User Guide

STADIMETER STATION
Using a photo of a contact taken through the Periscope,the Stadimeter allows you to classify the
contact as well as determine its range and course.
NOTE: The Stadimeter can only be accessed from the Periscope Station.
• Press to reach the Periscope Station, then press the Stadimeter button.
When the Stadimeter appears, the last photo you took through the periscope appears in a window.
Your ship’s computer scans its database of silhouettes and creates a list of those classes that have
a length close to that of the ship in the photograph.The ships that fit this criterion can be selected
one at a time and their silhouettes viewed and rotated in the Silhouette Window.
Manipulating the photo allows you to determine the contact’s range. Finding a 3D silhouette that
matches the photo allows you to classify the contact. Rotating the 3D silhouette to closely match
the aspect seen in the photo helps you determine the AOB.When you know the bearing to the
contact and the AOB, you can fairly accurately determine its course.
DETERMINING COURSE WITH STADIMETER
When you know the bearing to the contact and the AOB,you can obtain a fairly accurate
determination of its course by doing some simple arithmetic.The Seawolf does the math for you
and simply presents you with the contact’s course. In both the 688(I) and the Akula you must do
the arithmetic for yourself.
Assume you have a contact bearing 235 and you have determined the class of the ship and
located the ship’s silhouette in the Stadimeter. Once you have rotated the 3D silhouette until the
view of the model matches the aspect seen in the photo, you know the AOB for the contact. (This
number appears in the AOB field.) Assume that the AOB of the contact is port 42. This is all the
information you need to determine the contact’s course.
1. Find the reciprocal of the bearing to the contact.This is the contact’s bearing to you. In our
example the reciprocal of 235 is 55. Follow these steps to determine the reciprocal.
• If the bearing to the contact is 0 – 180
add 180 to the bearing number.
• If the bearing to the contact is 180 – 360
subtract 180 from the bearing number.
2. Once you have determined the reciprocal of the bearing to the contact, add or subtract the
number in the AOB window as shown below.
• If the contact has a
port aspect, add the number in the AOB window to the reciprocal.
• If the contact has a
starboard aspect, subtract the number in the AOB window from the
reciprocal.
3. If the resulting number is greater than zero and less than 360, this is the course of the contact.
In our example the reciprocal is 55 and the AOB is 45.The contact’s course is 100.
• If the number is
greater that 360, subtract 360.The resulting number is the contact’s course.
• If the number is
less than zero, add 360 to it.The resulting number is the contact’s course.
Because the interfaces for Stadimeter are quite different, instructions for using this feature on each
controllable sub are covered separately below.
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