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XLjedi · 07-23-07, 08:56 AM

You know the target heading
You know the bearing of the target at T-00
You know the bearing of the target at T-40
You've triangulated the target position at T-40

With that, you can plot the TC (true course) of the target. You can measure the distance the target traveled over its TC and use Distance and Time to determine speed.

Here's your work so far... (it appears correct, TMA solution seems reasonable)

You triangulated the target position, so plot a contact on the triangulated location.

Notice above I added a node and connected Contact to Node so I could make sure I was gettng the TMA heading solution of 305° accurate. I entered time for the contact as 40 and I plotted the node at the T-00 bearing.

Now when I use the TSD feature (hover mouse over contact and press Y key), MoBo shows the time elapsed and solves for target speed.

The TSD solution calculated 6.5 knots as the contact speed.

MoBo knows the distance travelled for any plotted line, let's display it for ourselves...

So between T-00 and T-40 the contact travelled about 8000m.

MoBo was doing the nomograph work for you, but since you've got it there, let's draw the line to determine speed.

Drawing the line on your nomograph for T-40 and 8000m shows 6.5 knots.

Good news is, you can probably continue your advance submerged and catch the contact. ...as long as your speed is at least 5 knots.

07-23-07, 08:56 AM	#2
XLjedi Ace of the Deep Join Date: Jun 2005 Location: Palm Beach, Florida Posts: 1,243 Downloads: 53 Uploads: 8	You know the target heading You know the bearing of the target at T-00 You know the bearing of the target at T-40 You've triangulated the target position at T-40 With that, you can plot the TC (true course) of the target. You can measure the distance the target traveled over its TC and use Distance and Time to determine speed. Here's your work so far... (it appears correct, TMA solution seems reasonable) You triangulated the target position, so plot a contact on the triangulated location. Notice above I added a node and connected Contact to Node so I could make sure I was gettng the TMA heading solution of 305° accurate. I entered time for the contact as 40 and I plotted the node at the T-00 bearing. Now when I use the TSD feature (hover mouse over contact and press Y key), MoBo shows the time elapsed and solves for target speed. The TSD solution calculated 6.5 knots as the contact speed. MoBo knows the distance travelled for any plotted line, let's display it for ourselves... So between T-00 and T-40 the contact travelled about 8000m. MoBo was doing the nomograph work for you, but since you've got it there, let's draw the line to determine speed. Drawing the line on your nomograph for T-40 and 8000m shows 6.5 knots. Good news is, you can probably continue your advance submerged and catch the contact. ...as long as your speed is at least 5 knots. __________________ Last edited by XLjedi; 07-23-07 at 01:06 PM.