Air Traffic Control Map

CEEn 414 - Civil Engineering Applications of GIS

Air Traffic Control Flight Map

Overview

Air traffic controllers deal with many issues while safely navigating airplanes in and out of airports. One important factor they must deal with is terrain. For obvious reasons airplanes cannot fly too close to the ground surface as they fly over mountainous terrain, but they must also be high enough that they can clearly receive/send radio messages from/to the air traffic control tower.

In the past charts showing minimum flying altitudes within a zone around an airport have been created and then air traffic controllers must insure that planes are above the specified elevation for each zone as they fly into or out of an airport. The map below shows part of the zone definitions around the Salt Lake City airport.

These zones are created by identifying peaks and then establishing a "shelf" at an elevation at least 1000 feet above the peak in the surrounding area. One problem with these maps is that they represent a discontinuous function, or in other words as you cross one boundary into another the elevation may change by 1000 feet, but a plane will not immediately climb or drop 1000 feet instantaneously (at least we would not want to be on the plane that did!). We should be able to create a smooth transitioning map and with GIS (ESRI's Spatial Analysis tools or similar) this is much easier than it was 10-20-30 years ago when such maps were originally derived.

For this assignment I want you to calculate the percentage of "unusable" airspace around the SLC airport according to the above map (I have converted the map to a shape file of polygons already). You should do this by noting the highest elevation zone in your data is 15,000 feet (this will be the upper limit), and we will assume the airport to be at 4200 feet (this may not be exact but is probably within about 50 feet). After you have done this using the zones I would like to repeat it using the elevation grid that is part of the data and then determine the "safety factor" involved with using the discontinuous altitudes.

Data

You can download the following data by clicking here. Note: All data are in the UTM NAD 27 Projected coordinate system, but the attributes given in the shape file represent elevation in feet so be careful.

1. mvautm.shp            Shape file of polygons showing the minimum flying altitudes in to and out of SLC.
2. boundaryutm.shp    Shape file (single polygon) of the area of interest for the SLC airport analysis.
3. mva.jpg (jpgw)        Jpeg image file (same as shown above) that you can use for reference.

You will also need to go to the Seamless USGS Elevation web server (go through http://emrl.byu.edu/gsda) and download the 3-arc second SRTM data. This is not on by default, but if you get the 1-arcsecond data you will find that it is too big! (10X as much data). You will need to manage the coordinate system so that it overlays correctly.

Analysis Tips

There are many different ways to solve this problem and I don't want to make too many suggestions for fear of stifling your own creativity. Here are a few commands though that you will likely want to use (just because I list something here doesn't mean that you must use it).

Converting your vector features to rasters
Using Map Algebra in Single Output
Keep in mind that the elevation grid is in meters and the attribute in the mvautm polygons is in feet. Also the ground (x-y) units of both are meters.
Remember that you should only calculate for the region inside the boundary polygon, so you may want to consider using the Analysis mask to limit the raster results.
When considering the volume be aware of the cell size for your raster.
We have not used the Spatial Analyst's cut/fill functions, but you may find it useful for calculations.
You might consider using the Zonal Statistics functions to Sum areas/volumes.

Assignment

Determine the volume of airspace available between 15,000 feet and the ground elevation inside the boundary polygon.
Determine the volume of unusable airspace in the boundary polygon (the volume between the zone polygons and 4200 feet).
Also report the amount of unusable airspace as a percentage of available airspace.
Using the elevation grid compute a new grid which defines unusable airspace as anything lower than 1000 feet off the ground's surface.
Using this new grid (rather than the minimum elevation zones) determine the amount of unusable airspace within the boundary polygon and also report it as a percentage of the total available airspace.
Make a map and prepare other information to report your results.

For this assignment you should turn in a web page showing the results of your team analysis. I think it is a good idea for you to each have a copy of the work so that you know you know how to do it. You should include a final map of your analysis and any other computed/summarized information on the web page. I would also like you to list the steps (you can model if you would like) that you used to develop your answer and your overall impressions of the results.