November 15th 2016 - SLUG Meeting DiGISt

Minutes of the 30th Quarterly Salt Lake GIS Users Group (SLUG) meeting, held on November 15, 2016, from 11:30 am to 2:00 pm at the University of Utah’s Ray Olpin Student Union building.  There were about 110 in attendance.

This meeting’s lunch was sponsored by University of Utah DIGIT Lab. If you have any contacts that would be willing to “sponsor” a lunch by providing food/ drinks in exchange for giving a 5-minute plug about their company at the meeting, contact Tom Toronto, SLUG Board member.

Welcome and Introduction:

Phoebe McNeally, U of U Geography Dept

Phoebe welcomed everyone to the University of Utah for Geography Week.


Adrian Welsh, SLUG Board

·      The next SLUG meeting will be February 15th at the Doty Education Center (IMC) in Murray. Hope you will be able to attend!

·      We are always in need of presenters. If you would like to present, or suggest someone who you’d like to see present, please contact Neal Fraser, SLUG Board member.


Amenity, Accessibility, and Housing Values in Metropolitan USA: A Study of Salt Lake County, Utah

Han Li, U of U

Rapid growth from 2000-2010 drove significant increases in housing demand; using Salt Lake County as a case study area, this analysis examined the relationship between home values and the amenities in the nearby areas as well as accessibility as a function of various transportation modes.  The study also examined tax and socioeconomic data.  This regression analysis looked at several different municipalities in the County, and examined natural, modern, and historic amenities such as parks, education, and employment opportunities.  The study found a positive correlation between amenities and home prices.

Assessing Firefighter Safety Zones Using Lidar Remote Sensing

Mickey Campbell, U of U

In wildland firefighting, the crews always need to have a “safe zone” identified in case a rapid, emergency evacuation is required.  In many cases, this is an area that has already burned, which eliminates the fuel source and means that it cannot burn again.  Crews will establish a visual trigger point that tells them that when a fire hits a certain location, they need to evacuate.  In order to identify the most efficient escape route to reach the designated safe zone area, variables such as terrain, distance, and vegetation need to be taken into account.  This study modeled the differences in travel speed of a person on foot over various types of terrain and topography to calculate least cost routes using Lidar data to generate the cost surfaces.

Web-Based House Damage Wildfire System

Yingxie Li, U of U

This study considered the loss of primary structures in the urban/wildland interface, and examined ways that the communication could be improved of home loss notification between residents and emergency response personnel.  Maps are very helpful in this regard, and are aided by social media and other mobile device-compatible methods.  Dynamic and interactive interfaces with up-to-date information are very important.  There was also an interesting discussion of client- and server-side considerations.

Vector Tiles Lightning Talk

Joe Rhodes, Esri

Joe is a local government contract manager for the area, and as such has interacted with many SLUG members.  His demo was intended to show the advancements that vector basemaps have brought, such as faster rendering, smaller file size, and eliminating the need to cache.  This is currently in beta, but should be out of beta by early 2017, but will only be available to be published from Pro.  View Joe's Demonstration here.

Geography Humor Segment 

Neal Fraser, SLUG Board

Strangest Time Zones of the World: This eight minute YouTube video highlighted some of the funkiest, quirkiest, funniest time zone oddities in the world.  This elicited many laughs from the audience, especially when discussing oddities such as China using a single time zone for one of the largest countries in the world, which results in a big difference between clock time and solar time.

Homegrown Aerial Photography

Benjamin Clement, Carbon County

This presentation was about the aerial photography collection efforts that Carbon County is implementing.  This was a very useful talk that covered many of the potential pitfalls and lessons learned that they have experienced through this trial and error process of getting the program up and running.  Some of the important considerations are the time of day to fly, the time of year to collect the imagery, and wind speeds, as those can potentially blow the Cessna plane off course from the grid that it needs to fly.  The plane flies at 1,800’ altitude, and collects 4” photography with a 35 mm lens.  The grid lines are uploaded to a tablet for the pilot to follow, and are spaced approximately 1,200’ apart with a 530’ overlap buffer.  Benjamin said that they have made lots of expensive mistakes, but that the program is very promising and will deliver high quality data to the County.  He uses Software Correlator 3D from Simactive to process the photography, and ExifTool to remove image rotation.  One township’s worth of images takes approximately 30 hours to process, and the flight time to collect those images comes in around 3.5 hours.  It can take significantly longer if you need to reproject control points, and the Cessna costs $300/hour.  They also learned some lessons about which cameras can go in which aircraft.  The end product is a point cloud that is similar to Lidar.  One of the major benefits of this program is that the County can dictate the update cycle for their aerial imagery, and it can then be used for planning-level data.

Thank you to our presenters and our venue. If you have any ideas for a presentation or any other matter, please contact a SLUG board member.  And thanks for your interest and support!