Question

Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).
Assertion (A) : Raster data is obtained from satellite images, aerial cameras, and scanned maps.
Reason (R) : Georeferencing allows you to viewed, query, and analyze raster data with other geographic data.
In light of the above statements, choose the most appropriate answer from the options given below.

• A. Both (A) and (R) are true and (R) is the correct explanation of (A).
• B. Both (A) and (R) are true but (R) is NOT the correct explanation of (A).
• C. (A) is true but (R) is false.
• D. (A) is false but (R) is true.

Hint:

To test if Reason (R) explains Assertion (A), read them together using 'because': "Raster data is obtained from satellite images... because georeferencing allows you to view and analyze it." This makes it clear that while both are true, there is no causal relationship between them.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
In Geographic Information Systems (GIS), spatial data is stored in two primary formats: vector data (points, lines, polygons) and raster data (grids of pixels).

Step 3: Detailed Explanation:
Let us evaluate both statements individually:
- Assertion (A): This statement is correct.
Raster data represents the real world using a matrix of cells (pixels) organized into rows and columns, where each cell contains a value representing information (such as temperature or elevation).
This data is typically captured by digital sensors on satellites, aerial cameras on airplanes or drones, or by scanning physical paper maps.
- Reason (R): This statement is also correct.
Raw raster data often lacks real-world spatial coordinates.
Georeferencing is the process of aligning this raster data with a known coordinate reference system (CRS).
Once georeferenced, the raster dataset can be overlaid, queried, and analyzed alongside other spatial datasets (such as vector layers of roads or boundaries) in a GIS environment.
- Evaluating the Relationship: Although both statements are true, (R) is not the correct explanation of (A).
The capacity to georeference and analyze raster data (R) does not explain *why* or *how* raster data is physically captured by satellite sensors or aerial cameras (A).
Thus, both statements are true but (R) is not the correct explanation of (A).

Step 4: Final Answer:
The correct option is (B) as both statements are true but (R) is not the correct explanation of (A).