代写GGR 315 Environmental Remote Sensing, 2024 Assignment 3: Geometric Corrections and Image Enhanceme

GGR 315 Environmental Remote Sensing, 2024

Assignment 3: Geometric Corrections and Image Enhancement

Questions

(100 marks, 10% of the final grade)

1. (20 marks) True/false (circle the right answer).

T  F  1. The longer the wavelength, the higher the frequency.

T  F  2. Landsat TM sensor can detect cars in highways.

T  F  3. The sum of reflectance, absorptance, and transmittance is larger than one.

T  F  4. Data from Landsat TM band 6 in thermal infrared can be used in deriving the surface temperature.

T  F  5. The reflectance of clouds and snow is different in mid-infrared region.

T  F  6. Aerosols in the atmosphere decreases the quality of an image.

T  F  7. Multispectral sensors usually have several broad spectral bands.

T  F  8. The earth’speak emitted wavelength is shorter than that of the sun.

T  F  9. In satellite remote sensing, image data are usually stored in a text (ASCII) file

because this format takes less computer disk space than a binary file. T  F  10. A radar is a passive sensor.

2. (30 mark) Register the image Geo_not_ref_Toronto.tiff,  which is composed of 7 bands of a TM image. Use the geo-coded satellite image provided by ArcGIS Pro as the source  of ground control points (GCP) as the base map. You may use the vector layer to assist the GCP selection. Use 3rd  polynomial as the mathematical model. Brief the process of collecting GCP and print out your GCP list.

3. (10 mark) Find out the geographic coordinates for the following pixels (columns and   rows) (273, 167), (276, 623), (1024, 475), and (1380, 296) in both the original image and the registered image.

4. (20 mark) Give a brief description of nearest-neighbor, bi-linear interpolation, and cubic convolution resampling methods, and explain the advantages and disadvantages of each of these methods for applications with the following considerations: (1) to preserve the numerical integrity of the original image, (2) to minimize the distortion of linear features, (3) to produce smoother images, and (4) to use less computation time.

5. (20 marks) Resampling is one of procedures in geometric corrections. In the following drawing, the open circles (o) are the pixel centers in the original image, and closed circles (•) represent the pixel centers in a new image to be created after resampling. The digital   number of each pixel in the original image is given by the side of each open circle.

1) Write on the side of all closed circles the values after the nearest neighbor resampling. Note that the locations of all circles should be assumed to be exactly at the closest cross  points of the grid.

2) Describe why geometric corrections are needed priori main data analysis.