Image: National Geodetic Survey

The differences between published Geoid18 and Geoid12B values in Southern Louisiana

April 1, 2020

My February 2020 column provided an analysis of the differences between the latest published hybrid Geoid18 values provided […]

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This article is tagged with David B. Zilkoski, GEOID12B, GEOID18, GEOID18 Gulf Coast, GPS data, GPS on Bench Marks, National Geodetic Survey, NGS, Southern Louisiana and posted in Opinions, Survey

Example of a Large Difference Between Geoid12B and Geoid18 in Western North Carolina (Screenshot: National Geodetic Survey)

How to use the NGS Beta GEOID18 web map

June 5, 2019

This column discusses the results of the National Geodetic Survey (NGS) beta hybrid Geoid18 model and the differences […]

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This article is tagged with David B. Zilkoski, GEOID12B, GEOID18, GPS on BMs program, hybrid geoid model, National Geodetic Survey, NGS and posted in Opinions, Survey

Image: National Geodetic Survey

NGS 2018 GPS on BMs program in support of NAPGD2022 — Part 8

August 1, 2018

My last two columns (NGS 2018 GPS on BMs program in support of NAPGD2022 — Part 6 and […]

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This article is tagged with David B. Zilkoski, GEOID12B, GEOID18, GPS on BMs program, NAPGD2022, National Geodetic Survey, NAVD 88, NGS 2018, OPUS and posted in Opinions, Survey

Figure 2 - Positive GPS on BMS Residuals Using Geoid16b_NAD model (note: rejections by geoid team have been removed).

Analyzing NGS’ GPS on benchmark dataset used to make GEOID12B — Part 9

October 5, 2016

These columns have focused on procedures and routines for establishing GNSS-derived orthometric heights. There are many ways to analyze […]

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This article is tagged with Dataset, GEOID12B, NGS, NGS Dataset, Survey Scene, surveying and posted in Opinions, Survey