About David B. Zilkoski
David B. Zilkoski has worked in the fields of geodesy and surveying for more than 40 years. He was employed by National Geodetic Survey (NGS) from 1974 to 2009. He served as NGS director from October 2005 to January 2009. During his career with NGS, he conducted applied GPS research to evaluate and develop guidelines for using new technology to generate geospatial products. Based on instrument testing, he developed and verified new specifications and procedures to estimate classically derived, as well as GPS-derived, orthometric heights.
Now retired from government service, as a consultant he provides technical guidance on GNSS surveys; computes crustal movement rates using GPS and leveling data; and leads training sessions on guidelines for estimating GPS-derived heights, procedures for performing leveling network adjustments, the use of ArcGIS for analyses of adjustment data and results, and the proper procedures to follow when estimating crustal movement rates using geodetic leveling data.
Posts by David B. Zilkoski
Understand the differences between the North American Vertical Datum of 1988 and the new 2022 Vertical Reference Datum My Survey Scene columns have focused on procedures and routines for establishing... Read more»
These columns have focused on procedures and routines for establishing GNSS-derived orthometric heights. There are many ways to analyze and investigate GNSS data and adjustment results. I have provided some basic... Read more»
Upcoming Survey Scene newsletters will carry additional columns in this series. Basic procedures and tools for determining valid published NAVD 88 GNSS-derived orthometric heights for constraints These columns have provided the reader... Read more»
Basic procedures and tools for determining valid NAVD 88 heights for constraints To date, the six parts of “Establishing Orthometric Heights Using GNSS” have provided the reader with basic concepts, routines and... Read more»
Basic procedures and tools for ensuring GNSS-derived orthometric heights meet the project’s desired accuracy To date, this series of columns has addressed the following topics: basic concepts of GNSS-derived heights, National... Read more»
Basic procedures and tools for ensuring GNNS-derived orthometric heights meet the project’s desired accuracy
In the latest installment of our ongoing series, the focus switches from GNSS-derived ellipsoid heights to procedures and tools for ensuring GNNS-derived orthometric heights meet the project's desired accuracy. Read more»
Part 1 of this series appeared in the June Survey Scene newsletter, Part 2 appeared in the August newsletter, and Part 3 appeared in the October newsletter. Upcoming Survey Scene newsletters will carry additional... Read more»
Part 3 describes the differences between a scientific gravimetric geoid model and a hybrid geoid model, and why it is important to use both geoid models in your analysis. Read more»