Nathan Berger Portfolio: Geographic Information Systems

 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 ...

 Spatial Data Quality... What is spatial accuracy? Why do we care? When you build maps, or work with any kind of job in which you are presenting data, you want to be accurate and precise. Accuracy is essentially the inverse of error, or lack of error in a dataset. In regards to GIS, we are primarily focused on spatial accuracy. This is the positional accuracy of your point data.  If you have an xyz coordinate, such as a crime was committed at this LAT and LON, or address, we want that location to be correct when reporting it. You don't want to present to your boss at a marketing firm that Sally bought your product at a certain store, but in reality it was another store located 5 miles away because your coordinate data or spatial accuracy was full of errors! Think about SWAT teams responding to an active shooter and they end up at the wrong school. Or even something more simple such as trying to drive to a certain location and your GPS takes you to the wrong place.  There ...

Hurricane Damage In New Jersey Check out my Story Map at... https://arcg.is/0bLuWn Today we are going to talk about how GIS can map hurricanes, plan for natural disasters, estimate damages from these storms using imagery collection and GIS analysis... THAT SOUNDS LIKE A LOT! Pretty cool right? Hurricane Sandy was tragic and the map below indicates the path that it took going North of Cuba into the Atlantic Ocean, and then veering northwest into New Jersey.  Using GIS we can map the actual timeline of a natural disaster or a hurricane for instance as we track the meteorological data of the storm. We can look at on what day and time, where the storm was at its strongest and when it was at its weakest,. This helps policy makers plan for future storms, as well as manage current ones navigating there way to out coastlines. In this example, we can see that the hurricane became a category 2 storm north of Cuba, and decreased as it transits the Atlantic Ocean before hitting landfall. We si...

  What is Coastal Flooding?  Why use GIS to determine damage to infrastructure? By using GIS and Remote sensing Applications, we can determine how much damage a specific area received in regards to natural disasters.  An example would be hurricanes, tornados, and even tsunamis. For this exercise, a coastal flooding analysis was calculated to show the before area and the aftermath of the Hurricane Sandy storm that plowed through New Jersey.  We were able to calculate using elevation data taken from LIDAR to determine changes in elevation. In the map below, the areas depicted in red are where massive elevation changes have occurred such as erosion or destruction after the storm. The areas in dark blue indicate sand accretion or building debris.  Insurance companies can use maps like these to determine how many claims they will be processing after a major hurricane. We can also determine the level of damage, and what areas were affected the most.  Lidar DEM - ...

  Crime Analysis in GIS Specifically using Esri software suite such as Arc GIS Pro to build crime heat maps to display significantly high areas of crime. This can be based on crime rates using population data or area data, or even using kernel density calculations to define local clusters of crime.   Different algorithms such as Moran's I can define grid like hot spot areas of significant crime at a 95% confidence interval, allowing you as a GIS analyst to inform your command staff at your local Police Department  the areas in which Patrol should focus their efforts.  Defining a Crime Rate This map below is an example of calculating crime rate of a specific type of crime (Burglaries) in a specific area (Washington D.C.) using a standardization of population. We are calculating the number of Burglaries per 1,000 Housing Units. We started out using SQL Expressions and Table joins to select Burglaries from our crime point data, then joining the census dat...

  Introduction to 3D Visualization in Arc GIS Pro Today I am going to show some screenshots of using 3D data visualization techniques to solve real world problems. Think of this blog post as more of an overview of viewing different ways to see data in 3D. We will be looking at some LIDAR and elevation data, however there will also be some cool visuals such as viewing buildings in 3D and doing Line of Sight analysis.  I enrolled in a few online training courses online at the Esri catalog website which is included with any Arc GIS Online subscription. From there you can register and take as many courses as you want to develop your GIS skill sets.  Introduction to 3D Data: In this course, you can view 3D data in multiple ways. This image shows how a GIS analyst can use LIDAR data to measure distances beneath a bridge, or even visualize a new bridge being built. We can measure the distance of the bridge, the height, etc… This image shows a TIN Scene View...