Re: [time-nuts] nuts about position (cheap receiver)
On Wed, May 2, 2018 11:36 pm, Mark Sims wrote:
have Heather do all the receiver configuring, data
capture, and RINEX making...
I have been following along with the update messages, and this seems like
really cool improvements to the underlying infrastructure pieces that a
lot of us use (Lady Heather, support for more GPS modules, etc.), but I
am having trouble putting all the pieces together.
Having submitted the files to some post-processing server, do you only get
back information showing your position to some small number of
centimeters, or does it send back a stream of values showing the
corrections to the full position + time equations at each reading?
Can you use this data to go back to, for example, a stream of timestamps
and add a correction factor to the timestamps to get improved time
accuracy on historical data?
--
Chris Caudle
Hi
The sites are aimed at improving position information. To the degree that having an
accurate location for your antenna improves timing, simply doing that is a step forward
for your GPSDO.
Most sites also will give you information that shows the timing solution at a given point
in time. To the degree that you can connect that to prior data it could be useful. There
are more than a few steps involved in getting this to work.
Bob
On May 3, 2018, at 10:17 AM, Chris Caudle chris@chriscaudle.org wrote:
On Wed, May 2, 2018 11:36 pm, Mark Sims wrote:
have Heather do all the receiver configuring, data
capture, and RINEX making...
I have been following along with the update messages, and this seems like
really cool improvements to the underlying infrastructure pieces that a
lot of us use (Lady Heather, support for more GPS modules, etc.), but I
am having trouble putting all the pieces together.
Having submitted the files to some post-processing server, do you only get
back information showing your position to some small number of
centimeters, or does it send back a stream of values showing the
corrections to the full position + time equations at each reading?
Can you use this data to go back to, for example, a stream of timestamps
and add a correction factor to the timestamps to get improved time
accuracy on historical data?
--
Chris Caudle
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To further Chris' question if I took data say on the same day every year
can I measure which way my tectonic plate is moving and how far?
On 5/3/2018 10:17 AM, Chris Caudle wrote:
On Wed, May 2, 2018 11:36 pm, Mark Sims wrote:
have Heather do all the receiver configuring, data
capture, and RINEX making...
I have been following along with the update messages, and this seems like
really cool improvements to the underlying infrastructure pieces that a
lot of us use (Lady Heather, support for more GPS modules, etc.), but I
am having trouble putting all the pieces together.
Having submitted the files to some post-processing server, do you only get
back information showing your position to some small number of
centimeters, or does it send back a stream of values showing the
corrections to the full position + time equations at each reading?
Can you use this data to go back to, for example, a stream of timestamps
and add a correction factor to the timestamps to get improved time
accuracy on historical data?
--
Dave
Manuals@ArtekManuals.com
www.ArtekManuals.com
This email has been checked for viruses by Avast antivirus software.
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Hi
If you have a very good survey grade receiver and take a long enough data set, yes you can
watch your location drift in some parts of the world. In most locations, fixes a few years apart
would be a better bet.
Indeed this does get a bit far from the world of timing …… The distances involved are nasty
small. Even for the location of your telescope when doing astronomical timing observations,
they are unlikely to matter on a yearly basis. At some point the error is “to small to matter” ….
Bob
On May 3, 2018, at 11:12 AM, Artek Manuals Manuals@ArtekManuals.com wrote:
To further Chris' question if I took data say on the same day every year can I measure which way my tectonic plate is moving and how far?
On 5/3/2018 10:17 AM, Chris Caudle wrote:
On Wed, May 2, 2018 11:36 pm, Mark Sims wrote:
have Heather do all the receiver configuring, data
capture, and RINEX making...
I have been following along with the update messages, and this seems like
really cool improvements to the underlying infrastructure pieces that a
lot of us use (Lady Heather, support for more GPS modules, etc.), but I
am having trouble putting all the pieces together.
Having submitted the files to some post-processing server, do you only get
back information showing your position to some small number of
centimeters, or does it send back a stream of values showing the
corrections to the full position + time equations at each reading?
Can you use this data to go back to, for example, a stream of timestamps
and add a correction factor to the timestamps to get improved time
accuracy on historical data?
--
Dave
Manuals@ArtekManuals.com
www.ArtekManuals.com
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
time-nuts mailing list -- time-nuts@febo.com
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and follow the instructions there.
On 5/3/18 8:09 AM, Bob kb8tq wrote:
Hi
The sites are aimed at improving position information. To the degree that having an
accurate location for your antenna improves timing, simply doing that is a step forward
for your GPSDO.
Most sites also will give you information that shows the timing solution at a given point
in time. To the degree that you can connect that to prior data it could be useful. There
are more than a few steps involved in getting this to work.
The JPL processing chain gives not only more accurate positions vs time,
but also estimates of clock error vs time, if that's in the data stream
being processed.
On 5/3/18 8:28 AM, Bob kb8tq wrote:
Hi
If you have a very good survey grade receiver and take a long enough data set, yes you can
watch your location drift in some parts of the world. In most locations, fixes a few years apart
would be a better bet.
Indeed this does get a bit far from the world of timing …… The distances involved are nasty
small. Even for the location of your telescope when doing astronomical timing observations,
they are unlikely to matter on a yearly basis. At some point the error is “to small to matter” ….
Bob
Unless you live on a plate boundary and have to keep repairing your
fences and foundations <grin>
On 5/3/18 8:28 AM, Bob kb8tq wrote:
Hi
If you have a very good survey grade receiver and take a long enough data set, yes you can
watch your location drift in some parts of the world. In most locations, fixes a few years apart
would be a better bet.
Indeed this does get a bit far from the world of timing …… The distances involved are nasty
small. Even for the location of your telescope when doing astronomical timing observations,
they are unlikely to matter on a yearly basis. At some point the error is “to small to matter” ….
Bob
Hit send too quick..
But more realistically, this is kind of a time-nutty sort of goal - to
be able to make measurements to a precision where you can match your
measurements to a nearby geodetic station with "official" measurements.
All the usual time measurement with GPS issues come into it - multipath,
the diurnal variations, solid earth tides.
It's what everyone says - getting to meters or 10s of ns - easy -
getting to tenths of ns or cm, significantly harder.