All submarines have several methods by which they can determine a general navigational position or a precise navigational fix:
1. GPS Satellite Network or SatNav fix
2. Electronic Gyroscope
3. Dead Reckoning plot
4. Radio Bearing
5. Visual Aid (close to shore, e.g., lighthouse, landmark, etc.)
6. Sunline (Sextant can be used when surfaced, or attached to Periscope while submerged)
7. Radar
For target range calculation, it depends on whether or not it's a visual and Sonar target, just visual, or just on Sonar. Visually, range markers on the Periscope indicate estimated range, however unless circumstances warrant, that range will always be verified and compared with Sonar range.
Sonar ranges are determined over time by tracking the target through induced turns (zigs), either by the submarine or the target. Either way, the change in direction adds another leg to the target tracking solution; eventually an estimated range based on known, sound trigonometric calculations weil be formulated, either by computer (normal) or by hand (backup). The tracking solution takes into account several known variables given by Sonar:
1. Estimated target speed (RPM) and type (e.g., Merchant, Warship, Trawler, etc.)
2. Sonar bearing
3. Closing or Opening Range (target getting closer or moving away)
Sonar's given target tracking information is based on the current sound profile for the given operating area the submarine is in, as all information is based on the current speed of sound in water, which can change.
In the end, target speed, bearing, and course are the key factors in determining range prior to a torpedo shot; however, in most circumstances, the shooting submarine will check a target's range with all other information plotted with active Sonar echo ranging (usually only 1 or 2 pings to verify range). If the range matches the plot, the information is fed into the torpedo guidance computer prior to shooting.
Submarines have several ways of determining position by navigation: 1. Satellite - GPS - All Submarines have GPS receivers aboard that can help pinpoint their position to within feet on the planet. 2. Electronic Inertial Navigation - Electronic Gyroscope systems maintain a continous plot of where the boat is. 3. Chart Position/Dead Reckoning - the Dead Reckoning plot keeps position under a navigational chart of the area. While not a perfect position, it's better than nothing if everything else isn't working. 4. Radar - Only when used within range of land. 5. Visual - Used primarily when entering port, via sight of landmarks, buoys, etc., matched against a chart of the area. All submarines use active and passive Sonar to determine target range, though active is more reliable. Passive Sonar requires ship directional course changes and plotting to determine range. Active Sonar works both ways though; use it and you give away your position.
use a piggy bank and measure the distance from the piggy bank and a star
Measure from the skimmer box to the furthermost point away and add 2mt
How close and far something is from you.
away from,toward
away from; toward
Because
The general tendency is for galaxies that are farther away from us, to move away from us faster. This can give a rough idea of a galaxy's distance, just by observing its redshift (which is a measure of how fast it moves away from us).
The main method is through listening using passive Sonar. Active sonar sends out a sound signal that can be used to bounce off the enemy. It may also give away their own position.
No, 'years' is a measure of time and 'light years' is a measure of distance.
It is said that math is used everyday. Knowledge of mathematics is needed in seafaring to determine how far someone has gone, how far away something is, and how fast the boat is going and in what direction.
Sound waves travel very well in water. Warships, including submarines, use passive sonar to listen for enemy ships and submarines. Passive sonar employes underwater hydrophones to listen for sounds. They can detect sounds of ships and submarines miles away. Marine mamals such as whales and dolphins detect sound in much the same way.