Question

In the following options, the spectral bands of a remote sensing image are mapped to the colours of the display system. Which one of the following combinations indicates a standard False Colour Composite (FCC)?

• A. Green to Blue; Red to Green; Near Infrared to Red
• B. Near Infrared to Green; Red to Blue; Green to Red
• C. Blue to Green; Green to Red; Red to Blue
• D. Green to Red; Red to Green; Near Infrared to Blue

Hint:

A standard FCC always puts the Near Infrared band on the display's Red channel, which is why healthy vegetation looks bright red in such images.

Answer 1

The Correct Option is A

Step 1: Recall the purpose of a False Colour Composite.
A False Colour Composite (also called a Colour-Infrared or CIR composite) is built by displaying non-visible or visible bands through display guns that are not their natural colour, chosen specifically to make features such as healthy vegetation stand out. It uses the display's Red, Green and Blue channels, but feeds them bands other than the true Red, Green, Blue bands of the scene.
Step 2: State the standard FCC convention.
The universally used standard FCC assigns the Near Infrared (NIR) band to the display's Red channel, the Red band to the display's Green channel, and the Green band to the display's Blue channel. This is written compactly as NIR to Red, Red to Green, Green to Blue.
Step 3: Explain why this convention is chosen.
Healthy vegetation reflects very strongly in the NIR band (due to leaf mesophyll structure) but only moderately in Red and Green. Placing NIR in the Red display channel therefore makes vegetation appear bright red in the composite, which is the signature look of a standard FCC used for vegetation health, land cover, and crop studies.
Step 4: Match this convention to option (A).
Option (A) reads Green to Blue; Red to Green; Near Infrared to Red, which written the other way round is exactly NIR to Red, Red to Green, Green to Blue, matching the standard convention from Step 2.
Step 5: Rule out the remaining options.
Option (B) sends NIR to Green and Red to Blue, which is not the standard mapping. Option (C) uses only the true-colour bands (Blue, Green, Red) with no NIR channel at all, which describes a true colour composite, not an FCC. Option (D) sends NIR to Blue instead of Red, again breaking the vegetation-highlighting convention.
Step 6: Conclude.
Only option (A) reproduces the standard FCC mapping.
\[ \boxed{\text{Standard FCC: NIR} \to \text{Red},\ \text{Red} \to \text{Green},\ \text{Green} \to \text{Blue}} \]