Question 1

For a blackbody, the frequency at which maximum energy is emitted is 3 x 10¹³ Hz:

A. Give a wavenumber for the wavelength of the infrared emission?

B. What is the temperature of the blackbody?

C. What is the total radiance emittance for the blackbody?

D. Consider an emitter (with an emissivity of 0.5) at the same temperature of the blackbody (obtained from B). What is the total power lost by this emitter if its area is 2 m² ?

Question 2 (Infra-Red Detectors & Optic Lens)

Part A) Infra-Red (IR) Detectors:

An IR detector has an impedance of Z= (400+j200) ? .

During design tests the detector current is measured as 4 µA.

What is the output voltage of the detector?

Part B) Optic lens:

Using a converging lens of focal length f= 10 cm, we want an object to appear on the screen twice as big as its original size.

Where is the object to be located in front of the screen (real image)?

Question 3 (Digital Image)

Part A)

What is the raw file size for an image of 80 rows and 100 columns, with pixels on 14 bits and with an extra row for the header?

Part B)

The minimum and maximum values observed in a low-contrast 12-bit thermogram are 60 and 250, respectively. A pixel in the thermogram has been mapped into a new value of 4000 after linear stretching. What was the value of the pixel before stretching?

Part C)

Regarding filtering, image masking & convolution. Assume we have the following Infra-Red image:

What filter would you use to remove the impulsive noise in the first row of the image (assume 1 x 3 filter)?

What would the first row of the image be after filtering (assume 1 x 3 filter)?