NOAA Online Positioning User Service (OPUS)

OPUS products on these pages will be released with the modernized NSRS, and use version OPUS-S 5.2 (more details below). This includes OPUS Static functionality, submitting your Multi-Constellational Global Navigation Satellite System (GNSS) data and receiving high-accuracy coordinates. Shared solutions will be available during testing, but take care to read the notes about changes and limitations to this function. OPUS-Rapid Static will be deprecated when NGS modernizes the NSRS, so that option is unavailable for testing. Additionally, OPUS projects functionality will not be available until the release of OPUS 6.0, anticipated to occur after the modernized NSRS has been deployed. Read more in OPUS Planned Improvements.

OPUS products on these pages will be released with the modernized NSRS, and use version OPUS-S 5.2. This includes OPUS Static functionality, submitting your Multi-Constellational Global Navigation Satellite System (GNSS) data and receiving high-accuracy coordinates. This update introduces new time requirements to obtain a solution, now a 1-hour minimum observation period.

OPUS - Share and Shared solutions will be available during testing, but take care to read the notes about changes and limitations to this function during the beta testing and public comment period. OPUS-Rapid Static will be deprecated with the modernized NSRS and is unavailable for testing. Read more about improvements to OPUS-Static and OPUS-Share below.

What is OPUS?

NOAA's OPUS software is your gateway to the NSRS. It provides simple, free access to high-accuracy coordinates by leveraging the same advanced software used to maintain the NOAA CORS Network (NCN) and the nation's geodetic control.

As we have transitioned to a New NSRS, OPUS has evolved to support multi-GNSS data, ensuring your projects remain aligned with the latest terrestrial reference frames.

To use OPUS, simply upload a GNSS data file (collected with a dual-frequency, survey-grade GNSS receiver) to the OPUS upload page. OPUS will accept RINEX observation files that are 1 to 48 hours in length. Your computed NSRS position will be emailed to you. If you choose, your solution can also be shared on the NGS website, if your observation is greater then 4 hours then you may choose to share your NGS to be published.

Helpful resources:

• Observer Field Log for GNSS Surveys

As of 2026, NOAA's National Geodetic Survey (NGS) has modernized to OPUS 5.2, replacing legacy systems with a multi-constellation, high-precision framework. This update introduces minimal changes to the time requirements to obtain a solution, now a 1-hour minimum observation requirement.

Key Modernization Updates in OPUS-S 5.2

• 1-Hour Minimum Occupation: All standard OPUS submissions now require a minimum occupation of 1 hour. This change ensures sufficient satellite geometry and data density for the high-accuracy requirements of the modernized system.
• New Error Estimates: The legacy peak-to-peak error has been changed to standard deviations from the least squares adjustment of baselines.
• M-PAGES Processing Engine: The legacy PAGES software has been replaced by M-PAGES, a multi-GNSS engine capable of processing signals from GPS, GLONASS, Galileo, BeiDou, and QZSS.
• Hub-and-Spoke Architecture: Processing now utilizes a "hub-and-spoke" style where your observation (the hub) is simultaneously processed (session processing) against stations within the NCN, (the spokes) using a single-difference phase approach.
• New 2022 Terrestial Reference Frames: OPUS now provides coordinates in the new North America (NATRF2022), Pacific (PATRF2022), Caribbean (CATRF2022), and Mariana (MATRF2022) Terrestrial Reference Frames or in the International Terrestrial Reference Frame (ITRF2020).
• Epoch-Based Coordinates: Latitude, longitude and height are now provided at a specific Reference Epoch (2020.0) of the new Reference Frames and at the Survey Epoch (the actual date of your observation), relative ITRF2020.
• Common Time Reference: To synchronize multi-constellation data from GPS, GLONASS, Galileo, and BeiDou, OPUS uses GPS Time as the primary internal time scale, ensuring all "hub-and-spoke" baselines are aligned to a single, nanosecond-accurate temporal reference.
• New Vertical Datum: Orthometric heights are now referenced to the North American-Pacific Geopotential Datum of 2022 (NAPGD2022) based on GEOID2022.
• New SPCS Projections and Zones: Projected coordinates will be provided by the State Plane Coordinate System (SPCS2022) using the lowest distortion zone by default.
• Deprecation of Extended Solution Format: The extended solution, providing additional detail and information on the base stations used and solution statistics, has been removed.
• Depreciation of the US Survey Foot: Due to the depreciation of US survey foot, all solutions using imperial units are provided in international feet.

 

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?

To use OPUS, simply follow these 5 steps:

1. Upload your GNSS receiver data file

Data files must meet the following requirements:

• Observables for both carrier phase and pseudorange
• Observables for two or more frequencies, for example GPS L1 and L2
• Include static data only
• Various file size limits are enforced.
  • OPUS uses only 30 second epochs.
    However, your file can include epoch intervals of 1, 2, 3, 5, 10, 15, or 30 seconds.
  • OPUS static uses between 1 and 48 hours of data, but
    your file cannot cross UTC midnight more than once.
If the upload form times out, consider reducing your data file size by zipping, thinning, or trimming it using vendor software.

Accepted data formats include:

• RINEX 3
• RINEX 2
• Compressed UNIX, gzip, pkzip, and Hatanaka formats.
  If you compress multiple data files into one, all must share one antenna type and height

2. Select your antenna type

To find the correct antenna type, browse antenna calibrations. Correctly selecting your antenna will help OPUS apply the appropriate antenna calibration model to counter the unique measurement biases inherent in each antenna's design. Choosing an incorrect antenna may result in a height error as large as 80 cm and a horizontal error up to 1 cm.

3. Enter your ARP height

Enter the vertical height (in meters) of your Antenna Reference Point (ARP) above the mark. See antenna calibration for a drawing of the ARP & NRP for your antenna.

4. Enter your email address

Your OPUS solution will be sent to this address when processing is complete. All steps have been completed and you may upload your solution unless additional processing is required.

5. Select Additional options

or first use the below to customize your solution content or format:
constellations allowed	OPUS uses selected Global Navigation Satellite System (GNSS) constellations,   if they are available in both your data file AND files from suitable base stations near you. Note, older bases may not yet be configured to record newer constellations.
	code : Name	Sponsor	availability from operational NCN (July 2023)
	G : GPS	U.S.A.	100%
	R : GLONASS	Russia	≃ 88%
	E : Galileo	E.U.	≃ 47%
	C : BeiDou	China	≃ 01%
	J : QZSS	Japan	< 01% (E. Asia & Oceania)
	Each satellite provides additional data to help solve for your position, especially useful for files of shorter duration, or collected in areas with limited satellite visibility.   You can force OPUS to exclude any constellation, either by unselecting it, or removing those records from your data file. You can allow OPUS to try to include any constellation by selecting it and if it is contained in your RINEX file. If OPUS still chooses GPS-only, you can force the use of GNSS base stations via the option below.
base stations	Tie your solutions to your favorite bases, or exclude any you consider suspect.
	Identify any CORS you wish to explicitly 'Use' or 'Exclude' from your solution using the arrow buttons. Station IDs use 9-character format.  Find CORS IDs Use with caution, as this overrides some base station suitability testing.
formats	choose either the standard one-page or the standard and JSON versions, described below.
state plane	coordinate system (SPCS) zone, allows you choose an adjacent or overlapping zone.
share my solution	prepare your data, plus photos and mark description, to be shared publicly.

after choosing your options, select

 

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How does OPUS processing work?

Processing Software

NGS's M-PAGES software is used to process all data from your submitted file alongside data from CORS's with well-known coordinates. The positions of the CORS's are constrained to their NGS coordinate function values at your data epoch. Code and carrier-phase measurements from all stations are processed in a simultaneous multi-station least squares adjustment, yielding coordinates which are tied to the NSRS through the constrained CORS's.

OPUS CORS Selection Process

The internal NGS CORS Selection process identifies the optimal CORS for a specific location and date by evaluating nearby candidate stations against a strict, multi-variable grading system. It first queries a database to find proximate stations, then fetches historical coordinate quality metrics (horizontal and vertical stability) alongside rolling 90-day data availability records. Each station is assigned a point-based score based on its distance to the target, coordinate stability, historical data reliability, and supported GNSS constellations, while strictly filtering out any stations with missing data on the requested day.

CORS Data Used

CORS data consists of continuous, survey-grade Multi-Global Navigation Satellite System (M-GNSS) tracking data from stations within the NCN. When you upload a static observation file, OPUS automatically selects the three most optimal CORS near your location. The positions of those CORS's are constrained to their NGS coordinate function values while estimating the coordinates of your station. If you need to pull the raw RINEX files, station logs, or daily coordinate data for your own independent post-processing, those products can be accessed directly from the NGS CORS data portal. If a specific set of CORS data is needed in RINEX format versions 2 or 3 it can be retrieved via the User Friendly CORS (UFCORS) website.

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OPUS Accuracy

 

How accurate is it?

Under normal conditions, most positions can be computed to within a few centimeters. For a specific solution, OPUS Static provides scaled formal error estimates which replace the historic “peak-to-peak” error. Note: Local multipath or adverse atmospheric conditions may also negatively impact your solution.

Static: Modern geodetic processing has transitioned from “peak-to-peak” ranges to a rigorous 1-sigma Standard Deviation (σ) approach.

How do the new error measures relate to peak-to-peak?

Error estimates from least squares adjustment of GNSS data are notoriously optimistic. To provide realistic errors to users, NGS has decided to scale the standard deviations by a factor of 4.0, so they are of similar magnitude to the traditional peak-to-peak error. These scaled-up errors are provided in your OPUS Solution.

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Improving your OPUS results:

 

Follow these guidelines to improve the quality of your OPUS solution:

• Observe longer: A longer session provides OPUS a better opportunity to accurately fix ambiguities and mitigate multipath error. The figure below shows the correlation between session duration and accuracy.
  • Stressler, B. (2022, August 11). Multi-GNSS Positioning with the New M-PAGES Software [Webinar]. NGS Webinar Series:
  
  
  
  

  Please Note: This figure is a result of a preliminary study under idealized conditions, the performance of OPUS may differ in your geographic location and real world conditions.

  • For a regional study using an earlier version of OPUS in real world conditions see, Gillins, D.T., Kerr, D., and Weaver, B. (2019). "Evaluation of the Online Positioning User Service for Processing Static GPS Surveys: OPUS-Projects, OPUS-S, OPUS-Net, and OPUS-RS," ASCE Journal of Surveying Engineering, 145(3): 05019002.
  
  
• Observe again: A second independent observation which yields a similar solution is an easy way to increase confidence in your results. To maximize independence between observations:
  • To share and publish data to NGS will eventually require two observations
  • Observe on a different day, at a different time of day


• Use Multi-GNSS Processing: Using multiple constellations (GPS, GLONASS, Galileo, BeiDou) increases satellite availability and strengthens geometry. To maximize signal reliability:
  • Higher Accuracy: More satellites lower the DOP and speed up "Fixed" solutions.
  • Redundancy: Prevents downtime in obstructed areas like woods or urban canyons.
  • Better Error Correction: Multiple frequencies help cancel out atmospheric delays.


• Requirement to include GPS in M-GNSS progressing: Include GPS signals into OPUS processing as every station in the NOAA CORS Network (NCN) consistently tracks them. Using GPS ensures seamless network processing and ensures your rover data will contain at least some common observables with all CORS.


• Wait a day before submitting your file: OPUS will use the best CORS and orbits available at the time you upload your data. While most CORS are archived within 30-minutes past the hour, some aren't available until the next day. If you process your data in less than 24 hours after collection, OPUS will use Ultra-Rapid orbits. Rapid orbits, available at 17:00 UTC the next day, will offer a slight improvement in your accuracy. Final orbits, available weeks later, offer only slight benefit to solutions in areas with usable CORS nearby.

What does a quality solution look like?

The most accurate OPUS solutions have the following characteristics:

• Orbits used are precise or rapid
• Over 90% of observations are used
• Over 50% of ambiguities are fixed
• The correct antenna type and ARP height are entered
• Overall RMS is less than 3 cm

Please note: OPUS may perform poorly or fail during periods of high ionospheric disturbance or during the passage of a strong weather front. In general, it is best to avoid collecting GNSS data during these events. To avoid collecting data during a geomagnetic storm, see NOAA's Space Weather Prediction Center, which issues geomagnetic storm alerts.

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Solution Formats

Two solution formats are provided from OPUS-S:

• Standard (ASCII Text): a sample standard solution is provided as ascii text in the solution email.
• Standard (JSON): the emailed solution is also provided in a json attachment.



Reminder: The extended output was deprecated in OPUS-S 5.2. Previous versions of OPUS provided an optional solution with more detail. This is no longer provided as standard OPUS 5.2 solution provides additional detail.

NGS OPUS SOLUTION REPORT ======================== All computed coordinate accuracies are listed as 1-sigma RMS values. For additional information: https://www.ngs.noaa.gov/OPUS/about.jsp#accuracy OPUS DISCLAIMER Warning text. Error and warning messages are appended here.
GENERAL INFO
RINEX File:RINEX File Your data file name, in RINEX format	1lsu322a.25o
RINEX Version:RINEX Version RINEX Data Format	3.0
User:User Your email address you use to receive the OPUS solution	your.email@domain.com
Date of Submission:Date of Submission The date and time you used OPUS	2026-06-10 08:02:45 UTC
Start of Observation:Start of Observation The first observation (Date, Time, and Julian Day) in your data file	2025-11-18 00:00:00 GPS (DOY 322)
End of Observation:End of Observation The last observation (Date, Time, and Julian Day) in your data file	2025-11-18 23:00:00 GPS (DOY 322)
Duration of Observation:Duration of Observation Length of observation in Hours:Minutes:Seconds	23:00:00 (hh:mm:ss)
PROCESSING INFO
Software:Software The software version used for processing.	M-PAGES 1.1.1 OPUS-S 5.2.0 250701
Ephemeris:Ephemeris The orbit file used for processing	igs23932.eph
Processing Mode:Processing Mode GNSS processing mode	Dual-frequency single-difference iono-free
Data Interval:Data Interval Observation data recording frequency	30.0 (s)
Elevation Angle Cutoff:Elevation Angle Cutoff Rejects satellite signals below a defined angle.	10.0 (deg)
GNSS Requested:GNSS Requested GNSS constellation(s) used for processing	GRE
EQUIPMENT INFO
Receiver Name:Receiver Name Receiver model name from manufacturer	TRIMBLE ALLOY
Antenna Name:Antenna Name Antenna model name from manufacturer	TRM115000.00 NONE
ARP Height:ARP Height Your selected antenna height in meters	2.0 (m)
Antenna Calibration File:Antenna Calibration File Antenna tuning file	ngs20.atx
BASELINE BASE STATIONS AND STATISTICSBASELINE BASE STATIONS AND STATISTICS PID and CORS ID of the stations used for simultaneous baseline adjustment.
PID / STATION ID LENGTH (km) RMS (m) GNSS AMB OBS DL8639 THHR00USA 87.510 0.0161 EGR 2.69 104512 DP8058 AMER00USA 107.264 0.0157 EGR 2.69 104709 DE8091 BVHS00USA 208.439 0.0157 EGR 2.66 105054
Variance Component: 0.86791	Variance Scale Factor: 4.0
ESTIMATED COORDINATESITRF2020 Your position: Earth-centered cartesian coordinates in the International Terrestrial Reference Frame (ITRF). Accuracies below are reported as standard deviations.	ITRF2020 (EPOCH: 2025.8808)
XX Fixed-frame coordinate, ITRF coordinate in ECEF	-113403.067 (m)
YY Fixed-frame coordinate, ITRF coordinate in ECEF	-5504359.561 (m)
ZZ Fixed-frame coordinate, ITRF coordinate in ECEF	3209403.152 (m)
Std. Dev. XStd. Dev. X Frame position standard deviation	0.0016 (m)
Std. Dev. YStd. Dev. Y Frame position standard deviation	0.0033 (m)
Std. Dev. ZStd. Dev. Z Frame position standard deviation	0.0026 (m)
LatLat Latitude	N 030 24 26.72857 (ddd mm ss.sssss)
LonLon Longitude	W 091 10 48.95080 (ddd mm ss.sssss)
EhtEht Ellipsoidal height	-8.611 (m)
Std. Dev. LatStd. Dev. Lat Latitude standard deviation	0.0027 (m)
Std. Dev. LonStd. Dev. Lon Longitude standard deviation	0.0016 (m)
Std. Dev. EhtStd. Dev. Eht Ellipsoidal height standard deviation	0.0031 (m)
ESTIMATED COORDINATESNATRF2022 Your position: Earth-centered cartesian coordinates in the National Spatial Reference System Terrestrial Reference Frames. Accuracies below are reported as standard deviations.	NATRF2022 (EPOCH: 2020.0000)
XX Fixed-frame coordinate in the NSRS Terrestrial Reference Frame in ECEF	-113402.995 (m)
YY Fixed-frame coordinate in the NSRS Terrestrial Reference Frame in ECEF	-5504359.565 (m)
ZZ Fixed-frame coordinate in the NSRS Terrestrial Reference Frame in ECEF	3209403.166 (m)
Std. Dev. XStd. Dev. X Frame position standard deviation	0.0016 (m)
Std. Dev. YStd. Dev. Y Frame position standard deviation	0.0033 (m)
Std. Dev. ZStd. Dev. Z Frame position standard deviation	0.0026 (m)
LatLat Latitude	N 030 24 26.72892 (ddd mm ss.sssss)
LonLon Longitude	W 091 10 48.94811 (ddd mm ss.sssss)
EhtEht Ellipsoidal height	-8.602 (m)
Std. Dev. LatStd. Dev. Lat Latitude standard deviation	0.0027 (m)
Std. Dev. LonStd. Dev. Lon Longitude standard deviation	0.0016 (m)
Std. Dev. EhtStd. Dev. Eht Ellipsoidal height standard deviation	0.0031 (m)
ESTIMATED HEIGHTNAPGD2022 Orthometric height datum, and geoid model used to compute it.	NAPGD2022 (EPOCH: 2020.0000)
Orthometric height (H)Orthometric height (H) The orthometric height	19.755 (m)
Std. Dev. HStd. Dev. H The orthometric height standard deviation	0.0241 (m)
Geoid height (N)Geoid height (N) Geoid undulation	-28.357 (m)
Std. Dev. NStd. Dev. N Geoid undulation standard deviation	0.0239 (m)
Geoid versionGeoid version Geoid model used to compute orthometric height	GEOID2022v1.0.0
ESTIMATED COORDINATESSPCS2022 Additional information on State Plane Coordinates (SPCS2022)	SPCS2022 (EPOCH: 2020.0000)
SPC ZoneSPC Zone SPCS2022 Zone ID	LA S-221002
Northing (N)Northing (N) Northings Projected Coordinate	235,705.504 (m), 773,312.05 (ft)
Easting (E)Easting (E) Eastings Projected Coordinate	640,321.985 (m), 2,100,793.98 (ft)
ConvergenceConvergence Projected meridian angular convergence from geographic meridian	0.15986944 (degree)
Point ScalePoint Scale Ellipsoidal distortion	0.999955189
Combined FactorCombined Factor Topographic and ellipsoidal distortion	0.999956540
Linear distortion (ppm)	-43.46
ESTIMATED COORDINATESUTM Additional information on UTM Coordinates	UTM (Zone 15)
Northing (N)Northing (N) Northings UTM Projected Coordinate	3365338.017 (m)
Easting (E)Easting (E) Eastings UTM Projected Coordinate	674802.467 (m)
ConvergenceConvergence UTM Projected meridian angular convergence from geographic meridian	0.92128611 (degree)
Point ScalePoint Scale Ellipsoidal distortion	0.999976968
Combined FactorCombined Factor Topographic and ellipsoidal distortion	0.999978319
US National Grid DesignatorUS National Grid Designator MGRS equivalent coordinate when projected into the NSRS, referred to as the U.S. National Grid designated position	15RXP7480265338
NEAREST NGS PUBLISHED CONTROL POINTNEAREST NGS PUBLISHED CONTROL POINT The nearest mark reported along with its position and approximate distance from your position.
BJ5321 LSU 1	N0302426.72855 W0911048.94779   0.0
DISCLAIMER: This position and the above vector components were computed without any knowledge by the National Geodetic Survey regarding the equipment or field operating procedures used.

 

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Error Messages

I got a warning message that the IGS Precise Orbit was not available at the time of processing, but the "rapid" was used. What does that mean?

We will not have the "final" IGS Precise orbit until the International GPS Service (IGS) completes a full week (Sunday through Saturday). This final precise orbit is the combination of seven analysis centers worldwide. It can take these analysis centers several days to upload the orbit to the IGS so the availability of a Sunday orbit can be 19 days. The IGS rapid orbit is used in the absence of the IGS precise orbit. However, this is not cause for alarm since the IGS rapid is nearly as "good" as the IGS precise. How does this relate to positions on the ground?

Since most OPUS baselines are less than several hundred kilometers, the differences between using the IGR (rapid orbit) and the IGS (precise orbit) is barely detectable if at all. Because of this, OPUS has discontinued this warning message (1/1/2004). For more information see IGS.
 
 

Some of my attempts to submit data generates a return email saying, "The observations to slip ratio is too low. There were an unusually high number of cycle slips in the data set. Aborting ..." (Code 1012). What does this mean, and how can I correct it?

This error message primarily indicates that your carrier phase data set contains too many cycle slips to assure an automated hands-off processing to obtain accurate results. The data may still be useful, but will require human intervention to efficiently resolve the cycle slips. Perhaps nearby radio interference or obstructions have caused an unusual amount of cycle slips.
 
 

I am trying to upload a RINEX file and I am getting a message that there are illegal characters in the file name -- what am I doing wrong?

The problem is probably not with the file name, but with the path name. OPUS is run on a UNIX machine, and it can only read path names that contain numbers, letters, the period, dash, and the underscore. If you move your file to another directory, it should be able to be uploaded.
 
 

My solution is not able to be submitted or shared. Why is this the case?

Often this is due to an GNSS observation not being long enough, OPUS-S 5.2 requires a minimum observation of 1-hour to generate a solution and a minimum of 4-hours to share your solution.
 
 

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FAQs - Static

I uploaded data. Why no response?

Solutions are usually sent within a few minutes, but it may take more than an hour to complete if traffic is heavy or your file is large. You will eventually receive either a solution or a failure message. Take care to enter your email address correctly and check your spam filters.
 
 

My nearest CORS weren't used. Why not?

OPUS tries to use your nearest CORS, but tests the integrity of each dataset, and will expand the search area until enough quality data are found. Also note some CORS data are not available until the following day. You may use OPUS options to force include or exclude specific CORS.
 
 

Is antenna required? If I select "NONE" will it use the L1 phase center?

While strongly recommended, if you leave the antenna as NONE your data will be processed with no offsets applied, resulting in a position a few centimeters above or below the L1 phase center. Ignoring your antenna's phase center variations will be interpreted as changes in tropo delays, causing errors in the tropo parameters which will degrade your solution.
 
 

What is the ARP height for Leica antenna model SR 399, with GRT44 tripod mount?

If you have this type of antenna mounting, the ARP height can be determined by using the following equation: Height of ARP (meters) = 0.350 + tape measurement (meters) "Tape Measurement" is the distance in meters from the bottom of the hook in the antenna mounting to the monument.
 
 

My Terrestrial Referencee Frame coordinates are missing. Why?

Sometimes OPUS uses CORS from outside the NGS network that have IGS global positions but no listed NATREF2022 coordinates. Your resulting positions will be just as accurate, but the Reference Frame coordinates values will not be listed. Additionally, positioning defined in NGS Terrestrial reference frames are limited to US Territory by default. You may override this behavior by specifying a processing frame at the time of solution submission. You should go to the NGS website and use NCAT (the NGS Coordinate Conversion and Transformation Tool) for more complex conversion. This modernized tool replaces HTDP for converting positions between global frames such as NATREF2022 reference frame.
 
 

contact OPUS
 

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Sharing your OPUS solution

Sharing your OPUS solution is a critical contribution to the stability and longevity of our nation’s spatial infrastructure. By making your data public, you help maintain the essential local ties between physical, passive geodetic control and the National Spatial Reference System (NSRS), ensuring that ground marks remain accurately anchored to the federal coordinate framework as the Earth’s crust shifts over time. These shared solutions were fundamental in building the Transformation Tool for the new NSRS, enabling the seamless conversion from legacy vertical datums to the new, gravity-based North American-Pacific Geopotential Datum of 2022 (NAPGD2022).

The Path to a Public Solution

To share your results, simply upload your GNSS data, verify your antenna type and ARP height, and select “Yes, Share” under the Options menu. To ensure the integrity of the public record, shared submissions must meet these rigorous standards:

• Observation Length: Your data file must represent a minimum of 4 hours of high-quality GNSS observation.
• Mark Integrity: The location must be a permanent mark of public interest — durable, stable, and situated with clear satellite visibility.
• Verification: Modernized standards now prioritize redundancy, often requiring two or more observations at a single location to ensure positional stability before it is added to a larger survey project.
• Documentation: You must provide a clear description and site photos to assist future users in recovering and utilizing the mark.

Reminder: Data submitted via OPUS Share during the Beta period will be used for testing purposes and will be deleted prior the official transition to the modernized NSRS.

Precision Requirements for Sharing

Publicly shared solutions are held to a higher standard of precision to ensure they serve as reliable references:

• Horizontal Error: ≤ 2.50 cm standard deviation for East and North coordinates
• Vertical Error: ≤ 4.00 cm standard deviation for Up coordinates

We welcome all submissions, feel free to contact our specialists at info.NGS.com

Helpful resources:

1. Preview the OPUS description form help file.
2. Access the Observer Field Log for GNSS Surveys
3. Tutorial: How to Submit an OPUS Share Observation
4. Lesson: GNSS Positioning: Survey Planning and Data Acquisition
5. Lesson: Foundations of Global Navigation Satellite Systems (GNSS)
6. Video: Best Practices for Minimizing Errors During GNSS Data Collection

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OPUS Planned Improvements

NGS continues to enhance the Online Positioning User Service (OPUS). We will be creating OPUS-6 a modernized replacement to OPUS-Projects. OPUS-6 is a cloud-native software suite currently in development with the intended use to allow for the processing, adjustment, and submitting of geodetic survey projects within the modernized National Spatial Reference System.

Please Note: OPUS 6 will not be available when the modernized NSRS is officially adopted. Additionally, January 13, 2027 is the cutoff date to submit GPS projects submissions through OPUS Projects.