Mandi Assignment Final Answer

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VAST Challenge 2017 MC 3

Introduction

Data Preparation

Analysis Procedure

Final Answer


Questions:

1. The scale and orientation of the supplied satellite images.
Identified the location and coordinates of the Boonsong Lake in the satellite image as below:
The orientation of the satellite image is the same with that of the Boonsong Lake.
Lake.JPG Axis Image.jpg
Hence, the length of a pixel is 3000/(504 - 475+1) ft, equals to 100 ft. Then the area of one pixel is 100 * 100 = 10000 square ft.
As the satellite image has 651*651 pixels, the actual scale of the region is 651*651*10000 square ft = 4,238,010,000 square ft.
The orientation of the satellite image is oriented north-south.

2. Features in the Preserve area as captured in the imagery.
Most of the images have sensor artifacts at the bottom right corner. To identify the features in the Preserve Area, I picked the image which is generated from the data [image11_2016_09_06.csv]. It has no sensor artifacts at all.

VisualizationsInterpretations
2016 09 06 Changes PlantHealth.jpeg
Band combinations(B4, B3, B2) are mapped to the RGB image channels to create the false-color image as below.
2016 09 06 Floods newLands.jpeg
Band combinations(B5, B4, B2) are mapped to the RGB image channels to create the false-color image as below:
NDVI NIR.jpg

With the NDVI and RVI Value, we can identify the different vegetation.

B2 B4 Cluster.jpg
  • Cluster 1: Common vegetation with lower chlorophyll content.
  • Cluster 2: Road/Newly Land/Soil.
  • Cluster 3: Healthy Plants with higher chlorophyll content which has absorbed the red light strongly.
  • Cluster 4: Waterbody.
  • Cluster 5: Clouds.


3. Features that change over time in these images.

VisualizationsInterpretations
NDVI 3 compare.jpg
In March, Febraury, December, the season of the Preserve area is winter or early spring. During these period, the NDVI value of the waterbody region should not have much difference. However, we can see from the left image that the color of the waterbody in 2014 was green and became light green in 2015, while it turned into red in 2016.
Jun.jpg
Sep WaterClear.JPG
Dec.jpg