Illinois Height Modernization


In a nation-wide effort to gather and update state and national databases with accurate information about topographic changes in elevation, many states have participated in the push for better data by launching statewide height modernization initiatives.


With many states lacking sufficient elevation data due to lapses in monitoring and damaged or destroyed control markers, states like Illinois have recently made strides in updating their networks of survey markers to ensure changes in elevation can be measured and tracked for decades to come.


In addition to gathering richer, more complete data, federal agencies like NOAA are taking the opportunity to improve coordination and communication between states in an effort to boost regional collaboration around the country.


Let’s look closer at one state’s efforts to modernize a particularly disconnected measurement system using robust geodetic survey products as the foundation of their operation.


An overview of height modernization’s goals and objectives


While each state shares the same general goal of improving the quality of elevation data within their area, particular objectives depend on the specific needs of each state. Illinois began their height modernization project with three main goals in mind:


1.     Establish a datum-consistent vertical and horizontal statewide network of benchmarks.


2.     Create a high resolution Digital Elevation Model (DEM) of the earth’s surface using the new data found through an updated system of benchmarks.


3.     Establish an outlet for distributing the new data to agencies and other organizations.


When it comes to making this new data practical, the program aims to help improve the quality and efficiency of future engineering and land-use planning projects.


Illinois’ geography in particular puts it at a significant risk for flooding in some regions––a problem height modernization tackles by improving preparedness when incidents do occur.


Expanding the statewide benchmark network with robust survey monuments


One of the most important tasks of the project is expanding the network of benchmarks used to survey and track changes in height on the surface. As older benchmarks become damaged, destroyed, or lost over time, surveyors need a solution that can withstand many decades of exposure to natural conditions before requiring significant repairs or replacement.


Each of the benchmarks placed around the state correspond to a particular datum used to mark and measure the elevation level.  Before modernization, there were a variety of datums spread across the state with no standardized system to connect regions together. This resulted in a costly inefficiency, which is now being improved as older datums are replaced over time.


Berntsen’s Top Security Sleeve Monuments provide durable solution for surveyors


To ensure datums remain consistent and accurate, the project turned to Berntsen’s Top Security Sleeve Monuments, designed especially to resist natural conditions that can affect unprotected survey monuments.


These sectional rod monuments are built specifically for applications where natural phenomenon can cause unexpected shifts in stability, throwing off measurements and causing costly maintenance.


Budget considerations are a primary concern for most projects, both public and private. Berntsen’s Top Security Sleeve Monuments also give surveyors a cost effective solution when it comes to installation. Using a standard “grease gun” fixed with a specially-designed grease cartridge, rods can quickly be driven to refusal and fitted with the grease-filled Top Security Sleeve, to help reduce the effects of frost heave.


In total, 301 new geodetic benchmarks will contribute data to the National Spatial Reference System, adding Illinois to the list of states now modernizing to provide a safer, more cost effective future.


If you want to learn more about our selection of Sectional Rod Monuments, visit Berntsen’s Survey Monument product pages or request a catalog today.


Photo credit: Illinois State Geological Survey