What is the main idea of the passage?

Crop satellites reveal large-scale patterns across wavelengths, but their signals require local evidence and judgment for diagnosis and action. (The passage explains sensing, uses, confounding factors, scale tradeoffs, and interpretation.)

Why should an unusual warm patch be checked in the field?

Several conditions can affect the signal, so warmth alone does not identify one cause. (The third paragraph says the remote pattern is not a diagnosis and lists possible influences.)

What does “resolution” mean here?

the amount of spatial detail a sensor can distinguish (The discussion of several conditions mixing inside one pixel shows resolution concerns spatial detail.)

What can block a satellite’s view of the ground?

clouds (The third paragraph directly states that clouds can hide the ground.)

The Satellite That Watches Crops: Level 5 Reading Comprehension Questions

A crop satellite does not see a field as a farmer does. Its sensors measure energy reflected or emitted from patches of Earth's surface. Different wavelength bands reveal different features, including color, near-infrared reflection, surface temperature, and moisture-related signals. Healthy leaves absorb much visible red light for photosynthesis while reflecting strongly in near-infrared wavelengths. Analysts combine those measurements into vegetation indices. Repeated images can show where plant cover is changing faster or slower than expected. Thermal observations may reveal unusually warm areas associated with water stress.

The signal is not a diagnosis by itself. Bare soil, crop type, growth stage, clouds, smoke, viewing angle, and sensor resolution can alter the pattern. One image may mix several conditions inside a single pixel. A farmer or adviser compares satellite evidence with weather, planting records, field visits, and knowledge of local soil.

Orbit creates both reach and delay. A satellite can observe large or remote areas with the same instrument, supporting regional drought assessment and planning. Yet it passes on a schedule, and clouds can hide the ground when a decision is urgent. Aircraft, drones, and field sensors can supply closer or more frequent observations at smaller scales.

Useful monitoring therefore connects scales. A broad image identifies an unusual patch; a person investigates its cause; later images show whether the condition spreads or improves. The satellite does not replace local judgment. It makes patterns visible that are difficult to see while standing among individual plants, then returns those patterns to people who can interpret and act on them.

Comprehension questions