[TML] Noncanonical TU 3D.

[Jerry W Barrington]

On 1/4/08 2:34 PM, "Anthony Jackson" <ajackson at iii.com> wrote:

> rpg wrote:
> 
>> Active sensors simply matters considrably with a search like this, radar or
>> even just a searchlight would be enough. Much easier than just relying on
>> passive sensors with ambient light.
> 
> Nowhere near as much as you think. Active sensors have some advantages
> for noise reduction, but let's assume a 1,000 meter radar dish, with an
> MDS of 10^-19 joules. Now, the area of the radar is 2.5e5*pi m^2, and
> the area of a 1 AU sphere is 9e22*pi m^2 (3.6e17x greater), so the
> object must be reflecting at 1e-19*3.6e17 joules or 0.036 joules.
> 
> Now, the 1 km object has an area of 2.5e5*pi m^2 (again, 1/3.6e17 times
> the area of the sphere), so to cover the entire sky at 0.036 joules per
> 1 km object, we have to emit 3.6e-2 * 3.6e17 or 1.3e16 joules.
> 
> Assuming a 1 gigawatt radar, that will take about five months.

That's not so bad.  And it might be better to search in other wavelengths,
something that really stands out against the background.  Plus, you could
mount more than 1 radar unit.  5 or more gets you down under a month.