Analog and Digital Signals

These flashcards cover the key concepts related to analog and digital signals, including definitions and differences.

What characterizes analog signals?

Analog signals are smoothly changing electrical signals that directly represent something in the real world.

What turns a bit “off”?

0/Black

What turns a bit “on”?

1/White

What properties of sampling size and frequency produce a better digital approximation of an analog black and white image?

More frequent sampling (more boxes), smaller sample size (smaller boxes)

What signals are more reliable for sending larger amounts of information for distances?

Digital

To ___ information is to convert that given information to a particular form, analog or digital.

Encode

To ___ information is to translate received data back into its original format.

Decode

Are sound waves mechanical or electromagnetic?

Mechanical

Do sound waves require as medium?

Yes

Are light waves mechanical or electromechanical?

Electromagnetic

Do light waves require a medium?

No

What is the top of a wave?

Crest

What is the bottom of a wave?

Trough

What is the distance between waves?

Wavelength

What is the wave height/2?

Amplitude

Is a higher amplitude in a sound waves louder or quieter?

Louder

Is a lower amplitude in a sound waves louder or quieter?

Quieter

Is a higher frequency in a sound waves lower or higher pitch?

Higher

What is the square of the amplitude proportional to?

Energy transmitted by a wave

What is the frequency of a wave proportional to?

Energy of a wave

What is an echo an example of?

Reflection

What is looking in a mirror an example of?

Reflection

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Absorption

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Reflection

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Transmission

What is sun waves absorbing into the ground an example of?

Absorption

What is the color black absorbing light an example of?

Absorption

What is light bending as it passes through prism an example of?

Refraction

What is a pencil looking bent in water an example of?

Refraction

What is a knock on the door an example of?

Transmission?

What is sun through a window an example of?

Transmission

What is radio waves transmitting information an example of?

Transmission

Does white or black reflect more energy?

White

What would you want the wave behaviors of a stealth craft be, and what materials?

Absorption, soft materials, black paint, sharp edges

How are satellites used for communication?

Text, call, tv, radio, etc.

How are satellites used for navigation?

GPS, Google Maps, google earth, etc.

What are some examples of data that can be collected by satellites?

Deforestation, urban sprawl, fire cover, weather patterns

Landsat instruments primarily measure light that is ___ from the Earth’s surface.

Reflected

What type of signals do satellites use to communicate?

Digital signals, radio waves that transfer information

Describe how waves get from the sun to our computers.

Light waves transmitted to the ground, some absorbed, others reflected to a satellite, which then either transfers it down to Earth or to another satellite, then to relay stations on Earth, and it then goes to computer for use.

Is a lower frequency in a sound waves lower or higher pitch?

Lower

How do digital signals differ from analog signals?

Digital signals are encoded in a specific form that represents discrete values, making them more reliable over long distances.

What is the effect of noise on analog signals?

Analog signals are impacted by noise, which can distort the original information.

Define the process of encoding information.

Encoding is the process of converting information into a particular form, whether analog or digital.

Define the process of decoding information.

Decoding is the transformation of received data back into its original format.

Why are digital signals often favored for communication over distances?

Digital signals are more reliable for transmission over long distances compared to analog signals.