California Real Time Network (CRTN) - Trimble Access Coordinate System

There is an update coming for the Coordinate System Database that will include a beta version of CRTN2025.

It does not appear to be downloadable from Trimble Field Systems yet.

It should be available with the next release of Access, which is due very shortly

@jimcox

I checked this, unless I am looking in the wrong place, I only see 2017 not 2025 

@mk93

Sorry, you are right. I did some checking. The website install is v112 of the CSD - latest Access version installs v113, 2025 is in v114 which is still to come.

(I've edited my previous post)

Since CRTN is aligned with the NSRS NAD83(2011), as long as your coordinate system is set to NAD83(2011) you can use the CRTN horizontal values as-is.  You'll only run into trouble if you mix the CRTN coordinates with values from a source that isn't at epoch 2025.00 or has been subjected to earthquake movement since it was positioned.

CRTN uses GEOID18, so mixing with coordinates derived from another geoid model can also cause conflicts.  But I think most of us probably use CRTN as a sole source of grid coordinates, so we're getting NAD83(2011) / NGVD88 right out of the box.

When I setup the coordinate system to NAD83(2011) the "Epoch 2010" was throwing me off. Are you saying what's shown below will align with coordinates the updated CRTN base station (Epoch 2025) will generate? 

Yes.  The only error source introduced by this setup that I can think of is that the geoid model will, in theory, be applied in the wrong place, but the difference between 2010 and 2025 coordinates is magnitudes smaller than the resolution of the geoid model, so that error is insignificant.

Unless Access is applying a transformation, the choice of realization and epoch is meaningless save for reporting purpose.  The projection parameter for the plane coordinate systems have not changed since their introduction in the 80's.  The same holds true for most processing and CAD software.  My personal preference is the to keep it simple and choose the barebones NAD83. I have seen occasions where a software does apply transformation without notice.  I like to choose how and when that takes place.

That being said, you still need to be aware of the realizations when tying into passive marks or older projects, then you will need to perform some type of transformation between system.

It does look like Access does a transformation when including RTX data.  So if that is in you plane then you would need the correct realization.

@john-putnam Thanks, I only switched to Trimble few months ago so still learning how Access works

Update: Trimble have released a new 2025.20 version of Access.

This version also includes v114 of Trimble's Coordinate System Database.

This includes beta versions of the NSRS coordinate systems.

If you have Coordinate System Manager you should be able get it via 'Check for updates'