The multiplicity trigger fires when a specified number of tubes are each above a specified signal. The pattern trigger fires when these specified number of tubes are adjoining. Theoretically, a pattern trigger must also be a multiplicity trigger. For the new 490 pixel camera, all real images recorded are required to pass a three-fold pattern trigger. The cuts for the new 490 pixel camera are shown in the following table.
Degrees are as projected onto the sky.
Image Parameterisation Frac2 is the fraction of the total light in the top two tubes. The cut above thus excludes any images that consist of only two tubes. Size is the sum of light in the image. Max1 and Max2 are the values of the highest and second highest tubes, respectively. The cut on this above eliminates very small images.