Re-design transmitter radius analysis in code to give each orbit its optimum transmitter radius

[MatthewGrim]

As #45 showed, the optimum transmitter radius varies from orbit to orbit. At the moment, it has not been shown that our optimisation technique finds the global minimum because it does not find the optimum transmitter size for every orbit at the same time. This has been shown in #44 to not be difficult to do, so we can add it to the code for robustness, and to be sure that we are achieving the optimal solution.

This issue documents this re-factor of the optimisation routine.

[MatthewGrim]

In this issue, I have talked about the re-design of the satellite transmitter optimisation. This involves the following steps:

• Change the optimize_link_efficiency to choose a transmitter radius optimised for the maximum range of the satellite from the target.
• If the transmitter radius at this point is too small to meet the pointing requirement, increase the beam size until it is just able to.

This produces a set of designs at every altitude that should be able to pass the pointing requirement, and the optimum beam aperture for every orbit. It does not solve the problem for if the transmitted beam can fit inside the target.

[MatthewGrim]

For comparison - these should not change or improve: AMALIA Iteration: 0, Max radius: 1.12 ------------------------------- SATELLITE ORBIT ------------------------------- Number of SPS: 1 Optimal orbit altitudes --> Perigee: 1200.0 km, Apogee: 1400.0 km Orbital period --> 250.28 minutes Total active time (blackout reduction) --> 6.04 % Total blackout time --> 43.72 % Max active period duration --> 0.94 hours Max blackout period duration --> 13.31 hours Min range to target --> 2183.26 km Max range to target --> 2531.95 km ------------------------------ LASER TRANSMITTER ------------------------------ Minimum allowable transmitter power --> 3.44 kW Transmitter aperture radius: 88.44 cm Mean link efficiency --> 7.44277 % Mean power delivered --> 110.78 W Steady state temperature --> 70.17 Celsius --------------------------- BATTERY CHARACTERISTICS --------------------------- Battery capacity --> 11590.17 Whr Battery mass --> 82.79 kg Battery cycles --> 21000.4 Battery charge time --> 2.09 hr --------------------------- RECEIVER CHARACTERISTICS --------------------------- Receiver Area --> 0.365764447695684 $m^2$ Mean flux at receiver --> 0.44 AM0 Maximum flux at receiver --> 0.47 AM0 Minimum flux at receiver --> 0.4 AM0 Mean heat load on receiver --> 110.78 W Total energy transferred --> 7099.24 MJ per year

Sorato Iteration: 0, Max radius: 1.12 ------------------------------- SATELLITE ORBIT ------------------------------- Number of SPS: 1 Optimal orbit altitudes --> Perigee: 2300.0 km, Apogee: 2300.0 km Orbital period --> 383.57 minutes Total active time (blackout reduction) --> 10.42 % Total blackout time --> 39.34 % Max active period duration --> 1.91 hours Max blackout period duration --> 5.5 hours Min range to target --> 3065.15 km Max range to target --> 3644.01 km ------------------------------ LASER TRANSMITTER ------------------------------ Minimum allowable transmitter power --> 4.96 kW Transmitter aperture radius: 105.62 cm Mean link efficiency --> 1.12192 % Mean power delivered --> 24.06 W Steady state temperature --> 67.63 Celsius --------------------------- BATTERY CHARACTERISTICS --------------------------- Battery capacity --> 26875.83 Whr Battery mass --> 191.97 kg Battery cycles --> 13702.72 Battery charge time --> 3.2 hr --------------------------- RECEIVER CHARACTERISTICS --------------------------- Receiver Area --> 0.07863935625457205 $m^2$ Mean flux at receiver --> 0.45 AM0 Maximum flux at receiver --> 0.48 AM0 Minimum flux at receiver --> 0.4 AM0 Mean heat load on receiver --> 24.06 W Total energy transferred --> 1845.36 MJ per year

[MatthewGrim]

Current results: AMALIA ------------------------------- SATELLITE ORBIT ------------------------------- Number of SPS: 1 Optimal orbit altitudes --> Perigee: 1300.0 km, Apogee: 1300.0 km Orbital period --> 250.28 minutes Total active time (blackout reduction) --> 6.12 % Total blackout time --> 43.64 % Max active period duration --> 0.87 hours Max blackout period duration --> 4.99 hours Min range to target --> 2186.05 km Max range to target --> 2490.95 km ------------------------------ LASER TRANSMITTER ------------------------------ Minimum allowable transmitter power --> 3.37 kW Transmitter aperture radius: 92.11 cm Min link efficiency --> 6.86157 % Min power delivered --> 100.0 W Mean link efficiency --> 7.41458 % Mean power delivered --> 108.06 W Steady state temperature --> 67.63 Celsius --------------------------- BATTERY CHARACTERISTICS --------------------------- Battery capacity --> 8237.55 Whr Battery mass --> 58.84 kg Battery cycles --> 21000.4 Battery charge time --> 2.09 hr --------------------------- RECEIVER CHARACTERISTICS --------------------------- Receiver Area --> 0.365764447695684 $m^2$ Mean flux at receiver --> 0.43 AM0 Maximum flux at receiver --> 0.45 AM0 Minimum flux at receiver --> 0.4 AM0 Mean heat load on receiver --> 108.06 W Total energy transferred --> 7164.36 MJ per year

Sorato ------------------------------- SATELLITE ORBIT ------------------------------- Number of SPS: 1 Optimal orbit altitudes --> Perigee: 2300.0 km, Apogee: 2300.0 km Orbital period --> 383.57 minutes Total active time (blackout reduction) --> 10.42 % Total blackout time --> 39.34 % Max active period duration --> 1.91 hours Max blackout period duration --> 5.5 hours Min range to target --> 3065.15 km Max range to target --> 3644.01 km ------------------------------ LASER TRANSMITTER ------------------------------ Minimum allowable transmitter power --> 4.93 kW Transmitter aperture radius: 111.41 cm Min link efficiency --> 1.00843 % Min power delivered --> 21.5 W Mean link efficiency --> 1.11557 % Mean power delivered --> 23.78 W Steady state temperature --> 67.63 Celsius --------------------------- BATTERY CHARACTERISTICS --------------------------- Battery capacity --> 26723.73 Whr Battery mass --> 190.88 kg Battery cycles --> 13702.72 Battery charge time --> 3.2 hr --------------------------- RECEIVER CHARACTERISTICS --------------------------- Receiver Area --> 0.07863935625457205 $m^2$ Mean flux at receiver --> 0.44 AM0 Maximum flux at receiver --> 0.47 AM0 Minimum flux at receiver --> 0.4 AM0 Mean heat load on receiver --> 23.78 W Total energy transferred --> 1834.91 MJ per year

[MatthewGrim]

These receivers, eye balling it, are in the same orbits-ish, and have slightly better efficiencies. This is a good sign that the code has worked, but I should probably do a double check tomorrow with meld when I am more awake. I will commit this change in any case - it can always be reverted.

[MatthewGrim]

This new implementation is not the default implementation.