[teqc] Single avg position (cart or geo) as output?

Andrew Miner minera at Geology.cwu.EDU
Thu Dec 1 10:53:44 MST 2005


Thanks--that clarifies things a little.  Don't worry, we're not building
bridges or anything, just using this as initial input for gipsy.  +pos
works nearly all the time, and +ap can only improve on this.

I still am mildly curious why +eep used in combination with +ap or +pos
gives a different answer, but presume it could be due to an extra round of
rounding or something.

Also, what exactly is "qc header position" in the qc output?

> Jim's comments are right on target.  (More like two bits worth. ;)
>
> Someday, maybe, the point positioning might be upgraded to do all the
> parts for a better position, including even reading SP3 files.  But at
> the moment there really isn't much motivation to do that, since there are
> so many on-line processing paths (like auto-gipsy).  And the teqc pp
> still does suffice for what it was intended.
>
> --lou
>
>> The point position from teqc is a pretty rough one, I think it just
>> uses (P1+P2)/2 as the pseudo-range observation.  It is really only
>> meant as a rough estimate to make sure there were no blunders (i.e.  the
>> data is from another site than expected).  Use the +pos option if  you
>> want a quick and dirty a priori -- +ap will average positions, it  may
>> be a little better, but I still would not trust it that much.   Use the
>> eep options if you suspect that there are multiple  occupations (stop
>> and go) or that the data is actually kinematic.
>>
>> If you want a good a priori, then you should use something like  CODSPP
>> (Bernese lingo) to generate a least squares estimate for a  single
>> position over the entire occupation.  And if you can use IGS  orbits and
>> clocks, you should get a position to a few decimeters.   The a priori
>> from TEQC +pos would be just fine for this sort of  estimate.
>>
>> My 2 cents.
>> Jim
>>
>> On Nov 30, 2005, at 5:38 PM, Andrew Miner wrote:
>>
>>> Lou (et al.)--
>>>
>>> Now I see that in addition to the +ap flag there are also some +eep
>>> ("every epoch position") flags. Used in various combinations, +pos,
>>> +ap,
>>> and +eep yield a variety of positions, while +eepx and +eepg seem  to
>>> be
>>> meant to be used alone to generate lists of epochs with positions.
>>>
>>> (See attached)
>>>
>>> Any comments on the different results or recommendation of a flags to
>>> generate a maximally accurate position to use as initial input for
>>> processing?
>>>
>>> On Thu, 2005-08-18 at 13:31 -0600, Lou Estey wrote:
>>>
>>>> Steve's suggestion is AOK, but there are some other things
>>>> that might be of interest.  Michael was asking for a mean position,
>>>> and normally teqc just turns the last point position it
>>>> determined.  There is an option (that I haven't tested in
>>>> years) "+ap" which is supposed to report the average point
>>>> position, i.e. include this option when doing +qc and the
>>>> lines that Steven pointed out should have the mean position
>>>> (which is still a low-precision point position).  But, if
>>>> you just want some idea of the position ASAP, do a +qc as
>>>> Steven suggested but also include "+pos", which should
>>>> terminate teqc and report a low-precision point position (same
>>>> format as below) for the antenna as soon as one is determined.
>>>>
>>>> To summarize:
>>>>
>>>> +qc -nav RINEX_NAV      : qc with last point position
>>>> +qc -nav RINEX_NAV +ap  : qc with average (mean) point position
>>>> +qc -nav RINEX_NAV +pos : first point position & terminate
>>>>
>>>> hth,
>>>> --lou
>>>>
>>>> Mullins, Steven wrote:
>>>>
>>>>> Michael,
>>>>>
>>>>> A standard TEQC summary contains the following lines:
>>>>>
>>>>>   antenna WGS 84 (xyz)  : 644013.2777 -5069344.4809 3804951.2706 (m)
>>>>>   antenna WGS 84 (geo)  : N  36 deg 51' 20.62"  W  82 deg 45' 35.59"
>>>>>   antenna WGS 84 (geo)  :   36.855728 deg   277.240114 deg
>>>>>           WGS 84 height : 595.1376 m
>>>>> |qc - header| position  : 36 m
>>>>>
>>>>> just run TEQC +qc and give a nav and obs file.
>>>>>
>>>>> Steve
>>>>>
>>>>> -----Original Message-----
>>>>> From: teqc-bounces at ls.unavco.org [mailto:teqc-
>>>>> bounces at ls.unavco.org]On
>>>>> Behalf Of Michael Scharber
>>>>> Sent: Wednesday, August 17, 2005 2:36 AM
>>>>> To: teqc at unavco.org
>>>>> Subject: [teqc] Single avg position (cart or geo) as output?
>>>>>
>>>>>
>>>>> Hi There,
>>>>>
>>>>> Can someone point me to, or show me, how one can use teqc to  produce
>>>>> a
>>>>> simple mean position (cartesian or geographic) from a single  input
>>>>> raw or
>>>>> RINEX GPS data file.....based on the data, of course, not header
>>>>> information.  Position can be low precision - I don't care.
>>>>>
>>>>> Any advice would be greatly appreciated.
>>>>>
>>>>> Thanks,
>>>>>
>>>>> Michael
>>>>>
>>>>> ps. By "produce" I mean someone spat out to stderr or stdout that
>>>>> can be
>>>>> captured by another program.
>>>>>
>>>>> *******************************************************
>>>>>            Michael Scharber
>>>>>      Scripps Institution of Oceanography
>>>>>      Institute of Geophysics and Planetary Physics
>>>>>      8785 Biological Grade
>>>>>      IGPP Room 4212
>>>>>      La Jolla, CA 92037
>>>>>
>>>>>          mscharber at gpsmail.ucsd.edu
>>>>>      (858)534-1750
>>>>> *******************************************************
>>>>
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