Optical–IR Bands – Identify the incorrect range name In the optical and infrared portion of the electromagnetic spectrum, which of the following named ranges is incorrect with respect to its wavelength limits?

Introduction / Context:
Remote sensing divides the spectrum into named regions for convenience. In the optical–IR, the typical partitions are visible (VIS), near-infrared (NIR), short-wave infrared (SWIR), and thermal infrared (TIR). Mislabeling a range leads to confusion in sensor selection and data interpretation.

Given Data / Assumptions:

• Approximate, widely used ranges: VIS ~0.4–0.7 μm, NIR ~0.7–1.0 μm (sometimes to 1.3 μm), SWIR ~1.3/1.5–2.5 μm, and TIR typically ~8–14 μm (longwave window).
• Naming conventions vary slightly among texts, but microwave is far longer in wavelength.

Concept / Approach:

Microwave wavelengths are much longer (centimetres to millimetres, about 1 mm to 1 m). The 3–8 μm region is part of the mid/thermal infrared, not microwave. Thus, anything called “microwave infrared” for 3–8 μm is incorrect terminology.

Step-by-Step Solution:

Verification / Alternative check:

Sensor band guides and spectral libraries classify 8–14 μm as TIR; microwaves are >= 1 mm in wavelength.

Why Other Options Are Wrong:

They are not strictly wrong within common educational conventions; the key incorrect label is “microwave infrared”.

Common Pitfalls:

Conflating near, short-wave, mid, and thermal IR; using sensor-specific bands to define universal boundaries.

Final Answer:

Microwave infrared: 3.0 μm to 8.0 μm