Direct measurements can be difficult to obtain, so scientists use satellites to observe the cryosphere and to monitor changes.

Over the years, the satellites have monitored Soviet nuclear missile silos and clandestine Libyan chemical weapons plants.

Perhaps American spy planes and satellites had not been monitoring the graves as promised.

The satellite monitors compliance with arms-control treaties among other intelligence-gathering tasks.

He also showed how satellites can monitor luminescence levels to monitor crops (growth rates, water conditions and harvest timing).

The satellite continuously monitored weather events and relayed this meteorological data from over 10,000 surface locations into a central processing center.

Each morning the Joint Reconnaissance Schedule Committee meets to determine what the satellites will monitor over the next 24 hours.

Cheaper, nonstealthy satellites can monitor hard-to-reach locations more cost-effectively.

The latest satellites monitor bad weather around the clock, particularly convective rainstorms, thunderstorms and hailstorms.

Although satellites monitor the radiation dose, there is currently no system for notifying the public.