Final Exam for METR155/METR280

Final Exam for METR155/METR280 Dec. 12, 2012 Prof. Jin

4 points each 1. In MODIS aerosol retrieval, how MODIS people correct clouds, air molecule, and surface effects?

2. Advantages of microwave remote sensing Dis-advantage of microwave remote sensing 3. MODIS uses band 1 to observe land surface and measure ______(high, low) reflectance over vegetation area and ______( high, low) over bare soil area.

4. Lidar stands for ______Radar stands for______

5. Wavelength range used in Lidar is______Wavelength range used in Radar is ______

6. C-band is 7.5 micrometer. Its corresponding frequency is ______7. Which is the following law used to retrieve raindrop size a. radar equation b. split window algorithm c. radar resolution d. Planck’s function 8. In MODIS, the AOD of 0.68 and 0.47 wavelength are approximated by: t.68 ~ (r.68 - .50*r2.1)

t.47 ~ (r.47 - .25*r2.1)

a. what are t.68 and r.68

b. Why need to subtract r2.1

c. the coefficients are 0.50 and 0.25 in calculating t.68 and t.47, what does it mean for having different coefficient? 9. What cloud properties are retrieved from MODIS?

10. MODIS is a scanner wit h spectral bands on four focal plane assemblies that image the earth in a swath cross-track and along- track for each sweep of the scan mirror

11. What is CO2-slicing band? What cloud variable is retrieved using this band? What is its limit in terms of cloud retrieving? 12. Why does Ackman’s cloud mask algorithm help cloud fraction algorithm?

13. List slant range, depression angle, incident angle, swath width, near range, far range in the following image

15.What is the use of the bispectral solar reflectance method?

16.Why aerosol is not critical when using satellite to retrieve clouds properties? 17. For an SLAR with the following characteristics:

λ = 1 cm, L = 3 m, H = 6000 m, θ = 60° (θ is the incidence angle), and tp = 100 ns (tp is the pulse length),

What are its range resolution (Rr) and azimuth resolution (Ra), respectively? If the same SLAR is on a satellite platform in a height (H) of 600 km, what will be its azimuth resolution (Ra)? If the incidence angle θ does not change, will the range resolution (Rr) change (assume the ground is flat such that the depression angle  = 90° - θ)?