COMPUTER AIDED THRUSTER PERFORMANCE ANALYSIS

version: 0.8.3

by Geraldo Ribeiro
<geraldo-ribeiro@uol.com.br>
28 Oct 2001

What is the CATPA?

The main motivation for this project was the need of improving the quality of the reports to be delivered to the client.
The old system posesses good data acquisition capabilities, however, its data treatment performance is quite poor. Another problem was the data format, for that format had not been supplied by the actual maintenance team of Scopix® software.

This project intends to improve the treatment of the data acquired by Scopix® software making it easier and faster. The CATPA will supply exports to several file formats, allowing the post processing of the data for nearly all available software.

The best report feature is its format: It is in LaTeX2e to ensure the longevity of the generated files and the compatibility with any operating system.

What do I need to run CATPA?

Your system must be compatible with the following characteristcs.
    • In this version it is run under GNU/LINUX, but in the future it will be available to other operational systems.
    • Data vizualization is made by a openGL window.
    • The toolkit used to create the interface is the Fast Light Tool Kit.
    • The plot driver is the GNUplot.
    • The text formatting language is the LaTeX2e.

Homepage

This homepage is hosted on http://catpa.sourceforge.net.

Newsgroups & Lists

Some newsgroups are avaliable to supply the lastest information on the CATPA status.

To receive information about new releases, improvements and related information you can subscribe the catpa-announce@lists.sourceforge.net list.

Forums

  • Feature Requests - For requisition and discussion of new features to be added to CATPA.
  • CATPA Development Talk - Those contributing to the CATPA codebase can talk about issues, implementation, etc...
  • Feature Announcements - Announcements and tips for new features provided by CATPA. Monitor to get them via email.
  • CATPA i18n - CATPA Internationalization. Please monitor this forum if you can code/translate.

How to get the CATPA binaries?

In the project page (http://sourceforge.net/projects/catpa/) several versions of the binaries and user-guides are avaliable.

Installing the CATPA

On GNU/LINUX system just type
rpm -ivh catpa-X.Y.Z-1.i386.rpm
to install the version X.Y.Z.

Launching the main Application

To launch the main Application type catpa on an X teminal. The password window is shown to prevent the manipulation of classified data from non ``authorized'' users (in a multiuser system (like UNIX) several users share storage devices, Applications, etc.).

This password will limit the access to the test results and log the user activity.

The main window is shown after you input the right password.

Creating a new base

A base is a group of tests. Before manipulating the data you must create or open a test base.  To create a new base choose File menu, then choose New base... option or press Ctrl+n.

Then a dialog is shown prompting a file name.

Importing a test result to the base

After the creation of the base you must import some Scopix® test results to the base. To do this choose Import test from scopix... from the File menu or press Ctrl+i.

Go to the directory which contains the Scopix® test configuration, then click on Ok button. The name of the chosen test is shown on the Scopix test list.

When you click over the name of the test all measurements acquired in this test are shown on the Scopix measurements list.

Converting a raw file

Before you access the actual data (i.e., the physical measurements) you must extract the bit shift values from the raw file and convert them to float point format so that they will represent the physical measurements.

To convert the above data choose Convert raw file... option from the Test menu or press Alt+c.

Warning: This operation may take several minutes, depending on your hardware.

While the conversion is taking place the status will show information on the activity of the Application. After conversion, the message Conversion done is shown.

Viewing a measurement

This conversion of the raw file enables the Application to manipulate the data. Usually the first thing you want to do is to look at the measurement value.To do this, you just click on the measurement label in the Scopix measurement list box. A graphic showing all values for the selected measurement is presented.

Some information about the measurement is also displayed on the Text area.

The fast access to the measurement value at any point is supplyed through two features: a) a monospaced grid; and b) boxes for (X,Y) pair.

When you move the pointer over the Plot window the point coordinate is shown in the X and Y boxes.

Zooming

To see a particular area in the graphic you must click with the button 1 (left button) of your mouse and drag it over the chosen area.

Making a choice such as the one shown above yields:

If you click with the button 2 (middle, not right button) of your mouse or if you choose Axis setup... from the Graphic menu or if you press Alt+a, the zoom settings dialog box is shown.

This dialog box shows the actual view settings, allowing the user to set a new limit for the view.

Clicking the button 3 (right button) of your mouse over the Plot window accomodates the whole curve.

Shifting measurements

This Application supplies routines to apply shifts on the measurements.
Example: The EWT (External Wall Temperature) measurement was acquired in Celsius scale. To convert it to the Kelvin scale you must choose Apply shift... from the Measurement menu and fill the input box with the conversion factor 273.15.

Scaling measures

This Application supplies routines to apply scales on the measurement.
Example: The PT4501 (Cell Ambient Pressure) measurement was acquired in bar. To convert it to MPa you must choose Apply scale... from the Measurement menu and fill the input box with the conversion coefficient 0.1.

Drifting removal

An undesirable phenomenon called drift occurs on some signals. This phenomenon can be atenuated by choosing Drift remotion from the Measurement menu.

The original signal is shown below

Then the corrected signal

Pulse description

Choosing Write pulse description from the menu Report, a table describing the size of each pulse in the test is written on the report file.

A fragment of this table is presented below

The first column indicates the pulse number. The second ant third columns describe the beginning and ending of each pulse. The last column shows the duration of each pulse.

Measurement tables

This Application has a routine to print measurements with a regular preset step.
Example: Print PC, F, UV1, IV1, UV2 and IV2.

Select this measurement holding the Ctrl key and choose the Write table of selected measurements... from the Report menu. A dialog box is shown asking for some parameter.

This dialog starts with the beginning of the test (0.0 s), its ending and an arbitrary step (0.5 s). You may alter these values according to your convenience.

Special thanks