Recon for March 22nd - GPS Day

That is a great site for GPS. Do those marks have a good elevation on them? Due to a slip on the ice back in early January, I will not be able to go out and collect data this GPS day, but I have been digging through my archives and submitting previously collected data to OPUS DB. I found multiple observations on 6 bench marks so far. I can do my part with a bum knee.

The NGS has put together some pretty decent tools for determining which BM's to observe to get the most bang for the time spent. If you review the spreadsheets that are listed below the CONUS map for each State, they are listed by county, with a weighted ranking, based on whether the mark was leveled, mark stability, Geoid12A accuracies, and proximity to a road. The higher the rating (closest to 1.0), the more desirable to observe. Of course, this does not take into consideration the suitability for GPS observations or any local knowledge, like being prone to subsidence, etc... but it is still helpful in selecting marks to potentially observe on GPS Day or any time to help future versions of the hybrid geoid model:

http://www.ngs.noaa.gov/heightmod/GPSonBM.shtml

Here are some pictures for the points I have submitted. Nothing as grand as what Scott shared, but all good benchmarks in areas where the Geoid Model needs help.

Looks like a great plan Scott!

We did one on an old USGS bench mark along Route 299 in Shasta County last week. It is on about a 3" pipe sticking up a foot or so next to the old highway (now a gravel road). It was on their list.

The other we will do tomorrow afternoon. It is near Route 49 near the El Dorado/Amador County line. It is an HPGN station near the west end of a bridge over the Consumnes River. It is on a side road about 500' east of 49.

The last recovery note is by some Jim Frame guy;-).