zma
11-28-2005, 08:45 AM
I've made a couple of graphs that depict how deep the SQR-19 towed array will sink as a function of cable scope. The graphs are based purely on observations of array depth at different speeds and cable scopes. You might find the graphs useful if, for example, you are operating in shallow waters and don't want the array dragging the sea floor, or if you have determined the optimal array depth from the SSP, and need to change the cable scope in order to adjust for a change in speed.
The graphs contain curves for five different speeds, ranging from 4 knots to 20 knots. Why not higher speeds? Well, even at 20 knots, there is increased flow noise which reduces the efficiency of the array. Therefore the array depth at higher speeds is, in my opinion, irrelevant information, as the array itself becomes quite useless.
Attached is the graph for the LWAMI mod v2.03
I've decided to wait for the official v103 patch before posting the graph for the "standard" (ie. unmodded) DW. All I have right now is an unverified graph for DW v101, and as verifying it would take a surprising amount of time, I want to play it safe and see if v103 brings any changes with regard to TA depth. Stay tuned.
A word or two about how I've collected the data: First, changing speed or cable scope does not (naturally) show immediately in the array depth. Although it doesn't take longer than a few minutes for the array to get near the new depth, it can take 15 minutes or more before the array has completely settled. Because of this, I always waited at least 15 minutes (sometimes much more!) after changing either cable scope or speed before I observed the array depth.
Second, I've noticed that using time compression can have an effect on the array depth. So, I couldn't use TC at all when collecting the data. With at least 15 minutes between observations, it takes a lot of time to gather all the data. Of course, I'm free to do other stuff between the observations, but still.
Naturally, the sea state and currents can also affect the array depth. For making the graphs, I made a custom mission with sea state 2, no currents and no wind. In heavy seas, you might not see the array depth settle to any steady-state value, but rather oscillate in some range.
OK, I think that's all for now. If you have any questions or feedback about the graph, please post here (or send me a PM/e-mail). Do you think there's something wrong? How could I improve the graphs? Any feedback will be appreciated!
The graphs contain curves for five different speeds, ranging from 4 knots to 20 knots. Why not higher speeds? Well, even at 20 knots, there is increased flow noise which reduces the efficiency of the array. Therefore the array depth at higher speeds is, in my opinion, irrelevant information, as the array itself becomes quite useless.
Attached is the graph for the LWAMI mod v2.03
I've decided to wait for the official v103 patch before posting the graph for the "standard" (ie. unmodded) DW. All I have right now is an unverified graph for DW v101, and as verifying it would take a surprising amount of time, I want to play it safe and see if v103 brings any changes with regard to TA depth. Stay tuned.
A word or two about how I've collected the data: First, changing speed or cable scope does not (naturally) show immediately in the array depth. Although it doesn't take longer than a few minutes for the array to get near the new depth, it can take 15 minutes or more before the array has completely settled. Because of this, I always waited at least 15 minutes (sometimes much more!) after changing either cable scope or speed before I observed the array depth.
Second, I've noticed that using time compression can have an effect on the array depth. So, I couldn't use TC at all when collecting the data. With at least 15 minutes between observations, it takes a lot of time to gather all the data. Of course, I'm free to do other stuff between the observations, but still.
Naturally, the sea state and currents can also affect the array depth. For making the graphs, I made a custom mission with sea state 2, no currents and no wind. In heavy seas, you might not see the array depth settle to any steady-state value, but rather oscillate in some range.
OK, I think that's all for now. If you have any questions or feedback about the graph, please post here (or send me a PM/e-mail). Do you think there's something wrong? How could I improve the graphs? Any feedback will be appreciated!