remote Sensing and Communications Practice Quiz

Modern radar uses what region of the electromagnetic spectrum?

• Infrared (IR)

• Visible light

• Microwaves

Which of the following statements are true about how microwaves move from and to a radar sensor? Select all that apply.

• Power of the received energy is the same as transmitted

• The energy spreads over an area that is increasing in proportion to the square of the distance from the source

• Received wavelength is the same as transmitted

With radar, increasing the distance between the transmitter and the subject by a factor of 10 reduces the energy received by a factor of ____.

• 100
• 10000

• 1000

• 1

The changing frequency of a microwave as it moves relative to the observer is called ____.

• Doppler effect
• Kipler effect

• Marina effect

Which of the following statements are true about SAR? Select all that apply.

• SAR produces three-dimensional images

• SAR is undetectable by observers in the area being observed

• SAR operates in two modes: spotlight mode and scan mode

Which of the following statements are true about LIDAR? Select all that apply.

• Observers on the ground can tell when they are being imaged with LIDAR

• Like radar, LIDAR uses microwave waves

• LIDAR uses a laser in the ultraviolet, visible, or IR wavelengths

Which of the following explains angular resolution?

• It defines the ability to distinguish between two sources and is a function of wavelength and aperture diameter in meters

• It describes the smallest linear distance at nadir that can be resolved at a distance and can be calculated by converting the radius to diameter and then multiplying by altitude

How does a reflecting telescope work?

• The user views an image through an eyepiece, which acts as a magnifying glass, and then manipulates the magnification by adjusting the distance between the eyepiece and the lens

• It uses a lens to bend light and form an image

• It uses an array of mirrors that are manipulated to focus and produce images

What is the difference between Spatial and Spectral resolution?

• The relationship between the two is that you can have both types of resolution at the same time

• • Spatial resolution refers to a sensor’s ability to discern between individual objects or the distance between those objects; spectral resolution refers to a sensor’s ability to differentiate between the spectral differences between objects

• They both offer very high resolution

Which of the following is a description of an Active Sensor?

• An active sensor is one that is designed to emit energy toward its target area and then collect the reflected energy as it returns to the sensor

• An active sensor is one that propagates its energy and receives energy 360 degrees

• An active sensor requires precise pointing to transmit and receive data