Screenshot of a County Bridge Picture Page


(Top Left) Rob Coop using Collector  in a vehicle (Top Right) Fields now show Max. Length along with pull down menus.  (Bottom)  Sufficiency Calculations and Classification output

How it Works: In a nutshell GPS works by using signals from satellites to triangulate your location on earth to a fixed point.   There are 24 satellites that have been strategically placed in orbit around the Earth to beam signals back down.   Each of these satellites has an atomic clock on board that is able to provide extremely fine grain information on when the signal leaves the satellite.   A GPS receiver on the ground receives these signals.  By knowing the starting time from the satellite and how fast the signal travels the device can determine how far the satellite is away.  By receiving multiple signals from multiple satellites the device can triangulate itself to a precise position.  GPS signals can not travel far through a solid object.   For this reason GPS is only good outdoors and  typically line of site is needed to each satellite.   Typically 4 satellites is the magic number to obtain an accurate signal.

Accuracy/More Advanced Details: 
A typical commercial GPS unit is able to obtain accuracies of between 5-10 meters with good satellite fixes.  A number of factors (interference in the ionosphere and troposphere, angle to satellite signals, variances in satellite orbits and clocks) can effect the accuracy of GPS receivers.   Many applications require more precise and detailed location information.   To obtain higher accuracy more advanced GPS receivers use a technology called differential GPS.   In differential GPS a stationary receiver (at a known, fixed location) is also receiving the GPS signal.   Any of the error factors that are affecting the signal received by the mobile GPS device are also detected at the stationary point.  A corrective factor can then be determined and sent to the mobile device to remove the error.   In advanced utilization of this technology accuracy to the sub-meter level can be obtained.   

Application Usage:
Applications of GPS coordinates are numerous.   Typically, this information can be used directly with GIS (Geographic Information Systems) to provide accurate mapping and location services.   GPS can be used to help locate difficult to find items in the field or verify that an inspector is at the correct bridge, light pole, or sign before entering information.

From steel to timber, from concrete to stone InspectTech's software is helping  inspect and manage assets of all types!