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

James Johnson jjohnson at ucar.edu
Wed Nov 30 17:58:15 MST 2005


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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