AULÃO OBA - IMAGENS DE SATÉLITES

Summary

This video explains the practical applications of satellite imagery in environmental monitoring, focusing on the Amazônia 1 satellite's role in tracking deforestation. The script covers two main problems: calculating the real area of deforestation using pixel resolution data and determining the average annual deforestation rate. Additionally, it explores the importance of satellite resolution in capturing detailed images and calculating areas represented by pixels, with examples related to land monitoring. The video highlights how satellite data is crucial for timely action against deforestation and land misuse, providing an educational insight into the intersection of technology and environmental conservation.

Takeaways

• 😀 The Amazônia 1 satellite, launched in February 2021, helps in monitoring deforestation in Brazil by capturing images every five days.
• 😀 Each pixel in the satellite's images represents an area of 60 meters by 60 meters on Earth, allowing for detailed analysis of large regions.
• 😀 The deforestation area in the image was represented as a rectangle measuring 1.5 cm by 5.6 cm, which was converted into real-world kilometers squared.
• 😀 To find the real area of deforestation, the image's pixel dimensions were converted, resulting in a deforested area of 75.6 km².
• 😀 The deforestation rate was calculated by dividing the total area (75.6 km²) by the 20 years between the two images, yielding an average of 3.78 km² per year.
• 😀 Satellites with different spatial resolutions can capture various levels of detail; a 30-meter resolution, for example, cannot identify objects smaller than 30 meters.
• 😀 A satellite's sensor resolution impacts its ability to discriminate objects based on their size, with higher resolutions providing more detailed images.
• 😀 The images from the satellite include pixels, with the number of pixels directly affecting the level of detail observed in the final image.
• 😀 A camera's resolution is determined by how many pixels it has; higher pixel counts result in clearer images that can identify smaller objects.
• 😀 In a case study, the deforested area of 90m by 90m was found to occupy 225 pixels on a satellite image, illustrating how pixel count is used to measure real-world areas.

Q & A

What is the main purpose of the Amazonia 1 satellite?

The Amazonia 1 satellite is designed for Earth observation, specifically to monitor deforestation and other environmental changes. It helps generate rapid alerts about deforestation, enabling quicker responses to illegal logging and land use changes.

How often does the Amazonia 1 satellite capture images of the same area?

The Amazonia 1 satellite captures images of the same area every five days, allowing for frequent updates and monitoring of the environment.

What does each pixel in the Amazonia 1 satellite image represent?

Each pixel in the Amazonia 1 satellite image represents a 60m x 60m area on the Earth's surface.

How is the real-world area of deforestation calculated from the satellite images?

To calculate the real-world deforested area, you multiply the number of square centimeters in the image by 9 (since 1 cm² on the image represents 9 km² on the Earth's surface). For example, 8.4 cm² corresponds to 75.6 km² of deforestation.

What is the average annual deforestation rate for the region shown in the images?

The average annual deforestation rate is calculated by dividing the total deforested area (75.6 km²) by the number of years (20 years), which results in an average rate of 3.78 km² per year.

What is the significance of satellite resolution in monitoring environmental changes?

Satellite resolution determines the level of detail visible in an image. Higher resolution allows for the identification of smaller objects, such as individual vehicles, while lower resolution is better suited for observing larger regions like forests.

How does the resolution of a satellite affect the size of objects it can detect?

A satellite with lower resolution (e.g., 50m or 100m per pixel) will only detect larger objects, such as vast land areas, whereas higher resolution satellites (e.g., 0.5m per pixel) can detect smaller objects like vehicles and buildings.

How do you calculate the total area covered by an image from a satellite with a given pixel count and resolution?

To calculate the total area covered, multiply the number of pixels by the area each pixel represents. For example, if a satellite image has 16 million pixels and each pixel represents 36 m², the total area is 576 million m², or 576 km².

In the second part of the script, how do we determine the number of pixels needed to represent a deforested area of 90m x 90m?

To determine the number of pixels, divide the dimensions of the deforested area (90m x 90m) by the pixel size (6m x 6m). This results in 15 pixels in both width and height, or 225 pixels in total.

What is the concept of a 'hectare' and how is it related to the area described in the video?

A hectare is a unit of area equivalent to 10,000 square meters or a 100m x 100m square. In the script, it is mentioned that the area of 90m x 90m is close to one hectare, which means it is nearly 8,100 m² in size.