Photogrammetry and Multispectral Remote Sensing - PowerPoint PPT Presentation

Loading...

PPT – Photogrammetry and Multispectral Remote Sensing PowerPoint presentation | free to download - id: 41feb3-Y2MzN



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Photogrammetry and Multispectral Remote Sensing

Description:

What is Photogrammetry Photogrammetry is the art and science of making accurate measurements by means of aerial ... (digital images) Aerial photographs were the ... – PowerPoint PPT presentation

Number of Views:447
Avg rating:3.0/5.0
Slides: 29
Provided by: Hong1
Learn more at: http://www.utsa.edu
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Photogrammetry and Multispectral Remote Sensing


1
Photogrammetry and Multispectral Remote Sensing
  • Lecture 3
  • September 8, 2004

2
What is Photogrammetry
  • Photogrammetry is the art and science of making
    accurate measurements by means of aerial
    photography
  • Analog photogrammetry (hard-copy photos)
  • Digital photogrammetry (digital images)
  • Aerial photographs were the first form of remote
    sensing imagery.
  • Differences between photogrammetry and Remote
    Sensing are that photographs are
  • Black and white (1 band) or color (blue, green,
    red, and IR)
  • Wavelength range of 0.3-1.0 ?m
  • Use cameras
  • One type of remote sensing imagery

3
Types of vantage points to acquire photographs
  • Vertical vantage points
  • Low-oblique vantage points
  • High-oblique vantage points

4
Vertical Aerial Photography
Goosenecks of the San Juan River in Utah
Jensen, 2000
Most are vertical aerial photography
5
Low-oblique Aerial Photography
Low-oblique photograph of a bridge on the
Congaree River near Columbia, SC.
Jensen, 2000
6
High-oblique Aerial Photography
High-oblique photograph of the grand Coulee Dam
in Washington in 1940
Jensen, 2000
7
Color Science
additive
  • Additive primary colors
  • Blue, Green, and Red
  • Subtractive primary colors (or complementary
    colors)
  • Yellow, Magenta, and Cyan
  • Filters (subtract or absorb some colors before
    the light reaches the camera)
  • Red filter (absorbs green and blue, you can red)
  • Yellow (or minus-blue) filter (absorbs blue,
    allows green and red to be transmitted, which is
    yellow)
  • Haze filter (absorbs UV)

Subtractive
8
Types of photographs
  • Black and white photographs
  • Panchromatic (minus-blue filter used to eliminate
    UV and blue wavelengths)
  • IR (IR-sensitive film and IR only filter used to
    acquire photographs at 0.7- 1.0 ?m )
  • UV (at 0.3-0.4 ?m, low contrast and poor spatial
    resolution due to serious atmospheric scattering)
  • Color photographs
  • Normal color (Haze filter used to absorb UV and
    create true color 0.4-0.7 ?m, or blue, green,
    red)
  • IR color (Yellow filter used to eliminate blue
    and create IR color of 05-1.0 ?m, or green, red,
    IR)
  • 4 bands (blue, green, red, and IR)

9
Satellite photographs
  • Extensive collections of photographs have been
    acquired from manned and unmanned Earth or
    Mars-orbiting satellites.
  • Beginning in 1962, USA acquired photographs of
    moon for Apollo mission
  • 1995, USA declassified intelligence satellites
    photographs of Sino-Soviet acquired 1960-1972 at
    2-8 m resolution.
  • 2000, Russia launched satellites acquired
    photographs of 2 meter resolution
  • 1999, Mars Global Surveyor of NASA acquires Mars
    photographs with 1.2 12 m resolution
  • 2003, Mars Express of ESA acquires Mars
    photographs with 2 and 10 m resolution.

10
Flightline of Vertical Aerial Photography
Jensen, 2000
11
Block of Vertical Aerial Photography
Jensen, 2000
12
Block of Vertical Aerial Photography Compiled
into an Uncontrolled Photomosaic
Columbia, SC Original scale 16,000 Focal
length 6 (152.82 mm) March 30, 1993
Jensen, 2000
13
Scale of photographs
  • Image size/ real world size
  • S ab/AB
  • Focal length/ altitude above ground
  • S f / H

14
Scale (2)
1 12
S f / (H-h)
0.012/ (6 x 12) 1/6000
Max scale, minimum scale, and average or nominal
scale
15
Orthophotographs and digital orthoimagery
  • Photograph after corrected by ground control
    points (x, y, z) or digital elevation model (DEM)
    called orthophotograph, orthophoto, or digital
    orthoimagery.
  • Not as photographs, they have different scales in
    different terrain relief, orthophotos have only
    one scale, no distortion, and have true distance,
    angle, and area. Orthophotos can be directly
    input into GIS as basemap or for interpretation.

16
Extraction of Building Infrastructure based on
orthophotographs
17
Orthophotograph draped over a DEM
18
Kevin Hankinson will share his experience in
acquiring aerial photos
19
Multispectral Remote Sensing
  • Multispectral remote sensing is defined as the
    collection of reflected, emitted, or
    backscattered energy from an object or area of
    interest in multiple bands of electromagnetic
    spectrum while Hyperspectral remote sensing
    involves data collection in hundreds of bands.
  • Instead of cameras and 1 or 4 bands for
    photogrammetry, Remote sensing use detectors that
    are sensitive to hundreds of bands in the
    electromagnetic spectrum. Measurements made by
    detectors are always stored in a digital format.

20
Overview
Jensen, 2000
Energy detected is recorded as an analog
electrical signal
21
Remote Sensing Raster (Matrix) Data Format
Y axis
Jensen, 2000
22
  • Discrete Detectors and scanning mirrors
  • - MSS, TM, ETM, GOES, AVHRR, SeaWiFS, AMS,
    ATLAS
  • Linear Arrays
  • - SPOT, IRS, IKONOS, ORBIMAGE, Quickbird, ASTER,
    MISR
  • Liner and area arrays
  • - AVIRIS, CASI, MODIS, ALI, Hyperion, LAC

Detector configurations breaking ou the spectrum
Jensen, 2000
23
Sabin, 1997
Liner arrays and area arrays
Discrete Detectors and scanning mirrors
Field of View (FOV), Instantaneous Field of View
(IFOV) Dwell time is the time required for the
detector IFOV to sweep across a ground cell. The
longer dwell time allows more energy to impinge
on the detector, which creates a stronger signal.
24
Landsat satellite series
MSS TM ETM 0.5-0.6
0.45-0.52 0.45-0.52 0.6-0.7 0.52-0.60
0.52-0.61 0.7-0.8 0.63-0.69
0.63-0.69 0.8-1.1 0.76-0.90
0.78-0.90 10.4-12.6 1.55-1.75 1.55-1.75
10.4-12.5 10.4-12.5
2.08-2.35 2.09-2.35
0.52-0.90 79m 30
30 240m 120 60
15 6 bits 8
8 103 m/c 99 99 18 days
16 16 919km 705
705 185km 185 185
Jensen, 2000
25
Inclination (99º) of the Landsat Orbit to
Maintain A Sun-synchronous Orbit
MSS 99º TM 98.2º
  • Sun-synchronous orbit mean that the orbital plane
    precessed around Earth at the same angular rate
    at which Earth moved around the Sun
  • The satellite cross the equator at approximately
    the same local time (930 to 1000 am)

Jensen, 2000
26
Todays Landsat 7 orbits and acquisition
http//landsat7.usgs.gov/pathrows.php
27
TexasView Remote Sensing Consortium
Free Landsat 7 imagery available from TexasView
http//www.texasview.org/pages/archives/html/lands
at.html
28
About the lab setup and a DEMO of ENVI
About PowerShow.com