Introduction
What is GIS? GIS stands for Geographic Information System as
it relates to mapping technology. Basically,
it is using computer software to analyze geographic data. Christopher Gold from the University of
Glamoragan wrote in an article What is
GIS and What is Not? that the most important concept to comprehend is scale
and geographic location. He said that GIS modeling is when the viewing of the
model changes the readers perspective, not where the model moves or rotates
like in CAD for example (Gold, 2006). The idea being that GIS is not just the
software but the relationship between the data and what the potential products
are. That just putting together a picture and calling it GIS is not the same
thing as provided a valuable graphically representation of spatial data that
serves to illustrate a particular point or direct the viewer into reaching the
desired conclusion of what the data is saying.
Open source systems are intertwined within the world of
unmanned operations. It is especially
evident for entrepreneurs and innovators within this field. Open source can be the bridge between
conception and reality. Where private
sector software can provide stable reliable interfaces and relate-able analysis
of GIS data, open source could bring new angles or ways to analyses the data
that have not yet been advocated for. Thus,
bringing about a future of conceptual ideas much faster by not having to wait
for software to be designed and licensed like in traditional software suites.
Using Qgis, an open source GIS software package, the Digital Surface Model (DSM) on the left was created. The process for creating this image with Qgis was very similar when using another paid software, called ArcMap, to create a similar rendering. On both applications, the data was loaded into the software either by directing the file path to the information or by using a "drag-and-drop" method. Again on both applications, the open source and proprietary, an extension was downloaded to to manipulate the original data to show elevation changes clearer using a function called hill-shade. The original image is shown to the right for comparison of what the hill-shade feature does to the image. Both of the above images where developed through the use of Qgis open source software. The two maps below show a side by side comparison of the final product from the two types of software that was used to create them. The first map was done using ArcMap, while the second was done using the free Qgis software.
One feature from Qgis is to assign and modify color bands to an image. To do this, I first navigated to where I had saved the data and opened the files, the data that had each individual bands saved as different images. Then, using the merge raster GUI, i assigned bands to the different individual layers to represent red as showing healthy vegetation. I did this primarily by hiding the green band and emphasizing the red and yellow bands. This false color stacking of a sample data set can be seen in the map below.
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