Final answer:
Landsat 7's whiskbroom technology employs a mechanical mirror for scanning the Earth, while Landsat 8's pushbroom technology uses a stationary sensor array for image capture. Pushbroom offers better spatial resolution, reduced geometric distortion, and greater radiometric consistency. Additionally, LiDAR is adept at producing precise topographical maps by detecting wavelength variances caused by vegetation and sediment.
Step-by-step explanation:
Differences Between Whiskbroom and Pushbroom Technologies
The OLI detector parameters characterized prior to launch include aspects such as radiometric calibration, spatial resolution, spectral response, and linearity among others. Understanding the technology behind imaging systems is essential to appreciate these parameters. Landsat 7 used whiskbroom technology, which involves a mechanical mirror moving back and forth to scan the Earth's surface line by line. In contrast, Landsat 8 uses pushbroom technology, which has an array of detectors fixed in place that captures an image swath as the satellite orbits.
The main advantages of pushbroom technology over whiskbroom are increased spatial resolution due to less geometrical distortion, improved signal-to-noise ratio, and longer detector lifespan since there are no moving parts. Additionally, pushbroom sensors provide more uniform radiometric performance across the swath.
Using LiDAR for Topography Imaging
LiDAR utilizes wavelength reflections to create precise images of topography. It leverages different wavelengths' sensitivity to variations caused by vegetation and sediment changes, which assists in identifying past geological features such as channels. This can be seen in Figure 9.2, which showcases the detailed topographical mapping capabilities of LiDAR technology.