SGU1: Information on the City of St George Community GPS Base

 Hello All,

Todd Jacobsen and I are excited to announce that SGU1 has been added to the NGS National CORS infrastructure!

This will have some immediate impacts on GPS Surveys in SW Utah:

          o SGU1 will shorten the baselines of all OPUS solutions in the area

          o This will allow more complete OPUS-RS coverage in the region

          o OPUS-RS should be much tighter than before

          o We (after 9-years) are going to adjust the broadcast position a few mm!

          o Static data will be available going forward and for the last 56 days (since JDay 066) from the NGS website


The current coordinates in use for RTK transmissions are:

 37 06 47.48102 N  113 34 13.02300 W  895.589 m NAD83, CORS96

After 60 days of NGS network computations, NGS has computed:

 37 06 47.48115 N 113 34 13.02321 W 895.565 M, NAD83, CORS96

The horizontal difference is 0.007 meters, elevation 0.024 meters.

It is our plan to wait 30 to 60 days and then change the base position for transmitted locations; to allow for user comments and suggestions.

Please drop us a note if you have any comments, we hope to make this change with ZERO side effects for ALL users.


The Future

Our remaining item for next fiscal year (2012-2013) is:

On the day of the radio change (late July – early August) Shane Aldridge (Rocky Mtn Transit Instruments), Ryan Atkinson (Monsen) and Mark Silver (Igage) will have picnic in St George, invite everyone over for lunch and make sure that everyone’s radios are good-to-go with the change. We will give you plenty of advanced notice!


Help Us Get The Word Out!

If you know of anyone who may be affected by these changes or who uses the St George base, please invite them to join this mail list. Clicking on the link below will get a simple sign-up form:

You can view past messages here:

If this message has found you in error, the link at the very bottom will remove your email address from future messages (really, it does work!)

City of St George Feedback

My experience tells me that the best base is one that someone else takes care of; please let the City of St George know that you appreciate this community resource.

If everyone who used SGU1 took a moment and wrote a short letter of appreciation to the city I am sure it will make it easier to allocate money for repairs, maintenance and connectivity in the future.


If you have any suggestions or comments please drop Todd ( ) or I ( ) a note.

Good survey and mapping to you all,

Mark Silver,
Igage Mapping Corporation
1545 S 1100 E STE 1
Salt Lake City UT 84105

801-412-0011 x16