Road and Aviation Noise

While helping out someone that was looking for fatal accident data, I ran across a cool map service hosted by the US DOT Bureau of Transportation Statistics.  Looking at the REST endpoint for their map services, I found the National Transportation Noise Map.  The service description reads:

The National Transportation Noise Map is developed using a 24-hr equivalent sound level (LEQ, denoted by LAeq) noise metric. The results are A-weighted noise levels that represent the approximate average noise energy due to transportation noise sources over the 24 hour period at the defined receptors. This map includes simplified noise modeling and is intended for the tracking of trends, it should not be used to evaluate noise levels in individual locations and/or at specific times. https://maps.bts.dot.gov/noise/

If you click on the link in the description, it will take you to a document that outlines how the noise levels were collected and processed.  A few points about the data:

  • It is a simplified noise model to track trends
  • Flight operations are averaged into a single average annual day
  • Military operations were not included unless they were at a joint-use or commercial airport
  • Helicopter operations were not included
  • Flight track info was available for some airports for the modeling, and for the ones that did not have any flight track info, a straight-in and out procedure was modeled
  • For the road noise model, average annual daily traffic values were used in conjunction with vehicle types and speed, distributed evenly across 24 hours
  • The noise level cutoff of 35 db(A) was used

Adding the image service to ArcMap displayed this in the LA basin area:

noise1

I then changed the color ramp so high noise levels were red and low noise levels were blue.

noise2

Pretty cool … unless you live near LAX!

Extracting MORE Features from Map Services

Back in August 2015 I posted information about how you can extract features from a map service.  Since then, I have had many contact me about modifying the code so it can extract features beyond the record limit set in the map service.  So today I decided to work on one that does!

To test the script, I headed over to the map services provided by the State of California GIS.  Specifically, the one for wildfires:

http://services.gis.ca.gov/arcgis/rest/services/Environment/Wildfires/MapServer

When you scroll down a quick look will reveal that there is a maximum record count of 1000:

extractpt2-1

Continue reading

Bring LARIAC5 Early Access Imagery into ArcGIS Desktop

If your organization participates in LARIAC, then you probably know that right now you have Early Access to the 2017 imagery (both orthos and obliques) in Pictometry’s online CONNECTExplorer application.  Keep in mind the Early Access imagery still has work to be done on it, but at least you can take a look at the new stuff while they are working on it.

One thing you can do is bring some of the ortho imagery into your ArcGIS Desktop environment.  Here are the simple steps to do so:

  1. Login to ConnectExplorer and zoom to the area you are interested in.  Make sure to set the imagery date to “Early Access”.
  2. Next, set your Export Image preferences to output a GeoTIFF and turn off scale image, north pointer, and image date if you want.  You do not need a world file for a GeoTIFF.

    lariacortho1

  3. Next, bring up the ortho view of the area you want.  Make sure to zoom in quite a bit to get the higher resolution.

    lariacortho2

  4. In the lower-right corner, click on the export icon and select Export Entire Image.

    lariacortho3

  5. Now bring the GeoTIFF into ArcGIS Desktop.  Here I have the new 2017 ortho displayed on top of the 2014 ortho.

    lariacortho4

  6. Your image might look a little choppy.  To fix that, open the layer properties, select the Display tab, and change the “Resample during display” setting to “Bilinear Interpolation”.  The “Nearest Neighbor” setting will make your image too choppy looking.  Bilinear does a great job smoothing it out.

The GeoTIFF images are actually using geographic coordinates (WGS84), but they reproject very well into State Plane.

This is a very quick way to bring in the new 2017 Early Access imagery into your maps if you need to.  As the imagery is cleaned up and worked on to create preliminary images, there will be map services setup for you to consume in your applications.  But for now, you can use these steps.  Enjoy!  -mike