How to use the Java Display Applet

Click on the figures to get a bigger image.



figure 1. The Applet in use.

The display is a Java Applet that produces real-time data plots from the SuperDARN radars equipped with internet connections. When started the applet creates a button on the web page for each radar providing a data that can be displayed.

figure 2. The Display buttons.

Clicking on a button will start the display for that radar and open the main control window shown in figure 3. The window is divided into two sections. At the top is a line that shows the current status of the internet connection to the radar. Beneath this are a series of buttons that control the internet connection and open the various plot windows.

When the display is first started it will automatically attempt to open a link to a radar and the status line will read "Connection Open". If the connection fails this line will change to read "Connection Failed".

As data is received from the radar, the status line will change to record the total number of data packets processed by the applet.

Occasionally due to band-width restrictions or glitches on the Internet the link will become broken and the status line will read "Connection Reset". The user can try to re-establish the connection using the "Open Connection" button.

figure 3. The Control Window.

Status Bar Window

figure 5. The Status Bar Window.

The first button on the control window will open the "Status Bar" window which shows detailed information about the operation of the radar including the numbe of pulse sequences transmitted per integration and the number of attenuation level being used.

Geographic Plot Window

figure 6. The Geographic Plot Window.

The second button on the control window will open the "Geographic Plot" window which plots data using a stereographic map projection showing the field of view of the radar. The current UT time is shown at the top of the window and the beam, frequency and noise level are shown at the bottom. Clicking on the "Toolbox" button will open the toolbox window for the plot shown in figure 7.

figure 7. The Geographic Plot Tool Window.

The three buttons at the top left hand side of the tool box select which parameter will be plotted, either power in decibels, doppler velocity in m/s, or spectral width in m/s.

The switch labelled "Mark Key" switches on and off a grid that divides the colour key into ten equal segments while switch labelled "Linear Key" restricts the number of colours use in the plot to 10

The swith labelled "Ground Scatter" switches on and off the coloring of ground scatter as grey.

The switch labelled "Meridian Marks" switches on and off the the meridian line markings on the geographic display. The longitude and latitude are marked at 10 degree intervals.

The switch labelled "Continents" will overlay a map on the geographic display and the final switch labelled "Filled Continents" will selects solid or outline continents.

The text field to the right of the label "Colour Scale Limit:" allows you to change the limits of the colour scale. Entering a new value will redraw the plot using the new limits of the scale.

The switches below the label "Range Grid:" allow a grid to be overlayed on the radar field of view, marked in 5, 10 or 15 range gate intervals.

The menu buttons at the bottom right of the toolbox allow you to change the colours that the range grid, meridian markings and coastline are plotted in.

Time Plot Window

figure 8. The Time Plot Window.

The third button on the control window will open the "Time Plot" window which shows a time series of the scatter observed along a single beam direction. The current UT time is shown at the top of the window along with the beam number plotted.

The two buttons maked "-" and "+" zoom the plot in and out. The "Toolbox" button will open the toolbox window for the plot shown in figure 9.

figure 9. The Time Plot Tool Window.

The three buttons at the top left hand side of the tool box select which parameter will be plotted, either power in decibels, doppler velocity in m/s, or spectral width in m/s.

The switch labelled "Mark Key" switches on and off a grid that divides the colour key into ten equal segments while switch labelled "Linear Key" restricts the number of colours use in the plot to 10

The text field to the below the label "Key Limit:" allows you to change the limits of the colour scale. Entering a new value will redraw the plot using the new limits of the scale.

The swith labelled "Ground Scatter" switches on and off the coloring of ground scatter as grey.

The menu button at the bottom right of the toolbox allow you to change the colours that the grid markings are plotted in.

Fan Plot window

figure 10. The Fan Plot Window.

The fourth button on the control window will open the "Fan Plot" window which plots data using a simple fan-shaped representation of the radar. The current UT time is shown at the top of the window and the beam, frequency and noise level are shown at the bottom. Clicking on the "Toolbox" button will open the toolbox window for the plot.

figure 11. The Fan Plot Tool Window.

The three buttons at the top left hand side of the tool box select which parameter will be plotted, either power in decibels, doppler velocity in m/s, or spectral width in m/s.

The switch labelled "Mark Key" switches on and off a grid that divides the colour key into ten equal segments while switch labelled "Linear Key" restricts the number of colours use in the plot to 10

The text field to the below the label "Key Limit:" allows you to change the limits of the colour scale. Entering a new value will redraw the plot using the new limits of the scale.

The swith labelled "Ground Scatter" switches on and off the coloring of ground scatter as grey.

The switches below the label "Range Grid:" allow a grid to be overlayed on the radar field of view, marked in 5, 10 or 15 range gate intervals.

The menu button at the bottom right of the toolbox allow you to change the colours that the range grid is plotted in.

Hot Box Window

figure 12. The Hot Box Window.

The fifth button of the control window will open the "Hot Box" window which records information about a particular point in the Radar filed of view. The point is selected by clicking the left mouse button over a data point in any of the plot windows. The time,beam,range and geographic co-ordinates of the point are recorded in the window. The status of the ground scatter flag (Gflg), the numeric value of the parameter plotted, the noise level and the transmitted frequency are also recorded.