Green Satin used a series of such measurements to determine both ground speed and drift angle, which were carried out simultaneously by a single cross-shaped antenna with four feeds.
12.
Using the drift angle measured from the auxiliary drift bar, the compass was rotated to that drift angle, and the cursor moved so it lay above the center of the triangle.
13.
Using the drift angle measured from the auxiliary drift bar, the compass was rotated to that drift angle, and the cursor moved so it lay above the center of the triangle.
14.
The angles were then entered manually into the sight; the drive cables were clutched out, the aiming angle entered using the operating handle, and the drift angle set by a small locking screw.
15.
Calculating the proper drift angle is a simple task of basic vector addition, and is commonly carried out on a circular slide rule like the E6B . This is a somewhat time consuming process.
16.
On each leg, the bomb aimer used the reticle to measure the drift angle, either by rotating the wind direction dial on the computor to get the sight head to the right angle, or by unlocking the azimuth control from the computor and turning the sight manually.
