Read This First

There is a row in the table for each sonic at each site. The first column is the site, the second is the nominal height of the sonic, and the third is the type of sonic. The first three columns, the ones in bold, should not change.

If a sonic is not actually at the nominal height, you can edit the actual height field for that sonic, but initially all the actual heights are filled in with the nominal height.

To record the horizontal orientation of a sonic, measure the bearing of the boom relative to magnetic north looking along the boom towards the tower. In the measurement columns on the right, record the measured bearing, who made it, and any other relevant notes, like how it was made. For example, 99 deg, gg, handheld compass, 12/15/2016. If there is more than one measurement for a sonic, then more than one measurement column will be filled in. Finally, derive the best approximation for the boom angle from all the measurements and enter it in the Bearing column. Derive the angle as an average, or just pick the most reliable measurement.

Usually all the sonic booms on a tower have the same bearing, in which case you can copy one measurement to all the heights at that site.

The sonic type should be enough to indicate how the sonic is mounted relative to the boom, as indicated in the table below. If a sonic is not mounted according to the conventions below, then the boom angle bearing in the table needs to be adjusted accordingly. For example, if a sonic is rotated 180 degrees from the conventional orientation, then add 180 degrees to the boom angle and note that in one of the the measurement columns.

This table is scraped by a script to extract all the angles and generate calibration files for NIDAS processing, so the layout should not change and the meaning of the columns should not change. Other than that, edit it like you would any other wiki page.

Sonic Angles Table

The boom angle is the bearing of the boom pointing away from the tower relative to magnetic north, in units of degrees. If you shoot the angle looking along the boom towards the tower (ie, so the tower is not obstructing the view of the boom), then add 180 degrees to get the boom angle expected in this table. Initially we just need rough estimates in this table.