instruction manual standard positioning service (sps...
TRANSCRIPT
Instruction Manual
Standard Positioning Service (SPS) Online
FCT/UNESP
Bruno C. Vani, Joao F. Galera Monico and Milton H. Shimabukuro
v. 2017-10-20
1
Summary
About the SPS Online Software................................................................................3
Main features...........................................................................................................4
Instructions..............................................................................................................4
Step 1 – Input RINEX (upload)..............................................................................6
Step 2 – Choose the GNSS System and Observable.............................................7
Step 3 – Setup elevation mask and Application of Models...................................8
Step 4 – Output configuration..............................................................................8
Processing Examples...............................................................................................9
Example 1: Processing RINEX v.2.11 – GPS Data..................................................9
Example 2: Processing RINEX v.2.11 – Galileo Data...........................................12
Example 3: Submitting observation and navigation RINEX v.3.03 – Galileo Data
...........................................................................................................................13
Final Remarks.........................................................................................................14
2
About the SPS Online Software
This document present Instructions for processing GPS or Galileo data with
the Software Standard Positioning Service (SPS) Online.
This scientific software was developed and has been maintained at Faculty
of Science and Technology - Univ. Estadual Paulista (FCT/UNESP) – Presidente
Prudente/Brazil, in the context of the Space Geodesy Study Group and Graduate
Programme in Cartographic Sciences.
This software is designed to be a scientific tool with applications to
research and educational purposes. Error-free solutions are not warranted. Please,
contact the authors to provide suggestions, implementations or to report any bug
or inconsistency. Corresponding authors:
• Bruno C. Vani ([email protected])
• Joao F. Galera Monico ([email protected])
• Milton H. Shimabukuro ([email protected])
This software is available online at http://is-cigala-calibra.fct.unesp.br/pps
(or via the section of online softwares of the Space Geodesy Study Group
website).
The first version of the Software was released in 2012 and was capable to
process only GPS C1 data. Thereafter, the software has been maintained and
updated following the advances in the GNSS technology, such as the emerging of
Galileo satellites and the new standards for RINEX files to supply new observation
types.
3
Main features
The SPS Online is designed to simulate the real conditions experienced by
several non-assisted / non-professional GNSS units. The processing is made only
considering broadcast products (ephemeris and satellite clock corrections).
The main features of the SPS Online include:
• Read user’s input RINEX files (the users can upload RINEX files
through a graphical user interface);
• Support to RINEX v. 2.11 and 3.xx: currently, the support is updated
according to RINEX v.3.0.3 specification;
• Process GPS or Galileo pseudorange observables;
• Apply broadcast products only (ephemeris and satellite clock
corrections): the system download broadcast ephemeris file from IGS
(as well as to read navigation files in RINEX format submitted by the
user);
• Possibility to apply global models for troposphere (Hopfield) and
Ionosphere (Klobuchar);
• Provide a high-level report, including the step-by-step computation to
support research and educational purposes.
A scientific paper about the software is available (in portuguese) at the
Brazilian Maganize of Geomatics (http://dx.doi.org/10.3895/rbgeo.v2n1.5441),
including theoretical background and discussions about the implementations.
Please, consider to include a citation if you apply any output of this software in
scientific research.
Instructions
The english version of the main graphical user interface is shown in Fig. 2
and will be explained in the next subsections.
4
5
Fig. 1: Graphical user interface to upload data and setup processing
configurations..
Step 1 – Input RINEX (upload)
There are five different options to upload input RINEX data for processing:
a) Upload observation RINEX v.2.11 file: the maximum file size is 10MB.
If necessary, the file can be compressed within the “.zip” format.
b) Upload observation and navigation files (RINEX v.2.11): in this case,
the files must follow the convention for file naming (according to
RINEX v.2.11 specification). The both navigation and observation files
must be compressed within the “.zip” format before submission.
c) Upload observation RINEX v.3.xx file: the maximum file size is 10MB. If
necessary, the file can be compressed within the “.zip” format.
d) Upload observation and navigation files (RINEX v.3.xx): in this case,
the files must follow the convention for file naming (according to the
RINEX v.3.03 specification). The both navigation and observation files
must be compressed within the “.zip” format before submission.
e) Automatic upload – Brazilian RBMC Network Data: specify station
name, year and day of year. The RINEX file will be automatic loaded
from the RBMC Server. This option can be slow because the RINEX file
need to be retrieved via FTP.
If only the observation RINEX file is provided, the navigation data
(broadcast ephemeris) will be automatically downloaded from the IGS
repositories.
Notice that only the “.zip” format is accepted when submitting
compressed files. Other compression types, such as “.gz”, “.rar” and “.7z” can not
be handled and will result in errors.
Remark: the approximated coordinates (present in the header of the
observation RINEX file) will be applied for processing and used as reference
coordinates to produce graphical results (plots with positioning discrepancies
between the achieved solution epoch-by-epoch and the reference coordinates). If
6
the observation RINEX file doesn’t contain approximated coordinates, the first
achieved solution will be used as reference coordinates.
Step 2 – Choose the GNSS System and Observable
There are options to choose between processing data from GPS or Galileo.
According to the chosen option (as well as the version of the RINEX file as chosen
in Step 1), the available observables will be dynamically changed in the
observables list. Ex: If you choose “Upload observation RINEX file (v.2.11)” in the
Step 1 and choose the GNSS System “Galileo” in Step 2, the observables list will
be refreshed with the available observables for this scenario (in such case, C1, C5,
C7, C8 or C6) (see Fig. 2). When processing data from RBMC, the system will
automatically refresh the observables list with the RINEX v.2.11 observables.
7
Fig. 2: Select observable according to RINEX version (v.2.11 or 3.xx) and GNSS
System (GPS or Galileo).
Step 3 – Setup Elevation Mask and Application of Models
The default elevation mask is 5°, but one can setup different elevation
masks such as 10°, 15° or 20° for performance evaluation. Please notice that
increasing the elevation mask will reduce the number of satellites available and
may cause loss of availability if less than 4 satellites are available at a given
epoch.
Concerning the application of models, the user can choose between to
apply (or not) Global Models for correcting ionospheric and tropospheric
refraction. The following models are available:
a) Ionosphere (Klobuchar Model): Just mark the checkbox to apply this
model. Although designed to operate with GPS, the Klobuchar Model
can be used with Galileo as well. The Klobuchar Model demands
coefficients (ion-alpha and ion-beta) to be proper applied. If
necessary, an additional navigation file will be automatically
downloaded to obtain the alpha and beta coefficients;
b) Troposphere (Hopfield Model): Just mark the checkbox to apply this
model. Remark: the Hopfield Model demands input information about
the atmospheric conditions. There are input fields to input
temperature (C°), pressure (mbar) and relative humidity (in
percentage). These fields are optional. If not provided, the model will
input values assuming a default atmosphere.
Step 4 – Output configuration
In this step, there are options to delimit the processing, setup processing
step and decide whether to include a step-by-step report with one computation
example.
The options to delimit the processing epochs allow to setup the “start” and
“end” time for processing the observations in the observation RINEX file. If not
8
provided, the system will automatically consider to process between 00:00:00 to
24:00:00.
The “step” configuration allows to reduce the sampling output of the
results. Ex: if the RINEX file is sampled at 15s, one can choose step=4 to
processing just one epoch by minute. The default step configuration is step=1,
e.g., to process all epochs from the RINEX file.
Finally, the option to “include one step-by-step computation example”
enables the creation of a high-level detailed report demonstrating how the
software works. This report will include each step of the processing, such as
selecting the observables in the RINEX file, estimating satellites position, setup
the matrixes, performing the least-squares adjustment and obtaining the results.
Typically, this report will be generated only for the first processed epoch.
Processing Examples
After to setup the configurations, please insert your email address in the
proper feld and just click OK to process data. Your email address is required only
for support purposes.
The processing response time varies according to the upload time, file size
and the output sampling rate. It’s not necessary to refresh the page while the
process is running. If the page expires, please, try to upload the file again and
click to start a new processing.
Example 1: Processing RINEX v.2.11 – GPS Data
In this example, RINEX v.2.11 from the IGS station “SPTU” was processed
with GPS observable “C1” (DOY 200/2017). The Klobuchar and Hopfield models
were applied for mitigating ionospheric and tropospheric refraction, respectively.
The output was delimited between “20:00:00” and “21:00:00”. When the
9
processing is finished, the response time will be displayed and a link will be
available to check the results (see Fig. 3).
Click “View Results” to check the report with graphical results and
additional information, or click “View step-by-step example” to check the detailed
report including the numeric computation.
In the graphical report, the applied configuration are displayed. There is a
link to download the numeric results (in “.txt” format), as well as plots for
graphical representation of the solutions. One example is presented in Fig. 4,
there one can see header of the report and the plot of discrepancies between the
approximated coordinates and the achieved ones.
10
Fig. 3: Processing is finished.
In the step-by-step report, the numerical results for the first epoch in the
results data set is displayed. One can use the index in the right panel to navigate
on the steps of the processing. The first step is to read the observables in the
observation RINEX. The last step is to show the achieved results (XYZ), precision
and errors.
11
Fig. 4: Results in the graphical report.
Example 2: Processing RINEX v.2.11 – Galileo Data
In this example, the same data as presented in example 1 is processedwith Galileo data (SPTU, DOY 200/2017, C1 observable). The Hopfield andKlobuchar models were applied.
12
Fig. 5: First steps in the extensive step-by-step log. One can use the right-block to
navigate between the steps.
Example 3: Submitting observation and navigation RINEX
v.3.03 – Galileo Data
In this example, a RINEX file in the v.3.03 is processed. In this example, weconsider both observation and navigation files submitted by the user. Followingthe RINEX v.3.03 file naming convention, the files are named as:
• pru100____R_20172000000_01H_60S_MO.rnx (mixed observation file);
• pru100____R_20172000000_01H_EN.rnx (Galileo navigation file).
13
Fig. 6: Example of graphical results from Galileo processing.
The both files can be compressed within the “.zip” format and thensummited in the graphical interface.
Final Remarks
This document presented instructions for using for the scientific softwareStandard Positioning Service Online, developed at FCT/Unesp, available online at .This software is designed to be a scientific tool being available without anywarranty for research and education purposes. Please, contact one of thecorresponding authors to provide suggestions, implementations or to report anybug or inconsistency.
14
Fig. 7: Processing RINEX v.3.03. The top plot shows the “.zip” file content. The
bottom plot shows the corresponding upload option.