Remote Sensing Terminology
The Landsat program is a series of American satellites that use the visible and infrared parts of the spectrum to record images of the Earth's surface. It is the longest running enterprise for acquisition of satellite imagery, and started back in 1972. The most recent, Landsat 8, was launched in 2013.
Landsat satellites are located in a polar orbit, which allows them to provide images of almost all of the Earth's geography. As the satellite orbits the Earth from pole to pole, it appears to move from east to west because of the Earth’s rotation. This apparent movement allows the satellite to view a new area with each orbit.
Determining land cover has become one of the most common uses of Landsat Imagery and remotely sensing generated images all around the world.
The LiDAR sensor produces a series of point measurements that consists of geographic location (X & Y) and height (Z) of both natural and man-made features, and can be further processed to produce several different products and integrated into a Geographic Information System (GIS).
Click here to learn more about LiDAR
The amount of energy returning to the sensor (known as backscatter) is dependent upon the topography, roughness, and dielectric properties (moisture). Areas of an image with low backscatter appear dark (such as water), while areas of high backscatter appear as light gray levels approximating white shades. By interpreting the various gray tones, textures and patterns, the user can detect information regarding to the regions geologic lithology and structure.
In much of remote sensing, the process involves an interaction between incident radiation and the targets of interest. This is exemplified by the use of imaging systems where the following seven elements are involved. Note, however that remote sensing also involves the sensing of emitted energy and the use of non-imaging sensors. Click here to learn more about Remote Sesning
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Below is a simple EASI script that when used with the MODEL command in PCI will clip the unnecessary excess portions of an air photo mosaic created from Ortho Engine to an irregular buffered shape around a set study area. This was originally created for PCI Geomatica v9.1 but was last tested and working with no problems in PCI Geomatica v10.0 – Just copy the code below into a blank text file and edit as needed.
! Irregular_Polygon_Clip [bitmap_clip.eas]
! Ted MacKinnon – tmackinnon.com
! This simple script used with the MODEL command in PCI EASI
! will clip the unnecessary excess portions of an airphoto mosaic
! to an irregular buffered shape around the study area.
! The working file ‘working-file.pix’ has the existing
! mosaic image located in the first three channels,
! an existing irregular shaped polygon bitmap and
! three empty 8 bit channels.
! %%2 is the bitmap mask of the irregular shape
! %1, %2, %3 are the RGB existing image channels
! %4, %5, %6 will be the new modeled RGB image channels
! the RGB value of 255, 255, 255 will set the background to white
! Simply change the file name to use this script with a different
! file and ensure that the channels and segments are setup the same
! Set up and run the model
MODEL ON “working-file.pix” OVER dbiw
if %%2 = 1 then
%4 = %1;
%5 = %2;
%6 = %3;
%4 = 255;
%5 = 255;
%6 = 255;
! Export the resultant channels to a new file
FILI = “working-file.pix
FILO = “mosaic_clipped.tif
DBIC = 4,5,6
FTYPE = “TIF
FOPTIONS = “”