INTRODUCTION TO REMOTE SENSING EXAM I Name: ID: Question 1‐10 (5% each; no partial credits). THIS EXAM SHEET IS DOUBLE‐SIDED. 1. We can study ocean in the following spectral regions (a) 400‐500 nm (b) 500‐600 nm (c) 1500‐1800 nm (d) 1100‐1200 nm (e) None of the above 2. The following sensors have NO thermal bands (a) ETM+ (b) ASTER (c) IKONOS (d) TM (e) None of the above 3. To increase energy integration time, the pushbroom design is a better choice than a whiskbroom sensor (a) True (b) False 4. Both Terra and Aqua MODIS collect data before noon. (a) True (b) False 5. What sensor(s) have more than one viewing angles? (a) MISR (b) ASTER (c) TM (d) ETM+ (e) none of the above 6. According to the Planck’s Radiation Law, the exited energy for sun peaks at (a) 0.4‐0.5 m (b) Thermal region (c) Visible region (d) Near infrared region (e) Middle infrared region 7. What part of spectral regions are windows for terrestrial research? (a) 1400 nm (b) 0.8‐
0.9 m (c) 1000‐1100 nm (d) 1900 nm (e) 2.2‐2.4 m 8. Which of the following sensor(s) are passive one(s)? (a) GLAS (b) LiDAR (c) ASTER (d) ETM+ (e) MISR 9. In order to effectively collect data in dense forests, an on‐boarded optical sensor can do some adjustment such as (a) increase gain (b) increase integration time (c) change flight altitude (d) collect data at noon (e) enlarge band width 10. Which curve indicates complete decomposition of soil organic matter . 11. A new shortwave albedo 1‐band sensor (NOTE: For the computation question, I don’t want to see just the answer. I need to know how you derive the answer!) National Taiwan University has a new one‐band shortwave albedo sensor named SWA to collect reflected energy within visible and near infrared (VNIR) spectral region. The energy measured by the sensor is about 40% of the total solar energy. It is on the polar orbit. It is an 8‐bit sensor. The gain and offset of the SWA are 8 DN/(W/m2 sr m) and 150 DN, respectively. SWA is collecting data this morning (assuming there is no cloud). The meteorological conditions follow: Sun elevation angle = 60, sensor zenith angle = 30 Optical depth at nadir: molec = 0.3, aersol = 0.2, absorption = 0.3 Earth‐sun distance = 1.1 AU 11‐1. What are the airmasses to the sun and SWA? (10%) 11‐2. What is the surface spectral irradiance at nadir? (10%) 11‐3. Let’s focus on an asphalt surface (lambertian surface is assumed). If the shortwave albedo is 0.35, what is the surface spectral exitance? (10%) 11‐4. What is the at‐sensor spectral radiance and DN value? (10%) 11‐5. What is the at‐sensor spectral radiance and DN value if the surface shortwave albedo is 0.8? (10%)