Question

Remote Sensing:

• Basic Definitions: radiance, reflectance, wavelength regimes (vis, IR, MW), Lookup tables, forward versus Inverse, active versus passive.

-Question: A 1 cm2 detector absorbs 28 Joules of light in 4 seconds. If the detector is at the bottom of a cylinder with a radius of 2 cm and 18 cm deep, what radiance would you calculate from this information?

-Question: Light is measured to have a frequency of 4 x 1013 Hz. What type of light would you classify this as? (vis, IR, MW, radio)

-Question: When the weather service ingests satellite data into the weather models, it does it differently than you might expect. For example, instead of matching the model produced cloud optical depth and droplet sizes to satellite retrievals of cloud optical depth and droplet sizes, it uses the model produced clouds to predict the amount of light they would reflect, and compares that to the satellite observed reflected light. Explain why this is considered the better way to do a comparison.

Answer 1

sol r = 2cm Radiance L Irradiance (E) solid angle Irradiance (EJ = Ih=18 deep. optical power hitting Detector Area. Optical power the arriving at detector. Pd As Lg As Ad solid angle. 28 Pa 7 watts olet 2 Ls P ។ d² Ad (18) 16m2 As W 180.57 Ls 4 180.57 x 10 لا ema SY m²-si Radiance į ISO:57 브 180.57x104 w m²_sr cm²_sr 2 f = 4x10 8 Hz . C - 3 *lo mi' X = ult Bx103 3x108 4 4 x m 1. 33 x lo 13.3 Xlom 13.3um Light should be Infra Red (IR). Sizes aure in cases of Cloud droplet with Clould optical depth. But positive Corrrelations found over with moderate Resolution Imaging it is better way to Compare the are negatively correlated study, Certain portions of world, Spectoradiometer. So, we weather models and satellite data,