Cross Correlation and Semblance Test Graphs

The following table contains the results of auto, cross coorelation and semblance tests on our sample cases.

The first column is the auto-coorelation of the (short) event itself. The auto-coorelation is documented here. Look for significant positive values in the tale, an indicator of wave like behavior.

The second column is the data that contains the event.

The third column is the cross-correlation of the event with the various satellites' data. Cross coorelation is defined here. Look for a high (>.35) well defined peak, indicating a well coordinated event. I coordinated event 3 with satellites 2, 3, 4, and 5. You should expect the height of the 3,3 event to be an indicator of the quality of the event, and the relative maximums of each of the other heights are an indicator arrival of the event at the other satellites.

The fourth column is the semblance of the event with the various satellite's data. Semblance is defined here. Look for a high (>.70) well defined peak, indicating a well coordinated event. I coordinated event 3 with satellites 2, 3, 4, and 5. You should expect the height of the 3,3 event to be an indicator of the quality of the event, and the relative maximums of each of the other heights are an indicator arrival of the event at the other satellites. While cross correlations are between -1 and 1, semblances are between 0 and 1. 0 means the event and data are negatives of each other, .5 means they are unrelated, and 1 means they are identical to each other.

The actual arrival times in tabular form are documented here.

Click on an image to get the full sized version.
NameAutoCorDataXCorSemblanceData ZoomXCor Zoom
.mag_3_5_1506_bad
mag_3_5_1513
mag_3_5_1516
mag_3_5_1521_bad
scp_1_14_1042
scp_1_14_1237_bad
scp_1_14_1249
scp_3_5_1513
scp_3_5_1515_bad
scp_3_5_1516
scp_3_5_1517
scp_3_5_1522_bad
scp_3_5_1526
scp_3_5_long
scp_7_15_01
scp_7_15_01_spinavg

Wm P. Kamp