midterm exam Flashcards
may help in capturing fine detail, but
at a cost
Fine spatial resolution
Refers to the specific wavelength intervals in the
electromagnetic spectrum that a sensor can record
SPECTRAL RESOLUTION
High spatial resolution
0.6 -4 m
the revisiting frequency of
a satellite sensor for a specific location
temporal resolution
2-3 days depending on Latitude(revisit time)
SPOT-5
are collected by the image
sensors (e.g. CCD, CMOS) and
accumulates charge proportional to
intensity of radiation
Photons
1-3.5 days depending on Latitude(revisit time)
QuickBird
12-bit (4096 levels
Landsat 8
spectral resolution
High :?
Medium :?
Low :?
220
3 -15 bands
3 bands
increasing data’s
intelligibility as a representation of the object being
sensed
Display and Enhancement
is a representation of a two-dimensional
array of so-called picture elements or pixels. It contains a
fixed number of rows and columns of pixels.
Digital Image
extracting
meaningful patterns from the data
Classification and Information Extraction
ability of imaging system to
record fine detail in a distinguishable manner
Resolution
High temporal resolution:?
Medium temporal resolution:?
Low temporal resolution:?
< 24 hours -3 days
4 -16 days
> 16 days
Low spatial resolution
30 -> 1000 m
It refers to the size of the smallest object that can be
resolved on the ground
spatial resolution
defines smallest area viewed by sensor
IFOV
Each band is treated separately
BAND SEQUENTIAL
Ability of sensor to record many levels of brightness
radiometric resolution
additive colors
Blue, green, red primarie
can be
added, subtracted,
multiplied, divided and
subjected to statistical
manipulation
Brightness
Pixels not completely occupied by
single, homogeneous category
SPATIAL RESOLUTION-MIXED PIXELS
is the time interval allowing accumulation of
enough photons to generate strong signal
Dwell time
It establishes the lower limit for level of spatial detail
IFOV
Each pixel has an________ (represented by a digital
number) and a _________ (referenced by its row
and column numbers)
intensity value, location address
Values for all 4 bands
are written before the
values for the next
pixel
BAND INTERLEAVED BY PIXEL
Medium spatial resolution
4 -30 m
Fineness of spatial detail visible in the image
spatial resolution
number of mixed pixels
increase with respect to pure background and pure interior
pixels
Coarser spatial resolution
Ability of sensor to define fine wavelength intervals
SPECTRAL RESOLUTION
Landsat-7/8 (revisit time)
16 days
removal of systematic errors in data
Pre-processing
Depends on altitude, speed, and sensitivity of detectors
Dwell time
record scene using only
few brightness levels or few bits (e.g., 8 bit 2^8BVs (0
255)
Coarse radiometric resolution
A collection of techniques for the manipulation of
digital images by computers.
digital image processing
subtractive color
Cyan, magenta, yellow
are the smallest individual element in an image,
holding quantized values that represent the brightness of a
given color at any specific point.
Pixels
approximately 3 days at 40°Latitude(revisit time)
IKONOS
Refers to the smallest change in intensity level that can be
detected by the sensing system
radiometric resolution
Line values for all 4 bands
are written before the
values for the next line
BAND INTERLEAVED BY LINE
