California Spring Adjustment - May 16, 2022

It is once again time for a broadcast coordinate update in California.  The new broadcast coordinates will be published as of Monday morning May 16, 2022 at 5:00 AM ET and will ONLY effect California.

Why are we doing this adjustment?

California offers a unique set of challenges for RTK users.  A vast majority of the stations in California have significant positional velocities, which in short means they move.  On average the position of the stations in California moves between 30 and 50 mm-a-year, and in some areas even more.  The average shift over the entire network for this adjustment was approximately 16 mm.  

Without our semi-annual adjustment of station coordinates in California, you would quickly see measurable coordinate differences as you moved throughout the state.  As the velocities of the stations vary from location to location, this can cause issues not only as you cross the plate boundary, but also in the area of influence of the plates themselves.  In California's case, this means pretty much anywhere in the population centers of the state.

To get a better understanding of why we are doing this adjustment, please watch our latest SmartNet North American Adjustment Webinar - LINK.

What does this adjustment mean to me?

In very simple terms it means the broadcast position of the base is going to move approx. 20 mm.  This is a relative small change that you may or may not realize in the field, however as more time passes between adjustments, the larger the immediate impact would be.  By adjusting twice a year we mitigate the shift from adjustment to adjustment.

What reference frame and epoch are we moving to?

We will still be in the NAD83(NA2011)(MYCS2) reference frame to stay consistent with the NSRS and we are moving to a 2022.250 epoch.

How can I get back to my old coordinates?

With the introduction of Spider 7.1 in 2017, we introduced Multiple Reference Frame (MRF) Mountpoints.  These mountpoints allow you to access the Common or Last Coordinate Class that was published.  You can find more information on how to use these by watching the video below.

You can also perform your own local transformation, localization or calibration.  For more information about using this technique, please click here - LINK.

How do I see the current coordinates and superseded coordinates?

All current, common, last and superseded coordinates are available on the SmartNet User Portal.  You can find a station's information by using the "Site Information Search" tool, then you can see the current broadcast and processing coordinate, as well as find a button that will allow you to view all the coordinates available via an MRF mountpoint and superseded positions as well.

Once the new adjustment is published on May 16, we will also update the site database with the new NAD83(NA2011)(MYCS2) Epoch 2022.250 coordinates.

For more information on using the "Site Information Search" tool, we encourage you to watch this short video - LINK.

How do I get support to better understand what this adjustment means?