No audio available for this content. Figure 1: Utility access box installed over CORS reference mark Whitefish Pt A (NGS PID AA8050) at USCG lighthouse. (Photo: Jeff Olsen) GNSS users who appreciate ...
No audio available for this content. Back in the late 1980s, as project manager of the new adjustment of the North American Vertical Datum of 1988 (NAVD88), I worked with federal and state agencies to ...
Keystones aren’t the only stones indelible to Pennsylvania’s character. Limestone monuments marking each mile of the Mason-Dixon Line — a survey line dating back to the 1760s intended to resolve a ...
Some results have been hidden because they may be inaccessible to you
Show inaccessible results