A remote sensing satellite provides images with a spectral resolution of 10 nm (nanometers). This means
- Athe smallest ground object that can be distinguished is 10 nm across
- Bthe sensor can record energy in very narrow wavelength intervals (10 nm wide)Correct
- Cthe satellite revisits the same area every 10 nm of time (nanodays)
- Dthe radiometric precision is 10 nanowatts per square meter
Solution
Concept
Spectral resolution definition and band width
Formula
Δlambda = λmax - λmin = 10 nm
Step-by-step solution
1. Spectral resolution describes the number and width of spectral bands captured by an optical sensor. 2. A value expressed in nanometers (10 nm) represents the spectral band interval or bandwidth (Delta λ). 3. Narrow band channels (e.g. 10 nm) allow discriminating subtle diagnostic absorption features in vegetation and minerals. Answer: B
Explanation
Spectral resolution refers to the ability of a remote sensing sensor to resolve fine wavelength intervals across the electromagnetic spectrum. A spectral resolution of 10 nm indicates that the sensor records radiation within discrete, narrow bands that are each 10 nanometers wide, characteristic of hyperspectral sensors. Therefore, option B is correct.
Why the other options are wrong
A) The smallest ground object size defines spatial resolution (ground sampling distance), not spectral. C) Revisit intervals define temporal resolution (days/hours). D) Radiometric resolution describes sensor sensitivity to brightness quantization (bits), not spectral intervals.
Shortcut
Spectral = Wavelength band width (nm); Spatial = Ground pixel size (m).
Common mistake
Confusing spectral resolution (measured in nm of wavelength) with spatial resolution (ground size in meters) or temporal resolution.
Correct answer: B) the sensor can record energy in very narrow wavelength intervals (10 nm wide)