Image Acquisition

Question 1

Aerial Photography operates in…

Answer 1

-Visible and NIR

Metric Cameras - vertical optical axis
V high geometric fidelity

Question 2

Photogrammetry is…

Answer 2

Determining geometric properties of objects from photos

Question 3

Interpretive Photogrammetry

Answer 3

Identification and systematic analysis of ground based object info

• Qualitative
• Distance between 2 points on plane parallel to image plane = distance in imagery plane

Question 4

Stereo Photogrammetry

Answer 4

3D coordinate estimated from 2+ images from different positions
-Calculation requires at least 3 known object points

Question 5

Electro-optical (V/NIR)

Answer 5

Spectral range similar to aerial photography
Digital detection - 2D Photodiode array (CCD’s)
Deployed from - aircraft + satellites

Eg
Landsat
ASTER
MODIS
IKONOS
SPOT

Question 6

Electro-optical (V/NIR)

• SCANNING
  1. ) Step-stare
  2. ) Pushbroom imaging
  3. ) Whiskbroom

Answer 6

1. ) EMR focused on 2D CCD array + imaged instantaneously
2. ) EMR focused onto 1D array + viewing in narrow strip
3. ) EMR focused onto single element (Most common)

Question 7

Most VIR imagers are…

Answer 7

multispectral, some hyperspectral

Question 8

Landsat
1-4
4-5
7 (Enhanced Thermatic Mapper)

Answer 8

multispectral (G,R,NIR,IR)
Thermatic mapper
Panchromatic

Question 9

SPOT improves on…

Answer 9

Landsat 7
with off nadir jobs
HRV sensors (Higher Spatial Res)

Question 10

SPOT vs Landsat

Answer 10

SPOT = much smaller image area

Question 11

ASTER

Answer 11

Advanced Spaceborne Thermal Emission and Reflection Radiometer

Japan/US effort - multispectral (14) + Back looking for stereo

Question 12

CERES

Answer 12

Clouds and the Earth’s Radiant Energy System

Question 13

MISR

Answer 13

Multi-Angle Imaging Spectroradiometer

Question 14

MODIS

Answer 14

Moderate-resolution Imaging Spectroradiometer

36 band multispectral

Question 15

MOPITT

Answer 15

Measurement of Pollution in the Troposphere

Question 16

IKONOS

Answer 16

V fine resolution
0.83m for Panchromatic
4m for multispectral

Question 17

GeoEye-1

Answer 17

2x resolution of IKONOS

Question 18

Thermal IR systems use….

Answer 18

wavelengths 8-14 micrometers

Question 19

TIR systems are used for

Answer 19

surface temps

coarser spatial resolution than Landsat

Question 20

AATSR

Answer 20

Advanced along Track Scanning Radiometer
Maps sea surface temp
Doesn’t penetrate clouds

Question 21

Passive microwave detects…

Answer 21

black-body radiation in MW part of spectrum
Wavelength = 3-6 m
Penetrates clouds
V coarse resolution

Question 22

Laser Ranging uses emission of…

Answer 22

pulse of light and time taken for reflection to return

Vertical resolution 0.1m possible

Question 23

Satellite laser altimetry uses….

Answer 23

IR and visible

GLAS = Geosciences Laser Altimeter System

Question 24

Radar Altimetry is similar to…

Answer 24

Laser altimetry
Can observe through clouds
Waveform= info about roughness

Slope error can be a factor

Question 25

Radio-echo sounding used for….

Answer 25

englacial and subglacial properties

Question 26

Imaging radar/ scatterometry is transmitting of…

Answer 26

MW which are scattered and reflected

Question 27

Scatterometry involves the…

Answer 27

emission of a pulse which is scattered back to a sensor

Question 28

SAR=

Answer 28

Synthetic Aperture Radar

Question 29

SAR uses…

Answer 29

forward motion to synthesise very long antenna = greater resolution

Question 30

Forshortening results in…

Answer 30

strange geometry due to measure of travel time not angle