Question

What is change detection? Describe various classification based methods of change detection.

19 Jan 2026
Answer :
Word Count : 482
Change detection in remote sensing refers to the process of identifying differences in the state of an object or phenomenon by observing it at different times. It is a critical technique used in environmental monitoring, urban planning, agriculture, forestry, and disaster management. The primary goal of change detection is to quantify, locate, and analyze the changes that occur over time in the Earth's surface by comparing multi-temporal satellite or aerial images. These changes can be natural, such as vegetation growth, soil erosion, or water level fluctuations, or anthropogenic, such as urban expansion, deforestation, and land use changes. Accurate change detection requires high-quality, pre-processed images that are geometrically aligned, radiometrically corrected, and temporally consistent to minimize errors caused by differences in sensor calibration, atmospheric conditions, and seasonal variations. Classification-based methods of change detection involve categorizing land cover types in multi-temporal images and then comparing these classifications to identify changes. These methods can be broadly divided into two approaches: post-classification comparison and direct multi-date classification. In post-classification comparison, each image acquired at different times is independently classified using techniques such as supervised classification, unsupervised classification, or hybrid approaches. Supervised classification
_________ _______ _________ ___ ___ ____ ________.
_______ __________ ________ _____ ________ ___ ______ __________ _______.
_______ ______ ______ ____ _________ ___ ____ _________ _______ ______ _____.
_________ ___ _____ ______ _______ ______ _______ ______ __________ ______ ____ __________.
____ ____ ____ _______ _____ _______ __________ _____.
______ __________ ____ _______ _____ ______ ____.
____ ____ ____ ______ ____ _____ _______ _________.
__________ ___ ____ _________ ____ ________ _____.
__________ __________ _________ _________ ____.
_______ ___ _____ _____ ___.
_______ __________ ____ _______ ________ ________ ___ ___ _________ ______.
______ _________ ______ ______ ________ ___.
____ _______ _______ ______ ____ ____ _____ __________ _________ _______ _________ ______.
________ ______ ___ ________ __________ _______.
_______ ___ __________ __________ ___ _________.
________ _________ ________ ______ _______ __________ ______ ________ ____.
___ ________ ______ _____ ________ _________.
________ ________ ______ ____ ____ ________ __________ _________ _____ ____.
______ _____ ________ _____ _______ ____ _________ ___ _________ _________ __________.
_________ ______ ___ _________ ____ ____ _________ ________ ___ ______ ___ _________.
__________ __________ ______ _________ _______ ____ _____.
___ _________ ______ __________ ___ ________ ________ ________ _________ ____ ____.
______ ________ ________ _________ ______ _______ ____.
________ ______ ___ _______ ______ __________ _________ _______ _______ _________ ___.
___ __________ ____ ___ __________ __________ _____ _____ _______ _______.
_______ ______ _______ _________ ______ ____ ___.
___ ___ ______ _____ ____.
____ _____ ________ _________ ______ ____ _____ _____ _________.
__________ ___ ___ ________ ______ ___ ________ ____ _______.
_____ ___ ____ ______ _________ _____ ____ ___ _____.
______ ____ ________ ____ _______ ____.
______ _______ ___ _______ ________ _______ _________ _______ ______.
___ _____ _______ _____ ________.
______ ___ ___ ________ _________ ______ __________ ________ ________ _________ ______.
________ ________ ______ ____ _____ _________ _______ ____.
________ _______ ______.
IGNOU ACADEMY
Your IGNOU journey, made easier.
  • Solved Assignments
  • Study Notes
  • Guess Papers
  • Question Papers
Skip in 10
Top
📞
Call Support Instant phone assistance IGNOU MGY 5 2026 - What is change detection? Describe various classification based method | IGNOU Academy
→
🟢
WhatsApp Chat Fast live messaging
→
Email Us Business enquiries & support
→