The NigeriaSat-X is one of two Earth observation satellites that the country recently launched.

这颗尼日利亚卫星-X是该国最近发射的两颗地球观测卫星中的一颗。

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Penny Mordaunt told MPs during business questions on 8 December 2011 that earth observation satellites were "critical" in helping developing countries manage humanitarian and environmental crises.

BBC: Business questions

It can acquire high-resolution data, especially in the steeply sloping coastal areas, where the radar altimeters flown on many other Earth observation satellites struggle to see important details.

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At the moment, the earth-observation satellites which employ microwaves generally use short-wavelength radiation, because this provides more detailed images.

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