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Date: 13 Aug 2006 05:06:31
From:
Subject: Celestron SkyScout's a winner
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Wellllll, I couldn't resist. My buddies at the local Orion store in
Cupertino (California) called last Wednesday stating the units are
trickling in and they'd hold one for me. So I bought one yesterday and,
without a doubt, Celestron has a real winner here.
A mini-review, PDF manual and docs, and pictures can be found at:
<http://thadlabs.com/ASTRO/SkyScout/ >
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Date: 13 Aug 2006 13:05:19
From: Phil Wheeler
Subject: Re: Celestron SkyScout's a winner
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thad@thadlabs.com wrote:
> Wellllll, I couldn't resist. My buddies at the local Orion store in
> Cupertino (California) called last Wednesday stating the units are
> trickling in and they'd hold one for me. So I bought one yesterday
> and, without a doubt, Celestron has a real winner here.
>
> A mini-review, PDF manual and docs, and pictures can be found at:
>
> <http://thadlabs.com/ASTRO/SkyScout/>
>
Thad,
You say "The SkyScout is a handheld device incorporating GPS technology
and solid-state compass and altitude sensors ..."
Do you mean 'altitude' or 'attitude'?
Phil
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Date: 13 Aug 2006 13:35:35
From: Chris L Peterson
Subject: Re: Celestron SkyScout's a winner
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On Sun, 13 Aug 2006 13:05:19 GMT, Phil Wheeler <wt6uh-ng7@yahoo.com >
wrote:
>You say "The SkyScout is a handheld device incorporating GPS technology
>and solid-state compass and altitude sensors ..."
>
>Do you mean 'altitude' or 'attitude'?
The combination of an azimuth sensor (compass) and altitude sensor
(inclinometer) adds up to an attitude sensor.
_________________________________________________
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
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Date: 13 Aug 2006 15:26:07
From: Phil Wheeler
Subject: Re: Celestron SkyScout's a winner
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Chris L Peterson wrote:
> On Sun, 13 Aug 2006 13:05:19 GMT, Phil Wheeler <wt6uh-ng7@yahoo.com>
> wrote:
>
>> You say "The SkyScout is a handheld device incorporating GPS technology
>> and solid-state compass and altitude sensors ..."
>>
>> Do you mean 'altitude' or 'attitude'?
>
> The combination of an azimuth sensor (compass) and altitude sensor
> (inclinometer) adds up to an attitude sensor.
>
>
Altitude is measured in meters or feet. An inclinometer measures
attitude, not altitude.
Phil
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Date: 13 Aug 2006 16:22:17
From: Chris L Peterson
Subject: Re: Celestron SkyScout's a winner
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On Sun, 13 Aug 2006 15:26:07 GMT, Phil Wheeler <wt6uh-ng7@yahoo.com >
wrote:
>Altitude is measured in meters or feet. An inclinometer measures
>attitude, not altitude.
I disagree. The altitude axis on my altaz mount isn't calibrated in
meters or feet.
My dictionary (MW 11th Collegiate) gives the first definition for
"altitude" as "the angular elevation of a celestial object above the
horizon" ("elevation" is as ambiguous as "altitude"). The relevant
definition for "attitude" is "the position of an aircraft or spacecraft
determined by the relationship between its axes and a reference datum
(as the horizon or a particular star)". An inclinometer can only give
one component of attitude, and that is the altitude.
BTW, in my work with meteors, where there is a real possibility of
confusion, I am careful to distinguish "altitude", the angle of the
meteor above the horizon, from "height", the distance of the meteoroid
above the ground.
_________________________________________________
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
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Date: 14 Aug 2006 02:58:24
From: KPotato
Subject: Re: Celestron SkyScout's a winner
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Chris L Peterson wrote:
> On Sun, 13 Aug 2006 15:26:07 GMT, Phil Wheeler <wt6uh-ng7@yahoo.com>
> wrote:
>
> >Altitude is measured in meters or feet. An inclinometer measures
> >attitude, not altitude.
>
> I disagree. The altitude axis on my altaz mount isn't calibrated in
> meters or feet.
>
> My dictionary (MW 11th Collegiate) gives the first definition for
> "altitude" as "the angular elevation of a celestial object above the
> horizon" ("elevation" is as ambiguous as "altitude"). The relevant
> definition for "attitude" is "the position of an aircraft or spacecraft
> determined by the relationship between its axes and a reference datum
> (as the horizon or a particular star)".
> An inclinometer can only give
> one component of attitude, and that is the altitude.
Precisely. Incline vs recline. Inclination. Incline as to rise "above" or
"tend toward" some commonly accepted reference point or plane, as in
horizon. Inclin-o-meter. A device specific which measures "inclination".
>
>
> BTW, in my work with meteors, where there is a real possibility of
> confusion, I am careful to distinguish "altitude", the angle of the
> meteor above the horizon, from "height", the distance of the meteoroid
> above the ground.
>
> _________________________________________________
>
> Chris L Peterson
> Cloudbait Observatory
> http://www.cloudbait.com
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Date: 13 Aug 2006 15:55:37
From: Pierre Vandevennne
Subject: Re: Celestron SkyScout's a winner
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Phil Wheeler <wt6uh-ng7@yahoo.com > wrote in news:jwHDg.174$S_5.132
@tornado.socal.rr.com:
> Chris L Peterson wrote:
>> On Sun, 13 Aug 2006 13:05:19 GMT, Phil Wheeler <wt6uh-ng7@yahoo.com>
>> wrote:
>>
>>> You say "The SkyScout is a handheld device incorporating GPS technology
>>> and solid-state compass and altitude sensors ..."
>>>
>>> Do you mean 'altitude' or 'attitude'?
>>
>> The combination of an azimuth sensor (compass) and altitude sensor
>> (inclinometer) adds up to an attitude sensor.
>>
>>
>
> Altitude is measured in meters or feet. An inclinometer measures
> attitude, not altitude.
As far as altitude goes, doesn't the sky sensor rely on GPS + WAAS only?
I've found this to be extremely accurate 2-3 in both the vertical and
horizontal plane on my "trekking" GPS. One doesn't need more than something
like a SQ-SI2X-360DA, a GPS chipset and of course some code to implement
the skyscout functionality imho.
Has anyone opened the beast?
Last but not least: I am still not really getting why such a thing could be
useful. Implementing the functinality in a self locating and aligning scope
could make them even more dumb proof, yes, but why would anyone want to use
the handheld device?
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Date: 13 Aug 2006 22:07:37
From: Chris L Peterson
Subject: Re: Celestron SkyScout's a winner
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On 13 Aug 2006 15:55:37 GMT, Pierre Vandevennne
<pierre@datarescue_ns.com > wrote:
>As far as altitude goes, doesn't the sky sensor rely on GPS + WAAS only?
>I've found this to be extremely accurate 2-3 in both the vertical and
>horizontal plane on my "trekking" GPS. One doesn't need more than something
>like a SQ-SI2X-360DA, a GPS chipset and of course some code to implement
>the skyscout functionality imho.
How do you figure? Altitude (i.e., height above sea level) is of no use
at all. The unit needs a 2D topocentric location (latitude and
longitude), but hardly to WAAS accuracy, and it needs two dimensions of
attitude: altitude (degrees above the horizon) and azimuth (compass
angle). Neither of the latter two are available from the GPS.
_________________________________________________
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
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Date: 13 Aug 2006 23:49:25
From: Sam Wormley
Subject: Re: Celestron SkyScout's a winner
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Chris L Peterson wrote:
> On 13 Aug 2006 15:55:37 GMT, Pierre Vandevennne
> <pierre@datarescue_ns.com> wrote:
>
>> As far as altitude goes, doesn't the sky sensor rely on GPS + WAAS only?
>> I've found this to be extremely accurate 2-3 in both the vertical and
>> horizontal plane on my "trekking" GPS. One doesn't need more than something
>> like a SQ-SI2X-360DA, a GPS chipset and of course some code to implement
>> the skyscout functionality imho.
>
> How do you figure? Altitude (i.e., height above sea level) is of no use
> at all. The unit needs a 2D topocentric location (latitude and
> longitude), but hardly to WAAS accuracy, and it needs two dimensions of
> attitude: altitude (degrees above the horizon) and azimuth (compass
> angle). Neither of the latter two are available from the GPS.
At least not without multiple antennae. There is equipment (military)
which achieves a fraction of a degree pointing (or orientation) accuracy
http://trimble.resultspage.com/search?p=Q&ts=custom&w=Tans%20vector
which, of course, is overkill. As you point out--compass and inclinometer
are sufficiently accurate to determine attitude.
-Sam
>
> _________________________________________________
>
> Chris L Peterson
> Cloudbait Observatory
> http://www.cloudbait.com
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Date: 13 Aug 2006 22:26:19
From: Pierre Vandevennne
Subject: Re: Celestron SkyScout's a winner
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Chris L Peterson <clp@alumni.caltech.edu > wrote in
news:9g8vd2dbgeuchmiahrcmgacqp50vigqv4s@4ax.com:
> How do you figure? Altitude (i.e., height above sea level) is of no
> use at all.
Minor differences certainly don't matter, but what about a couple of
kilometers?
> longitude), but hardly to WAAS accuracy, and it needs two dimensions
> of attitude: altitude (degrees above the horizon) and azimuth (compass
> angle). Neither of the latter two are available from the GPS.
Which is precisely why I suggested that it may use something similar to
that SQ-SI2X-360DA
http://tinyurl.com/s2mlq
I still believe a GPS chipset is needed, along with something similar to
SQ-SI2X-360DA
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Date: 13 Aug 2006 23:10:48
From: Phil Wheeler
Subject: Re: Celestron SkyScout's a winner
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Pierre Vandevennne wrote:
> Chris L Peterson <clp@alumni.caltech.edu> wrote in
> news:9g8vd2dbgeuchmiahrcmgacqp50vigqv4s@4ax.com:
>
>> How do you figure? Altitude (i.e., height above sea level) is of no
>> use at all.
>
> Minor differences certainly don't matter, but what about a couple of
> kilometers?
>
Not to worry: GPS can do *that* well.
Phil
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Date: 13 Aug 2006 22:38:15
From: Chris L Peterson
Subject: Re: Celestron SkyScout's a winner
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On 13 Aug 2006 22:26:19 GMT, Pierre Vandevennne
<pierre@datarescue_ns.com > wrote:
>Minor differences certainly don't matter, but what about a couple of
>kilometers?
Nope. Even for some transient object passing close to the Earth, it
wouldn't matter for a unit power device like the Sky Scout. I'm sure
that the unit doesn't make use of geocentric/topocentric corrections at
all. It just needs the position so it can convert polar coordinates to
altaz.
>Which is precisely why I suggested that it may use something similar to
>that SQ-SI2X-360DA
Sorry, I misunderstood you. I thought you were giving the number for a
GPS chipset. This is exactly the sort of device I would think they use
for determining inclination. They also need an electronic compass, which
is yet another fairly inexpensive device. The compass, of course, is the
big weakness in this system since magnetic deviation is frequently both
large and unpredictable. Accuracy to a degree or two is probably about
the best that can be expected in azimuth. Again, though, that's probably
not much of a problem with a unit power device. It would fall apart
pretty quickly with any magnification, though.
_________________________________________________
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
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Date: 14 Aug 2006 00:14:14
From: Pierre Vandevennne
Subject: Re: Celestron SkyScout's a winner
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Chris L Peterson <clp@alumni.caltech.edu > wrote in
news:b3avd2tp49hldnq06niv2gum23hruco2lo@4ax.com:
> On 13 Aug 2006 22:26:19 GMT, Pierre Vandevennne
> <pierre@datarescue_ns.com> wrote:
>>Which is precisely why I suggested that it may use something similar to
>>that SQ-SI2X-360DA
>
> Sorry, I misunderstood you. I thought you were giving the number for a
> GPS chipset. This is exactly the sort of device I would think they use
No problem, I realized the wording of my first post was a bit ambiguous.
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Date: 13 Aug 2006 18:10:15
From: Joe S.
Subject: Re: Celestron SkyScout's a winner
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"Phil Wheeler" <wt6uh-ng7@yahoo.com > wrote in message
news:jwHDg.174$S_5.132@tornado.socal.rr.com...
> Chris L Peterson wrote:
>> On Sun, 13 Aug 2006 13:05:19 GMT, Phil Wheeler <wt6uh-ng7@yahoo.com>
>> wrote:
>>
>>> You say "The SkyScout is a handheld device incorporating GPS technology
>>> and solid-state compass and altitude sensors ..."
>>>
>>> Do you mean 'altitude' or 'attitude'?
>>
>> The combination of an azimuth sensor (compass) and altitude sensor
>> (inclinometer) adds up to an attitude sensor.
>>
>>
>
> Altitude is measured in meters or feet. An inclinometer measures
> attitude, not altitude.
>
> Phil
Well, before reading this thread and continuing as I read it, I was sipping
two fingers of Wild Turkey and I gotta tell you, the Wild Turkey smoothed
out my attitude and increased my altitude and now my inclinometer is showing
a distinct lean.
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Date: 13 Aug 2006 18:26:18
From: Art
Subject: Re: Celestron SkyScout's a winner
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"Joe S." <anon@mous.net > wrote in message
news:ebo82i02ksc@news1.newsguy.com...
>
> "Phil Wheeler" <wt6uh-ng7@yahoo.com> wrote in message
> news:jwHDg.174$S_5.132@tornado.socal.rr.com...
>> Chris L Peterson wrote:
>>> On Sun, 13 Aug 2006 13:05:19 GMT, Phil Wheeler <wt6uh-ng7@yahoo.com>
>>> wrote:
>>>
>>>> You say "The SkyScout is a handheld device incorporating GPS technology
>>>> and solid-state compass and altitude sensors ..."
>>>>
>>>> Do you mean 'altitude' or 'attitude'?
>>>
>>> The combination of an azimuth sensor (compass) and altitude sensor
>>> (inclinometer) adds up to an attitude sensor.
>>>
>>>
>>
>> Altitude is measured in meters or feet. An inclinometer measures
>> attitude, not altitude.
>>
>> Phil
>
> Well, before reading this thread and continuing as I read it, I was
> sipping two fingers of Wild Turkey and I gotta tell you, the Wild Turkey
> smoothed out my attitude and increased my altitude and now my inclinometer
> is showing a distinct lean.
>
>
POTD!
Art
"I ain't in no slump, I just ain't hittin." - Yogi Berra
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Date: 13 Aug 2006 16:27:16
From:
Subject: Re: Celestron SkyScout's a winner
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Chris L Peterson wrote:
> [...]
> How do you figure? Altitude (i.e., height above sea level) is of no use
> at all. The unit needs a 2D topocentric location (latitude and
> longitude), but hardly to WAAS accuracy, and it needs two dimensions of
> attitude: altitude (degrees above the horizon) and azimuth (compass
> angle). Neither of the latter two are available from the GPS.
But are from chips and cards such as those found here from PNI
Corporation:
<http://www.pnicorp.com/ >
which are what I speculated would be used in the SkyScout back when it
was
first announced, what, 8+ months ago. I'll probably open the unit up
to see
what's inside, but that won't happen today.
FWIW, Meade's LX200GPS scopes perform almost the identical functions
as the SkyScout: locate, identify, and describe.
Hmmm, just now noticed one of the "Help- >About" menu selections in the
SkyScout cite these US patents (if anyone wants to look them up):
US6570506
US6844822
under license from Yamcon, Inc.
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Date: 14 Aug 2006 00:12:29
From: Pierre Vandevennne
Subject: Re: Celestron SkyScout's a winner
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thad@thadlabs.com wrote in news:1155511636.253332.133030
@b28g2000cwb.googlegroups.com:
> US6570506
> US6844822
http://www.freepatentsonline.com/US6570506.html
http://www.freepatentsonline.com/US6844822.html
not much, but they mention "three axis magnetic field"
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Date: 13 Aug 2006 14:36:41
From:
Subject: Re: Celestron SkyScout's a winner
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Pierre Vandevennne wrote:
> [...]
> Last but not least: I am still not really getting why such a thing could be
> useful. Implementing the functinality in a self locating and aligning scope
> could make them even more dumb proof, yes, but why would anyone want to use
> the handheld device?
The "handheld" device has a 1/4-20 tripod mounting hole which would
permit
piggy-backing atop an OTA to permit GOTO scope alignment daytime --
stars
and planets are visible/viewable/photographable if one knows where to
point.
Its primary use is as a computerized planisphere/chart which benefits
all
amateur astronomers; other paper, plastic, electronic, and
build-it-yourself
planispheres can be seen here:
<http://thadlabs.com/ASTRO/Planispheres/ >
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Date: 13 Aug 2006 14:31:15
From:
Subject: Re: Celestron SkyScout's a winner
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Phil Wheeler wrote:
> thad@thadlabs.com wrote:
> > Wellllll, I couldn't resist. My buddies at the local Orion store in
> > Cupertino (California) called last Wednesday stating the units are
> > trickling in and they'd hold one for me. So I bought one yesterday
> > and, without a doubt, Celestron has a real winner here.
> >
> > A mini-review, PDF manual and docs, and pictures can be found at:
> >
> > <http://thadlabs.com/ASTRO/SkyScout/>
> >
>
> Thad,
>
> You say "The SkyScout is a handheld device incorporating GPS technology
> and solid-state compass and altitude sensors ..."
>
> Do you mean 'altitude' or 'attitude'?
Altitude as in azimuth/altitude. At 5am, still awake after 22 hours
and a day full
food shopping, house chores, car service, new toy acquisition, etc. I'm
surprised I
was even able to operate my camera to take the pictures of the
SkyScout. :-)
Celestron states it uses a "gravity sensor" which I really doubt; my
guess is it uses
the same sensor(s) as in the "Smart Tool", whose angular accuracy is
0.1 degree, as
can be seen here:
<http://thadlabs.com/ASTRO/TOOLS/ >
If I didn't have other commitments today I'd open it up for a look-see.
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Date: 13 Aug 2006 22:11:12
From: Chris L Peterson
Subject: Re: Celestron SkyScout's a winner
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On 13 Aug 2006 14:31:15 -0700, thad@thadlabs.com wrote:
>Celestron states it uses a "gravity sensor" which I really doubt; my
>guess is it uses
>the same sensor(s) as in the "Smart Tool", whose angular accuracy is
>0.1 degree, as
>can be seen here:
>
><http://thadlabs.com/ASTRO/TOOLS/>
>
>If I didn't have other commitments today I'd open it up for a look-see.
I have an old Smart Level, and it uses a mechanical sensor- essentially
a pendulum and an optical encoder. But integrated three-axis
accelerometers are now a cheap commodity- just a few dollars- and they
are more accurate than 0.1°. I would expect that's what Celestron uses
(I'd also suspect it is what newer electronic levels use).
If you open yours up, take some nice pictures. I'd love to see the guts.
_________________________________________________
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
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Date: 13 Aug 2006 22:19:41
From:
Subject: Re: Celestron SkyScout's a winner
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thad@thadlabs.com wrote:
> Wellllll, I couldn't resist. My buddies at the local Orion store in
> Cupertino (California) called last Wednesday stating the units are
> trickling in and they'd hold one for me. So I bought one yesterday and,
> without a doubt, Celestron has a real winner here.
> [...]
I had some time to perform daytime testing of the SkyScout. Quick
summary:
1. it functions fine daytime though there's a contrast difficulty
seeing the
guide LEDs, solvable using a piece of FPI ProtoStar black flocking
paper
2. it functions fine piggybacked atop an OTA on a tracking mount. I
didn't
have time or opportunity to fab a mounting bracket for an LX200 so
today's
test used a SkyView Pro mount carrying an Orion ED80
More photos and updated text [13-Aug-2006 19:45 PDT] available at:
<http://thadlabs.com/ASTRO/SkyScout/ >
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