Illinois Height Modernization Program

Every engineering project, and many land-use planning efforts, require accurate measurements of heights. Correspondingly, a datum-consistent vertical and horizontal statewide network of survey benchmarks is needed, along with a statewide high-resolution digital elevation model (DEM) of the earth's surface.

Unfortunately, Illinois currently falls far short of these goals and is ranked in the bottom ten states, regarding the quality of its elevation data. The National Geodetic Survey (NGS), part of the National Oceanic and Atmospheric Administration, provides funding to states through the federal Height Modernization program to improve the quality of elevation data using global positioning satellites (GPS) technology in conjunction with traditional leveling, gravity, and modern remote sensing.

Illinois became part of the NGS Height Modernization Program in 2008. Our project aims to partner with NGS, USGS, and other Illinois state agencies to upgrade the statewide network of survey benchmarks and develop a statewide high-resolution DEM data set. The initial project focus area for the Illinois Height Modernization Program (ILHMP) is northern Illinois, which extends from the Chicago metro area westward to the Mississippi River Valley.

ILHMP Project Goals

ILHMP project staff seek to establish:

• a datum-consistent vertical and horizontal statewide network of survey benchmarks, and
• a high-resolution DEM of the earth's surface based upon the updated network of survey benchmarks, and
• an outlet for distribution of elevation data. for Illinois

Year 1 activities have included:

• development of project web resources
• development of a design for benchmarks installed by the program
• development of outreach materials, including a ILHMP Flyer: Height Modernization for Illinois
• participation in the new Great Lakes Region Height Modernization Consortium (GLRHMC), including
  Illinois, Indiana, Iowa, Michigan, Minnesota, Ohio, Pennsylvania, and Wisconsin
• performance of outreach activities at state and national conferences,
• an information survey about existing digital elevation data collections,
• an information survey about existing benchmarks and reference datums,
• establishing data sharing agreements to archive and distribute elevation data for several Illinois counties,
• receiving and archiving LiDAR and derivative data for 7 Illinois Counties,
• releasing an open contract for geodetic leveling for about 40 miles in northern Illinois,
• granting the contract for geodetic leveling to a group led by Patrick Engineering and including Berns, Clancy & Associates,
• geodetic leveling work contracted for geodetic leveling and installation of 22 monuments in Winnebago and DuPage Counties, and
• consulting with the US Army Corps of Engineers on coordinating the level line with water level gages that need NAVD88 heights.

Year 2 activities will commence in September of 2009; activities will include, but are not limited to:

• expansion of project web resources to provide data access for Boone and Winnebago counties
• development of outreach materials, including an ILHMP project poster
• hosting a Real Time Network (RTN) Workshop for the GLRHMC on November 10, 2009 in Rockford, Illinois

  RTN Workshop Flyer

  RTN Workshop Agenda

  B. Herzog, ISGS: Welcome, ILHMP Introduction

  R. Shields, NGS: National Height Modernization Update

  C. Pearson, NGS: Introduction to NGS CORS and OPUS

  B. Henning, NGS: Background on Real Time Positioning

  B. Henning, NGS: NGS and Real Time Positioning

• performance of outreach activities at state and national conferences, and
• releasing an open contract for additional geodetic leveling in northern Illinois.