wrong. The "Steering" info wasn't from CNN. It's from
> this
> > Huffington Post article:
> >
>
http://www.huffingtonpost.com/2014/03/16/malaysia-airlines-takeover_n_4972889.
html
> .
> > I still would like to know how the satellite knows.
> >
> > It also says that these "pings" occur every hour, so I suppose it could
> > have kept flying for an hour after the last contact.
> > Tom WB8WOR
> >
> >> On Mon, Mar 17, 2014 at 11:28 AM, Tom Busch <tom@xxxxxxxxxxx.xxx>
> wrote:
> >>
> >> The news has been reporting that they are using the angle of the last
> >> known ping from the ACARS system to the satellite. This is where the
> >> 40-degree arc around the satellite comes from.
> >>
> >> What I don't understand is how INMARSAT knows what that angle is. CNN
> >> says that the satellite steers its antenna to the location where it
> expects
> >> the next ping, but that doesn't make sense.
> >>
> >> I have been looking for the algorithm, but I can't find it. Signal
> >> strength? Some sort of electronic steering? Trade secret? I don't
> know.
> >>
> >> Tom WB8WOR
> >>
> >>
> >>> On Sun, Mar 16, 2014 at 10:57 PM, R.T.Liddy <k8bl@xxxxxxxxx.xxx>
> wrote:
> >>>
> >>> Tony,
> >>>
> >>> They would use the time differential between receipt
> >>> to measure the distance versus the location of the
> >>> satellites. The more satellites, then the more accurate
> >>> the triangulation.
> >>>
> >>> 73, Bob K8BL
> >>>
> >>>
> >>> ________________________________
> >>> From: Anthony Japha <tjjapha@xxxxxxxxx.xxx>
> >>> To: amsat-bb <amsat-bb@xxxxx.xxx>
> >>> Sent: Sunday, March 16, 2014 4:49 PM
> >>> Subject: [amsat-bb] Malaysian airliner puzzle
> >>>
> >>>
> >>> Thanks Rick,
> >>> How do those sats determine distance to the source?
> >>> Tony, N2UN
> >>>
> >>> ---
> >>> This email is free from viruses and malware because avast! Antivirus
> >>> protection is active.
> >>> http://www.avast.com
> >>> _______________________________________________
> >>> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the
> author.
> >>> Not an AMSAT-NA member? Join now to support the amateur satellite
> program!
> >>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
> >>> _______________________________________________
> >>> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the
> author.
> >>> Not an AMSAT-NA member? Join now to support the amateur satellite
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> >>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
> > _______________________________________________
> > Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
> > Not an AMSAT-NA member? Join now to support the amateur satellite
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>
------------------------------
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Sent via amsat-bb@xxxxx.xxx. Opinions expressed are those of the author.
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End of AMSAT-BB Digest, Vol 9, Issue 95
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