Target angle submarine observer estimating target angle pictures himself on the target ship looking back at the submarine. Relative bearing of the submarine is the clockwise angle in degrees from the heading of the target ship to a straight line drawn from the target ship to the submarine. When target angle is 0° (or 360° ) the target ship is coming directly toward the submarine. Target angles between 0° and 90° indicate the target ship is moving toward and to the right of the submarine. Target angles between 90° and 180° indicate the target ship is moving to the right and away
Type 97 90 mm Infantry Mortar Light Trench Mortar, Manufactured in 1942, Osaka Army Arsenal". The Type 97 is approximately lighter than the Type 94 90-mm mortar. This weight saving was created largely by the elimination of the Type 94's recoil mechanism, which weighed . The bipod assembly of the Type 97 is lighter than that on the Type 94. There is a cover for the level on the yoke of the Type 97 which is not on the Type 94, and the sliding bracket of the Type 97 is hinged to permit its easy removal from the leg of the bipod, whereas it is integral