Trimble Mapping & GIS

GPS Network Services

The CSDS RTN is California’s Leading GNSS Real-Time Network



What is the CSDS RTN?

The California Surveying and Drafting Supply Real-Time Network (CSDS RTN) is a dynamic GNSS Real-Time Kinematic network that provides more reliability, more coverage, and more accuracy than traditional single-base networks. The CSDS RTN provides RTK & GLONASS corrections to your equipment in the field, enabling you to achieve up to 1 centimeter accuracy. With no need for a station or rover radio, CSDS RTN users are able to reduce their hardware costs by up to 50% while achieving the same or better level of accuracy in their precision surveying & mapping applications.

How does the CSDS RTN work?

Each rover is equipped with a cellular internet connection an applicable data plan that connects to the CSVSN’s Virtual Reference System to acquire its GNSS correction signal. On the network side, the CSDS RTN utilizes a fully redundant server farm with Trimble Integrity Manager software that monitors 34 Reference Stations across California. This helps ensure accuracy and availability regardless of power outages, loss of reference stations, reference station movement due to earthquakes, etc. With the network being fully redundant and constantly monitored, it ensures you won’t lose signal when you need it most.

What areas does the CSDS RTN cover?

The CSDS RTN is available from Redding to Bakersfield (see coverage map). Currently, the available coverage area is 93,000 square miles, making the CSDS RTN California’s largest GNSS network.

What products does the CSDS RTN work with?

The CSDS RTN works with virtually all major surveying and GIS/GPS products.

How can I utilize the CSDS RTN?

CSDS RTN subscriptions are sold by California Surveying & Drafting Supply. Complete our online form to request a free trial subscription or more information. You may also contact your local CSDS Surveying or Mapping sales representative.

Coverage MapPricingNetwork Updates



One Time Setup Fee of $250

  • The One Time Setup Fee covers
    • A license for the user to access the system
    • Initial configuration of user’s equipment
    • Initial User System Orientation

Monthly Access Fee

  • $500 per month
    • Trimble Users receive a 20% Discount ($100 per user) Monthly fee – $400 per user
    • Multiple User Discount (3 or more users) as low as $320 per user






Northern California

License & Set-Up



Southern California




Multi-User Discount* (3 or more users)
*Contact your CSDS rep regarding multi-user discounts.
**Email for details regarding centimeter level accuracy


CSDS RTN Bulletin: Consolidated Subnets – A Single Network Solution (June 19, 2020)

As our CSDS High-Precision Realtime GNSS Network (RTN) grew throughout Northern California over the past 15 years, and because our state is known for its seismic activity caused by multiple fault lines (moving in different directions), we had split our Northern California RTN into two separate subnets: one Coastal network and one Valley network. This split allowed us to avoid the overall errors caused by high velocities between major tectonic plates. If not careful or constantly adjusted, the amount of tectonic drift in California would exceed the capabilities of any RTN software that relied on dynamically adjusting positions of rapidly moving, interdependent baselines.

Today our CSDS RTN team is excited to let you know that we have implemented new technologies and created new mountpoints that eliminate the need for multiple subnets.

The Technology Behind the Scenes

The new mountpoints connect to our already robust (and now Ed CSDS RTNconsolidated) single network. This means that there is no need to connect to a specific subnet based on your project location. The individual subnets will continue in place until December 31st 2020.

The latest format takes advantage of a few new technologies: Code Bias Calibration, Dynamic Station Coordinates and RTX Signal Processing.

Code Bias Calibration: With Code Bias Calibration, we send daily 24 hour observation data files to a Code Bias Calibration Service for each of our stations.  The service uses these files to calculate a station’s position using a 24 hour data set, and results are then sent back to our server to be used in the Dynamic Station Coordinates service.

Dynamic Station Coordinates: Once the new calculated ED - CSDS RTNpositions for the stations are received from the Code Bias Calibration Service, our server then calculates the difference between the the newly processed observations and the current position of each node in the network.  The server then takes this offset value and applies it to the positional information sent to the end user in the field. This adjusted positional information removes the occasional repeatability error we might have experienced on a single network of its size that was caused by the major plate velocities (movement) over such a large, linear area.

RTX Code Processing: With RTX Code Processing we process the positions of our stations over our entire network using satellite-based corrections.  This is a switch from determining the coordinates of our stations using baseline processing between the stations.  With RTX Code Processing, if there is an error in the coordinates of the station, that error is confined to the station itself.  Whereas with baseline processing, that same error would be pushed into the entire network solution given to our end users throughout the network.

CSDS Single RTN Network Details

Network address & port: Mountpoints are:


(or:, non-DNS)

Port: 5003




Site Calibrations & Ground Control Checks

With our continued focus on improving the convenience, up-time, precision and repeatability of the CSDS RTN, we remind RTN users to always utilize best GNSS field practices. All projects should contain control points (a minimum of 3 horizontal and 4 vertical – around the entire perimeter of the project) that can be checked and/or calibrated to, if necessary. Regardless of the stated precision of any RTN, significant seismic events or the need for an overall network adjustment can alter the positions of the reference stations in the network. Local project control, site calibrations and daily control checks will ensure that you are achieving acceptable precision and accuracy on your individual projects. Click on the following link for more information on the importance of GNSS Site Calibrations.

If you have any questions about our CSDS RTN or the technology mentioned above, please feel free to contact us at:

We thank you for being a loyal CSDS RTN Customer,

Ed Morrison, CSDS RTN Network Administrator

CSDS RTN Adjustment as of November 20, 2019

  • With our RTN spanning multiple tectonic plates in Northern California (that move in different directions at varying velocities), CSDS performs occasional adjustments to our RTN network in order to address any consequent movement of our reference stations.
  • This is to advise you that the current IP address you are using ( will reflect our upcoming, new adjustment.
  • The current (previous adjustment) correction source will be moved to a new IP address:
  • The correction source that is currently broadcasting on will no longer be available.
  • Your current username and password settings will give you access to the new and previous positional information.  If you need help with this please call CSDS at 833-SOS-CSDS (833-767-2737) and ask for Support.
  • We’ve also included some reminders and tips below that will allow you to achieve the highest precision and accuracy prior to and after this adjustment.

Be sure that you have control available to check and, if necessary, recalibrate to after this upcoming adjustment.

Maintaining Accuracy

Please ensure your crews are using the correct mountpoint for the subnet they are working in.  If they choose one of the Coastal mountpoints but they are working in the Valley subnet and vice-versa, they can see 2-3 tenths in error on the positions they are receiving.  If you are concerned about this as having occurred, you can: Review Job Settings > Ntrip Data Source.  The Ntrip sources that you have connected to will be listed there.

Be sure you have control available to check and, if necessary, recalibrate to after our adjustment.

Correct Mountpoints

When connecting to the new correction source servers ( you will notice a change in the mountpoints you are connecting to.  The new mountpoints will be:

  • CSDS_Coastal_CMRp(11242017)
  • CSDS_Coastal_CMRx(11242017)
  • CSDS_Coastal_RTCM31(11242017)
  • CSDS_Valley_CMRp(11242017)
  • CSDS_Valley_CMRx(11242017)
  • CSDS_Valley_RTCM31(11242017)

The existing mountpoints will be available on the old correction source server (

  • CSDS_Coastal_CMRp(04022016)
  • CSDS_Coastal_CMRx(04022016)
  • CSDS_Coastal_RTCM31(04022016)
  • CSDS_Valley_CMRp(04022016)
  • CSDS_Valley_CMRx(04022016)
  • CSDS_Valley_RTCM31(04022016)

*Leica Users – For those of you that are using the custom Leica mountpoints, those will be available to you on either system.  Use the IP address you want to connect to on the previously established 5010 port.

If you will be using both correction sources, understand that there will be consequences for choosing the wrong source for the job you are working on.  There will be coordinate differences and CSDS will not be liable for anyone performing work using the wrong source.  Control using the current reference frame must be established or available in order to calibrate back onto existing projects once our adjustment has been performed. All jobs where you are using the current positions will need a site calibration once the adjustment is in place.

CSDS RTN Network

For the best results, always use best practices

As always, proper survey practices are required when using the RTN. All jobs need to have a site calibration performed.  This ensures that control and coordinates are relative to your job site.  In addition to site calibrations, checks should be performed before starting and ending your survey each day.  If you want to use the new, more accurate correction source for your current job, you will need to perform a site calibration. More information on Site Calibrations:

Site Calibration Workflow
The Importance of a GNSS Site Calibration

If you have any questions, please direct them to your CSDS Sales Representative or contact our Support Department at 833-SOS-CSDS (833-767-2737).

We believe you will be very satisfied with the precisions of the split networks and updated adjustment to the CSDS RTN’s reference frame.

Ed Morrison
System Administrator, CSDS RTN


To request a trial subscription, or for more information, please complete and submit the form below. CSDS offers California-based businesses a 5-day free trial subscription to the CSDS RTN.

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