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Well one thing that has had me stumped for awhile now is how radar works on a sphere.

[h=3]Cut and pasted from a west marine website about recreational boater radars....

How far do you need to see?[/h][FONT=&quot]This question, how much range you want from a radar, involves a couple of factors and some trade-offs. First, there’s the factor of height. Your radar can’t see over the earth’s curved horizon, so the height of your unit above the ocean surface, and the height of the target you’re looking at limit how far away you can identify objects.[/FONT]
[FONT=&quot]For the techies among us, here is a simple formula: (1.22 nautical miles x square root of height of radar) + (1.22 nautical miles x square root height of target) In simple English, that means that if your boat has an antenna on a T-top that’s nine feet off the water, and you’re searching on the screen for a boat that’s the same size, you’ll need to be within 7.3 nautical miles (1.22 x 3 + 1.22 x 3 = 7.32).

Assuming this is a correct formula from west marine and the statement from west marine that says their radars can't see over the curved horizon is correct and using the curvature of the earth formula of about 8 inches of curve per mile squared, the other boat would have to be 35 ft tall at 7.3 miles in order for the radar to even see it. 35 ft tall is not a boat of similar size with a T top at 9 ft. I'm NOT a math wiz by any means, so what am I missing here?? [/FONT]

<blockquote data-quote="KDM" data-source="post: 250302" data-attributes="member: 314">Well one thing that has had me stumped for awhile now is how radar works on a sphere.&nbsp; [h=3]Cut and pasted from a west marine website about recreational boater radars....How far do you need to see?[/h][FONT=&amp;quot]This question, how much range you want from a radar, involves a couple of factors and some trade-offs. First, there’s the factor of height. Your radar can’t see over the earth’s curved horizon, so the height of your unit above the ocean surface, and the height of the target you’re looking at limit how far away you can identify objects.[/FONT][FONT=&amp;quot]For the techies among us, here is a simple formula: (1.22 nautical miles x square root of height of radar) + (1.22 nautical miles x square root height of target) In simple English, that means that if your boat has an antenna on a T-top that’s nine feet off the water, and you’re searching on the screen for a boat that’s the same size, you’ll need to be within 7.3 nautical miles (1.22 x 3 + 1.22 x 3 = 7.32).Assuming this is a correct formula from west marine and the statement from west marine that says their radars can't see over the curved horizon is correct and using the curvature of the earth formula of about 8 inches of curve per mile squared, the other boat would have to be 35 ft tall at 7.3 miles in order for the radar to even see it.&nbsp; 35 ft tall is not a boat of similar size with a T top at 9 ft.&nbsp; I'm NOT a math wiz by any means, so what am I missing here??&nbsp; [/FONT]</blockquote>

[QUOTE="KDM, post: 250302, member: 314"] Well one thing that has had me stumped for awhile now is how radar works on a sphere. [h=3]Cut and pasted from a west marine website about recreational boater radars.... How far do you need to see?[/h][COLOR=#505050][FONT=&quot]This question, how much range you want from a radar, involves a couple of factors and some trade-offs. First, there’s the factor of height. Your radar can’t see over the earth’s curved horizon, so the height of your unit above the ocean surface, and the height of the target you’re looking at limit how far away you can identify objects.[/FONT][/COLOR] [COLOR=#505050][FONT=&quot]For the techies among us, here is a simple formula: (1.22 nautical miles x square root of height of radar) + (1.22 nautical miles x square root height of target) In simple English, that means that if your boat has an antenna on a T-top that’s nine feet off the water, and you’re searching on the screen for a boat that’s the same size, you’ll need to be within 7.3 nautical miles (1.22 x 3 + 1.22 x 3 = 7.32). Assuming this is a correct formula from west marine and the statement from west marine that says their radars can't see over the curved horizon is correct and using the curvature of the earth formula of about 8 inches of curve per mile squared, the other boat would have to be 35 ft tall at 7.3 miles in order for the radar to even see it. 35 ft tall is not a boat of similar size with a T top at 9 ft. I'm NOT a math wiz by any means, so what am I missing here?? [/FONT][/COLOR] [/QUOTE]

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