Remote sensing : Progm (ENVI) Q1: Note how different surface features are highli
ID: 112329 • Letter: R
Question
Remote sensing : Progm (ENVI)
Q1: Note how different surface features are highlighted in different bands. Why?
Q2: Which bands represent “true color” and why?
please answer in a paragraph, ty.
Open 3 bands (Red, Green, Blue) to show false color image. Available Bands List File Options a bhtmref.img 1. Press RGB button. o TM Band 1 (0.4850) o TM Band 2 (0.5600) o TM Band 3 (0.6600) o TM Band 4 (0.8300) o TM Band 5 (1.6500) TM Band 7122150) 2. Left click on "TM Band 1 (0.4850)" in available band list => Press "TM Band 1 (0.4850)", "TM Band4 (0.8300)", and "TM Band 7 (2.2150)"->Press Load RGB button. o Map Info Q1: Note how different surface features are highlighted in different bands. Why? Q2: Which bands represent"true color" and why? Gray Scale RGB Color R TM Band 1 (0.4850pbhtmef. img (1 #2 (R:IMBand 1,GTM Band 4,01: TM Band 7)hhtnveang Fle Overlay Enhance Tools Window (1 #2 (R:IMBand Z.GTM Band SJkIMBandT)Ihtmredang Fle Overlay Erhance Tools Window ADI Fle Overlay Erhance Tools Window CB TMBand 7 (2.21 Dims 512 x512(Be) [BSQ Load RGB | Display #1 img Bands 1,4,7 True Color Bands 2, 5,7Explanation / Answer
Q1.
Band 1 (0.45 - 0.52u m) gives increased penetration of water bodies and it distinguishing soil and rock surfaces from vegetation and for detecting cultural features.
Band 2 (0.52 - 0.60u m) is sensitive to water turbidity differences. It has separated vegetation (forest, croplands with standing crops) from soil. In this band barren land, urban areas and roads and highways are appeared as brighter (lighter) tone, but forest, vegetation, bare croplands, croplands with standing crops have appeared as dark (black) tone.
Band 3 (0.63 - 0.69u m) is sensitive to a strong chlorophyll absorption region and strong reflectance region for most soils. It has differentiated vegetation and soil. But it couldn’t separate water and forest. Both the forest land and water are appeared as dark tone. This band has tinted barren lands, urban areas, street pattern in the urban area and highways.
Band 4 (0.76 - 0.90u m) works in the best spectral region to distinguish the vegetation varieties and conditions. Water is a strong absorber in the near IR region, so this band defines water bodies, separate dry and moist soils. Croplands and grasslands showed brighter tone than the forest in this band and it also separated croplands from bare croplands. This band is useful for crop identification and highlights soil-crop and land-water contrast.
Band 5 (1.55 - 1.75u m) is sensitive to the amount of water in plants. It separated forest lands, croplands, water body definitely. Forests showed a comparatively darker tone than the croplands (light gray).This band separated water body from barren lands, croplands, and grass lands.
Band 7 (2.08 -2.35u m) separated land and water sharply. It is a strong water absorption region and strong reflectance region for soil and rock. In this band urban area, croplands, highways, bare croplands showed as bright tone and water body, forest showed as dark tone.
Q2.
Landsat measures different varieties of frequencies in the electromagnetic. Each range of frequencies is known as a band; Landsat numbers red, green, and blue sensors as 4, 3, and 2, when combine these three get a true-color image.
In this band Vegetation appears in red, urban areas are cyan blue, and soils appears in dark to light browns. Ice, snow and clouds are shown as white or light cyan. Coniferous trees appeared as dark red than hardwoods. This is a very common band combination and is very useful for vegetation studies, observing drainage and soil patterns and various stages of crop growth.