Intro and EM Flashcards
What is remote sensing?
It is the science of acquiring information about the earth surface without getting in contact with it.
Energy travels in
electromagnetic waves
What are the two properties of every wave?
Wavelength and frequency
The distance between two successive crests is
wavelength
The number of cycle of wave passing a fixed point per unit of time is
frequency
The longer the wavelength the lower/higher the frequency?
lower
The electro magnetic spectrum ranges from Gamma to ….
microwave
What is the shortest wave length?
Ultra violet
The primary colors from which other colors on the visible light portion of the electromagnetic spectrum can be obtained are…?
Blue, green and red
Which wave on the spectrum has the longest wavelength and the shortest frequency?
Radio waves
I am shorter than radio waves but I have a higher frequency than that bitch, 🙄 who am i?
Microwaves
The wave that is applied in RIS for thermal imaging and communication is called?
Infrared
The type of wave applied in germicidal lamps, black light and UV spectroscopy is called?
Ultraviolet waves
Shortest in the spectrum with the highest frequency is
Gamma rays
Applied in medical imaging, security scanning and materials testing is
X-rays
What is spectral resolution?
ability of the sensor to separate EM into small intervals (bands)
Three main types of sensors used are
Optical, Radar and LiDAR
With the passive type of remote sensing, what is the source of energy?
The sun, earth or atmosphere
Source of energy in active remote sensing is
remote sensor system
The angle between the sun and a line perpendicular to a surface is called
solar incidence angle
The solar incidence angle for a horizontal surface is called
Solar zenith angle
The finer the spectral resolution the ….., the wavelength range for a particular channel or band
narrower
The length of time for a satellite to complete one entire orbit circle is called
Temporal resolution
The two basic theories that describe EMR are
the wave and particle theory
EM energy is composed of discrete units called
photons or quanta
The theory that is most useful in quantifying the amount of energy measured by the sensors is
Particle theory
The wavelengths at which the radiation can penetrate the atmosphere with the little interference are called
Atmospheric windows
Recording devices that measure emitted radiation or sound is
Sensor
The type of sensor that provides its own energy source for illumination is called an/a
Active sensor
What are the three forms of interactions between radiation and the target?
reflection, absorption and transmission
The unpredictable diffusion of radiation by particles in the atmosphere is called
Scattering
What type of scattering is responsible for the blue and red skies?
Rayleigh
……..results in the effective loss of energy to atmospheric constituents.
absorption
Where the angle of reflection equals the angle of incidence is
Specular
Where reflectance is equal in all direction is
diffuse
The ratio of reflected energy to incident energy as a function of wavelength is called
spectral reflectance
The light energy per unit time impinging on a surface, normalized by the surface area is called
irradiance
……is simply how much light the instrument sees from the object being observed.
radiance
When radiation is redirected from its original path, we call it
scattering
When ozone, CO2 and water vapor absorbs radiation, we call it
absorption
The two main interactions in the atmosphere are
scattering and absorption
Smooth surface bouncing radiation in one direction is
specular
rough surface bouncing energy in all directions is
diffuse
Leaves in summer have more chlorophyll hence they absorb …… wavelength reflecting green.
Red and blue
In Autumn, chlorophyll is reduced hence it exhibits …..
yellow to red color
Out of the five human body sensors, how many can be considered as a form of remote sensing?
3
The EM spectrum is divided into narrow wavelength intervals called
band or channel
Energy detected are stored in
bands
Bands are numbered from?
1
