Welcome! This is my portfolio blog site displaying the different types of data analysis and geospatial tools that I use as a Geospatial Analyst.
Please feel free to provide comments and feedback to working projects!
Remote sensing with Land Cover Classification
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LULC Classification and Ground Truthing
In this exercise, we are using imagery located at Pascagoula, MS, to digitize the land cover surrounding the area and classify it by land use and description.
In order to do this, I decided to use a land cover legend to digitize the different land types using a polygon feature class. The different land types were given different colors to differentiate the symbology of the land cover.
I then used 30 sample points called "truthing points" to test the accuracy of my land cover results. I simply dropped 30 points on my image and then exported them to google earth using a kmz tool. I then zoomed in on each sample point and viewed the google Earth Image in 3D to see fi my land cover was classified accurately or not. I then coded my results in my truthing feature class to identify which points were accurate and wh9icvh ones were not.
Close Up View Of one Sample Point
The final map below shows the sample points in accuracy in comparison to the classified Land Cover...
Today We Are Using Imagery and Street Data I am creating digitized test points in the city below to compare a dataset of streets to a more accurate, local dataset of city streets. We are doing this to calculate the horizonal accuracy of the streets, by dropping points on intersections that both datasets share in commonality. This is what my Test data looked like with the new streets data. I am comparing these streets to the ABQ local streets (which are extremely accurate) to compare this sample of USA streets to the real data or "accurate street data". The red points are the intersections in the city. As you can see, these points were scattered to all 4 quadrants of the city for unbias distribution. Yet there will still be some bias included in the data due to the user, me, picking the intersections and the points. I also was using very high resolution oblique imagery to make sure I was comparing my test data to the real center point of the intersection. There is bias ...
Isarithmic Mapping Today we are going to talk about Isarithmic Mapping! This type of mapping is a way to explain smooth or continuous phenomenon such as a heat map, weather, temperature or rainfall. There are two types of these kind of maps, Isopleth and Isometric . .. Isopleth Maps : These are made from perceptual poi nt data such as the population of an area or the rate of crime in an area. These maps should be normalized if using raw data and should come from averages, densities, and ways to standardize the data. Such as the number of Covid cases per every 10,000 people, rather than coloring polygons of counties based on the number of covid cases. Isometric Maps : These come from true point data, such as crime locations as points at a certain address or X and Y coordinate The two rainfall maps of Washington below are Isopleth maps as they are using perceptual data of areas regarding their average rainfall in the state of Washington. This data is already standardi...
Today We Are Going To Talk About Geometries! In Arc GIS, we can use Python scripting through ArcPy to read geometry data and write the data to text files, csv's, or other file types. This is extremely helpful when trying to draw geometries in applications and mapping systems. The Python script that I created in this coding example takes a shapefile containing rivers (polylines of rivers) over an area and copies the rivers from the shapefile to a text file. This is extremely useful because we can share this text file with another GIS analyst, geocode these XY points to another map, run queries to analyze the data, and copy the data to other formats for web applications, dashboards, etc... Sounds Simple Right? I promise you its not... Let's go over the following things we need to do to make this happen: import our modules and set up our workspace create a text file called rivers text file create a search cursor to iterate through our rivers shapefile write some of the metadat...
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