1 / 5

Callisto calibration

Callisto calibration. This equation above describes the function of the logarithmic detector. To solve this equation, we need in principle 3 independent measurements. Callisto calibration. Noise source +35dB enr. FIT. Calibration IDL, C++. Noise source +25dB enr. Callisto spectrometer.

robin-hooper
Download Presentation

Callisto calibration

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Callisto calibration This equation above describes the function of the logarithmic detector. To solve this equation, we need in principle 3 independent measurements

  2. Callisto calibration Noise source +35dB enr FIT Calibration IDL, C++ Noise source +25dB enr Callisto spectrometer 50Ω termination = ~300K

  3. Callisto calibration Known: Vcold, Vwarm, Vhot, Tcold, Twarm and Thot Unknown: Vo, b and Trx This set of non-linear equations can not be solved mathematically correct, it can only be solved numerically But since Trx ~ Tcold << Twarm < Thot, the set of equations can be simplified. This simplification leads to a set which can be solved straight forward.

  4. Callisto calibration

  5. Callisto calibration Final equation for calibration: • Still without taking into consideration second order effects like: • Side lobes • Spill over • Cable loss (antenna – switch) • Noise temperature enhancement by physical temperature of cables (antenna – switch) • To improve, do the same on the cold sky and take the difference S = S(sun) – S(sky) k = Boltzmann constant K = 1 Kelvin λ = wavelength = c/f [m] G = antenna gain Trx = receiver noise temperature [K] V = voltage at one frequency on the sky Vo = offset voltage at the same frequency b = detector coefficient at the same frequency S = radio flux of sky/sun at the same frequency [sfu]

More Related