- #1
Urvabara
- 98
- 0
I am just "trying" to watch interstellar TV...
The detection range in lightyears is
R = \sqrt{\frac{\text{EIRP}\cdot A_{e}_{r}\cdot\text{twc}}{4\pi\cdot\text{SNR}\cdot B_{r}\cdot k_{B}\cdot T_{sys}}}\cdot\frac{1\,\text{ly}}{9454254955488000\,\text{m}}, where
\text{EIRP} = P_{t}G_{t},
\text{twc} = \sqrt{B_{r}t} = 1\,\text{for modulated signals,}
\text{SNR} is signal-to-noise ratio,
A_{e}_{r} is receiver's radio telescope's effective area,
B_{r} is receiver's bandwidth which is larger or equal to transmitters bandwidth,
k_{B} is Boltzmann's constant and
T_{sys} is system's temperature in Kelvins.
I put these numbers in:
\text{EIRP} = 15000\,\text{W},
A_{e}_{r} = 15707963\,\text{m}^{2},
\text{twc} = 1,
\text{SNR} = 22,
B_{r} = 8\cdot 10^{6}\,\text{Hz},
k_{b} = 1.3806504\cdot 10^{-23}\,\text{J/K}, and
T_{sys} = 10\,\text{K}.
I get: R = 0.000093\,\text{ly}.
Questions:
1. Is the equation correct?
2. Is my answer about correct?
3. How to reduce the SNR?
4. How to reduce the system temperature?
5. Can I really rise the detection range just only reducing the system temperature? So technically I can watch interstellar TV shows with a very, very small disc, if I can go to very near the absolute zero?
The detection range in lightyears is
R = \sqrt{\frac{\text{EIRP}\cdot A_{e}_{r}\cdot\text{twc}}{4\pi\cdot\text{SNR}\cdot B_{r}\cdot k_{B}\cdot T_{sys}}}\cdot\frac{1\,\text{ly}}{9454254955488000\,\text{m}}, where
\text{EIRP} = P_{t}G_{t},
\text{twc} = \sqrt{B_{r}t} = 1\,\text{for modulated signals,}
\text{SNR} is signal-to-noise ratio,
A_{e}_{r} is receiver's radio telescope's effective area,
B_{r} is receiver's bandwidth which is larger or equal to transmitters bandwidth,
k_{B} is Boltzmann's constant and
T_{sys} is system's temperature in Kelvins.
I put these numbers in:
\text{EIRP} = 15000\,\text{W},
A_{e}_{r} = 15707963\,\text{m}^{2},
\text{twc} = 1,
\text{SNR} = 22,
B_{r} = 8\cdot 10^{6}\,\text{Hz},
k_{b} = 1.3806504\cdot 10^{-23}\,\text{J/K}, and
T_{sys} = 10\,\text{K}.
I get: R = 0.000093\,\text{ly}.
Questions:
1. Is the equation correct?
2. Is my answer about correct?
3. How to reduce the SNR?
4. How to reduce the system temperature?
5. Can I really rise the detection range just only reducing the system temperature? So technically I can watch interstellar TV shows with a very, very small disc, if I can go to very near the absolute zero?
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