[teqc] Explain some symbols in plot file
lou at unavco.org
Thu Dec 14 14:42:14 MST 2006
> Hi my name is Mike and Im a student at Slovak Technic University in
> Bratislava. Im finishing UNI this summer and now Im doing on my
> graduation theses . I have done quality check. And in final report
> graph there are three symbols –dn,+dn +10 I don’t know what they are?
> Would you be so kind and send me the explanation of these three symbols
> by email?
For qc full runs, the "Obs" line is replaced by four lines, labeled "-dn", "+dn", "+XX", and "Pos". The "+XX" line is the one most like the
qc lite "Obs" line; the XX is replaced by the elevation mask in degrees (rounded to the nearest degree) and indicates the maximum expected
number of SVs that are above the elevation mask, according to the supplied ephemerides, again using a hexidecimal notation. The difference
between the qc lite "Obs" line and the qc full "+XX" line is the difference between reality and theory: "Obs" shows what was seen, where
"+XX" shows what could have been seen (above the elevation mask).
The discrepancy between reality and theory is recorded in the "-dn" and "+dn" lines, which are the SV tracking discrepancy counts, and
record the two bounds of the discrepancy. They can be thought of as the "good new/bad news" to the number of SVs not tracked. The line "-dn"
records the minimum discrepancy of all observation epochs for that time bin while the line "+dn" records the maximum discrepancy of all
observation epochs for that time bin. The discrepancy count is also shown in hexidecimal notation, with (blank) for 0.
For the discrepancy lines to work correctly, the option -max_rx_SVs must be set correctly. This states the maximum number of SVs that are
capable of being tracked by the receiver, and currently has a default value of 12. If a complete observation gap occurs with qc full, a
group of c characters will be shown (c is hex for 12), at least on the "+dn" line, and if the gap is large enough, on the "-dn" line as well.
Louis H. Estey, Ph.D. office: [+001] 303-381-7456
UNAVCO, 6350 Nautilus Drive FAX: [+001] 303-381-7451
Boulder, CO 80301-5554 e-mail: lou unavco.org
WWW: http://www.unavco.org http://jules.unavco.org
"If the universe is the answer, what is the question?"
-- Leon Lederman
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