Graphing Sonde data

An atmospheric probe (sonde) carried aloft by a weather balloon radioes data to its ground station. We will access some of that data and use it to make a plot of air temperature at different altitudes.

This process consists of four basic steps: copying the data to a plain-text file, converting the text file to a spreadsheet file, plotting the data, and saving the plot to a graphics file.

Make the plain-text file

1. Click and drag in the data window to select the table of measurements.
2. Create a plain-text file to take the data. I like to use the simple text editor program Notepad. To open it, click on the "Start" icon at the lower left of the computer screen, then mouse over "All Programs > Accessories > Notepad".
3. Go back to the data window that displays the sonde readings. Select the data table with headings by clicking and dragging. Copy the data to the clipboard by hitting "Ctrl-C".
4. Move your cursor back to the Notepad window. Paste the data table into it by clicking "Ctrl-V".
5. Delete the rows of hyphens that set off the column labels.
6. Provide a unit for the second row of the first column: type "#" at the first character of the second row.
7. save the file as plain text. Click on "File" in the menu bar, select "Save As…", and navigate using the "Save in:" field to your file storage area (such as your student disk space). For the file name, use the name of your data location (e.g. “Paris”). This saves the file to your selected location.

Make a spreadsheet file

1. Open Excel.
2. Within Excel, open the text file you just saved. First, you need to tell Excel to look for a text file, since it normally ignores them. Set "Files of Type" to "All Files" or "Text files". This brings up Text Import Wizard.
3. Under "Choose the file type that best describes your data", select "Fixed width", and click "Next >".
4. Verify that column breaks are where you want them, and click "Next >"
5. for "Column Data Format," choose "General," then click "Finish"
6. The file opens in Excel in tabular form.

Plot the Data

1. Select the data part (the numbers, not the headings) of the adjacent columns "HGHT" (altitude in meters) and "TEMP" (temperature in Celsius).
2. From the top (menu) row, click on the "Insert" tab.
3. Choose the last option, "Scatter with Straight Lines". This makes a plot, but probably with the axes reversed from what you want.
4. If the "Design" tab not already active, click on it, then "Select Data".
5. To switch the x and y axes, Edit Series 1. Click on "Edit"box, then switch the column indices for the "Series X values" and "Series Y values".
6. Find the plot in the Excel window. It could be anywhere.
7. Click the "Layout" tab in top menu bar.
8. In the "Labels" box, select "Chart Title," and select "Above Chart".
9. Enter the name of the sonde location (e.g.“Paris”) in title text box.
10. Select "Axis Titles," make the horizontal axis title "Temp (C)". Make the vertical axis title "Height (m)".
11. Click on "Legend" and select "none".
12. Save the Excel file. Click on the circular MS icon in top left, and select "Save As" from the menu.
13. In the "Save as type" field, select "Excel Workbook" or Excel 97-2003 Workbook".

Save to a graphics file

1. Select the entire plot and resize it so that it is a good display size.
2. Copy it to the clipboard by hitting "Ctrl-C".
3. From "Start" menu, select "All Programs" > "Accessories" > "Paint".
4. Paste the graphic into the Paint window using "Ctrl-V".
5. Resize the image area to fit the plot area by clicking and dragging on its corners.
6. Save the graphic. In the menu bar, select "File" > "Save As";
7. Pick the folder to save the file in (use your student data storage area).
8. Name it something easy to understand like "location_sonde". For instance, if your sonde was released from Paris, call the file "Paris_sonde".
9. In "Save as type" try "JPEG". (You can experiment with different file types to see what the results look like.)