Using the TV Monitor (660 Systems Only)
If you have a 660 system, your video image is displayed in a virtual “TV” window in AugerMap. To open the TV window, click TV/Video in the System menu. When the TV window is opened, the TV comes on by default, and you will
see an image if your electron gun is on and your system settings are correctly set for imaging under the
current conditions.
The TV window can be displayed in large or small sizes. Select either Display Small TV Window or Display Large TV Window from the System menu. Note that you cannot change the size while the TV window is open.
Video On/Off
Normally, you will not need to use the On/Off buttons, since the video is
turned on when the TV dialog is opened, and turned off when it is closed.
Nevertheless, you can click the On button at any time to turn on the video, or one of the Off buttons to shut off the video (and turn off the SED multiplier).
Pont and Area Modes
When you turn the video off, you can either set the beam into point mode or
area mode. In point mode, the beam is fixed in the center of the image. In area
mode, the beam does a fast raster over the same area as the tv.
By default, if you simply close the TV dialog, the beam is set into point
mode, unless you have explicitly turned it off and set it to area mode.
Note: When acquire AugerScan acquisitions in area mode, you should typically set the time/step to at least
200mS per point, to ensure a complete scan during each point.
Scanning Controls
Resolution
There are two resolutions available from the Resolution combo-box: 512x512 and 256x256. While 512x512 obviously produces higher
resolution TV images, 256x256 usually allows you to run at a slightly higher frame
rate
Frame Rate
Select the frame rate from the Rate combo-box. Slowing down the frame rate may result in better (less noisy
images). Note that the highest frame rate (5 frames/sec.) is not always attainable,
however, by reducing the resolution to 256x256, you can approach this speed.
Rotation
Type or scroll a value in the Rotation field to rotate the image. The image is rotated using system control
hardware (as opposed to simply using a software solution), and can be rotated through
360 degrees.
Setup
The following controls assist in setting up your video signal to achieve the
best image quality:
Y Modulate
Checking the Y-Modulate box sets the TV into a special diagnostics mode, which effectively graphs the
video signal range within the TV image. When you click Y-Modulate, you are no longer looking at the TV image, but a virtual “oscilloscope” showing the video signal. Using the image controls (described below), along with the SED multiplier voltage, you can make adjustments and monitor the results using Y-Modulate to see if
the video signal is optimal.
Generally, you want the largest possible signal range without clipping, which
will show up as flat lines along the bottom or top of the signal. You will
need to be imaging over an area with a reasonable amount of contrasting features
to effectively use Y-Modulate. You should see a signal made of “dots” filling at least half the area of the TV monitor. Any clipping will show up
as horizontal lines on the bottom or top of this signal. A number of
parameters will affect clipping, but the SED multiplier voltage and offset (described
below) will often have the greatest affect.
Auto-Focus
Clicking the Auto-Focus button will set the objective control to a value the will produce the best-focused image. This may take a few
seconds. Note that you will probably still need to adjust the fine focus to for
the best image. You should already have a reasonable video signal and
contrasting image before using Auto-Focus.
Copy Screen
Click the Copy Screen button to copy the TV image to the cliboard (as a bitmap). This is very
useful for getting a quick image without resorting to acquiring an SED or ABS image
acquisition. The highest resolution for this image is 512x512
Show Crosshairs
Checking the Show Crosshairs option displays a set of crosshairs on the live TV image. The center of the
crosshairs marks the center of the image.
Image Controls
The following controls affect the video signal and overall video quality.
Note that the signal range is also affected somewhat by the SED multiplier voltage. Also, it may be easier to adjust these values using the Y-Modulate mode
(described above) than using the image alone.
Brightness
Use the Brightness slider to control the overall image brightness from 0 to 100%. Normally, the
brightness will be at least 60% or higher.
Contrast
Use the Contrast slider to control the overall image contrast from 0 to 100%. Normally, the
contrast will be at least 60% or higher.
Gamma
Use the Gamma slider to control the overall image gamma from 0 to 100%. The gamma affects
the linearity of the contrast. The gamma is normally set to 0%, however
setting it higher may help to improve overall contrast.
Offset
Use the offset slider to adjust the offset (the DC, or “black” level) of the image between 0 and 50%. This level will affect the range of
the image signal, which should be as high as possible without clipping (see the Y-Modulate information). Normally, the offset will be between 15% and 25%.