Question

Hello!

I am leading a scientific project to evaluate the influence of the 24th Solar Maximum on GNSS measurements in polar regions. For that purpose I participated in the 2012/2013 Bulgarian Antarctic expedition on the Bulgarian base "St. Kliment Ohridski" on Livingston island, Antarcica.

I did a GNSS measurements for 10 days on the geodetic reference point KOH1, located in the vicinity of the base. This point has been measured with Trimble R4 GNSS receiver. I am trying to make a VTEC maps with the data from this year in order to compare it with data from 1998 - the year in which this point was established and the only time it had been measured before now.

As a start, I am processing data from three stations from the day 359/ year 2012 (24 December 2012). The stations are the already mentioned KOH1, as well as two IGS stations in the area - OHI2 and PALM. The procedure that I implement is as follows:

ResCor on the RINEX data from the three stations:

ResCor

ResCor -IFkoh13590.12o --nav brdc3590.12n -OFkoh13590.rc --RxXYZ 1453260.3820,-2554435.0860,-5641770.0930 -TN30.0 -HDf --Callow --IonoHt 350 -AOEL -AOAZ -AOLA -AOLO -AOSP -AOSR

ResCor -IFohi23590.12o --nav brdc3590.12n -OFohi23590.rc --RxXYZ 1525811.1000,-2432479.1000,-5676166.0000 -TN30.0 -HDf --Callow --IonoHt 350 -AOEL -AOAZ -AOLA -AOLO -AOSP -AOSR

ResCor -IFpalm3590.12o --nav brdc3590.12n -OFpalm3590.rc --RxXYZ 1192671.9920,-2450887.7060,-5747096.1840 -TN30.0 -HDf --Callow --IonoHt 350 -AOEL -AOAZ -AOLA -AOLO -AOSP -AOSR

I am using the settings founded in the /gpstk/apps/ionosphere/example/preprocess.pl (lines 52-57), which are:

"# make up ResCor options

#decimate to 30 second data, fill output header

push @opt, "-IF$rawfile -OF$obsfile";

push @opt, "-TN30.0 -HDf -HDm$stationID --Callow --IonoHt 350";

push @opt, "-DOL1 -DOL2";

#push @opt, "-DOC1 -DOP1 -DOP2";

push @opt, "-DOD1 -DOD2 -DOS1 -DOS2";

push @opt, "-AOEL -AOAZ -AOLA -AOLO -AOSR";"

I am not deleting any data though (I am not using the DO commands).I am getting three extended RINEX files.

Now I run the IonoBias program:

IonoBias

IonoBias --input koh13590.rc --input ohi23590.rc --input palm3590.rc --nav brdc3590.12n --datafile ATallstations.fil --MinPoints 24 --MinTimeSpan 12 --MinElevation 6 --MinLatitude -65 --MaxLatitude -60 --MinLongitude 290 --MaxLongitude 300 --TerminOffset 20 --IonoHeight 350 --biasout satbias.txt

I am using an area, bounded by Lat (-60,-65 deg) and Lon (290,300 deg), which is corresponding to the area of the three polar GNSS stations.

QUESTION 1: WHAT IS THE FORMAT OF THE DATA IN THE OUTPUT FILE (--datafile)? I am getting this output:

3 3 Number (max, good) stations in this file

010100100001000000010000000000001

010100000011000100010000000000001

010100100010000110010010101000100

Npt 599 Sta koh1 LLH -62.4842 299.6363 -4.6616

1720 96960.0 -60.45900 -135.87576 0.83 0.000 1 22 1

1720 96990.0 -60.47600 -135.73776 0.83 0.000 1 22 1

1720 97020.0 -60.49200 -135.59976 0.83 0.000 1 22 1

1720 97050.0 -60.50900 -135.46276 0.83 0.000 1 22 1

I can see that it beggind with GPSWeek, SecondOfWeek, then what? Probably Latitude, then...?

QUESTION 2: WHAT IS THE FORMAT OF THE DATA IN THE SATBIAS.TXT FILE (-- biasout)? I am getting this output:

IonoBias, built on the GPSTK ToolKit, Ver 1.0 6/25/04, Run 2013/04/08 02:56:41

24 Number of SPR biases

BIAS 1 koh1 G06 0 37.264177 6.370e-01

BIAS 2 koh1 G03 0 36.809456 5.654e-01

BIAS 3 koh1 G19 0 38.206486 4.711e-01

With the output data from the previous steps I am running the TECMAps software:

TECMaps

TECMaps --input koh13590.rc --input ohi23590.rc --input palm3590.rc --nav brdc3590.12n --RxLLH -62.,300.,0.0 --log tec.log --BaseName out/igs --Biases satbias.txt --IonoHeight 350 --UniformSpacing --OutputGrid --GnuplotOut --NumLat 40 --NumLon 40 --BeginLat -60 --BeginLon 290

QUESTION3: RxLLH - I am giving approximate position of the area that I want to investigate, the program will not accept RxLLH inputs of all three stations. IS THIS CORRECT?

QUESTION 3.1: AM I USING THE SP OR THE SR TEC VALUES? I OUTPUTTED BOTH IN THE EXTENDED RINEX FILES, BUT I AM NOT SURE WHICH ONE THE IONOBIAS USES?

I am getting as output in the OUT folder a collection of igs.0001-2880 files, as well as a igs.LL file:

Sample from igs.0001:

-62.970 274.564 0.000

-62.453 275.022 0.110

-61.933 275.465 0.256

Sample from igs.LL file:

-69.903 266.052 6862017.778 -162352.798 -2352312.666 -6444187.667 0 0

-69.433 266.824 6849688.859 -133330.314 -2402581.082 -6413116.608 1 0

-68.959 267.565 6837971.643 -104307.830 -2452849.499 -6382045.550 2 0

QUESTION 4: WHAT IS THE OUTPUT FORMAT OF THESE TWO FILES? Maybe the first two columns are the Latitide and Longitude of the IPP? What about the rest?

QUESTION 5: WHICH COLUMNS SHOULD BE USED FOR SURFACE PLOT WITH GNUPLOT? I am running in gnuplot:

splot "igs.LL" u 1:2:4

IS THIS CORRECT? WHERE IS THE VTEC DATA STORED AND WHAT IS THE BEST WAY TO PLOT THE MAPS AND GET THE FINAL RESULTS?

Thank you very much for your help. The software is quite useful, but I would really appreciate your answeres on the stated QUESTIONS.

Sincerely,

Assist. Prof. Asparuh Kamburov, Ph.D

University of Mining and Geology

Bulgarian Antarctic Institute

-- AsparuhKamburov - 08 Apr 2013

Answer

ALERT! If you answer a question - or have a question you asked answered by someone - please remember to edit the page and set the status to answered. The status is in a drop-down list below the edit box.

Dr. Kamburove,

We want to thank you for your interest in the GPS Toolkit.

Unfortunately, due to limited staff, we do not have the capability to answer all questions as quickly as desired. Since the segment of the GPS Toolkit you refer to is older, it will require quite a bit of time and focus to provide an appropriate answer. Please be patient, as it will be added to the GPS Toolkit priority queue.

In the meantime, I will leave the question unanswered, and note that a majority of the questions can be answered both by the community and by becoming familiar with the code. As an open-source software library, we at ARL have provided the base software and encourage users to add supplemental comments, functionality, improvements, and submit these improvements for use by the rest of the GPS Toolkit community.

-- BryanParsons - 08 Apr 2013

Updated

Dr. Kamburove,

In error, I set the status of the question as "answered". I have also reworded my past response, in order to let you know we are not ignoring your question.

My apologies,

-- BryanParsons - 17 Apr 2013 No such template def TMPL:DEF{PROMPT:supportquery}
Topic revision: r4 - 12 Jun 2015, UnknownUser
 

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