If you already own a GNSS receiver, you may not need to buy another one to start using a CORS network. So, what do you need to connect your GNSS receiver to CORS in Nigeria? Depending on your equipment, you may only need an internet connection, access to a CORS service and the correct NTRIP settings.

But how do you know if your GNSS receiver is compatible? Do you need a base receiver? Where does the SIM card go? And how do you obtain the connection details?

These are important questions to answer before attempting to connect your equipment to a CORS network.

In our previous article, CORS in Nigeria: How CORS Is Changing GNSS and RTK Surveying, we explained how Continuously Operating Reference Stations (CORS) are changing GNSS and RTK surveying.

This article takes things further by explaining what you need, how the connection works, and how you can get started with OTIC CORS.

1. Does Your GNSS Receiver Support Network RTK?

This is the first thing to establish. Not every GNSS receiver can connect directly to a CORS network. Your receiver must support Network RTK and an NTRIP connection to receive correction data over the internet.

NTRIP (Networked Transport of RTCM via Internet Protocol) is the communication protocol used to transmit GNSS correction data from a CORS network to your rover.

Before subscribing to a CORS service, check your receiver's specifications or ask your equipment supplier whether it supports NTRIP and network RTK.

2. Do you need a base receiver to use CORS?

No. One of the major advantages of network RTK is that you can receive corrections from a CORS network without setting up your own base station at the project site.

However, your receiver must support network RTK. If you have a compatible network rover, you can connect it directly to the CORS service.

3. Your GNSS Receiver and Field Controller

You will need your GNSS receiver and its compatible field controller or data collector.

Most GNSS receiver packages come with a controller and surveying software for configuring the equipment and carrying out field operations.

The controller is where you will typically configure your NTRIP connection, enter your CORS login details, select a mountpoint and monitor the correction status.

Depending on your GNSS model, the NTRIP settings may be found under options such as:

Survey Settings
Device Configuration
RTK Settings
Network RTK
NTRIP Client

The exact menu names will vary depending on the equipment manufacturer and surveying software.

You do not necessarily need a special controller just for CORS. What matters is that your existing controller and software support the required network RTK connection.

4. An Internet Connection: Where Does the SIM Card Go?

A CORS network sends correction data over the internet, so your GNSS equipment needs a working internet connection.

There are different ways to achieve this:

SIM card in the GNSS receiver: Some receivers have an inbuilt modem and SIM card slot, allowing them to access the internet directly.
SIM card in the field controller: Some controllers have their own SIM card slot and can provide internet access for the NTRIP connection.
Mobile hotspot: You can connect your controller or receiver to a mobile hotspot using a compatible Wi-Fi connection.

The option you use depends on the features of your GNSS receiver and controller.

One important thing to understand is that the SIM card does not automatically connect your receiver to CORS. It only provides internet access. You still need to configure the NTRIP settings using the connection details supplied by your CORS provider.

Also, ensure that you have sufficient data and a reasonably stable network connection at your project location.

5. Access to a CORS Network: Where Can You Get One in Nigeria?

Having a compatible GNSS receiver and internet connection is not enough. You also need access to a CORS network that can provide corrections for your project location.

This is where OTIC CORS comes in. OTIC CORS is available to surveyors across Nigeria, providing access to network RTK correction services without the need to establish a separate base station for every project.

Whether you are an independent surveyor, work with a surveying firm, or handle engineering and construction projects, you can create an account and get started.

To access the service:

Visit the OTIC CORS registration page.
Create your account via this link: https://corsdata.oticgs.com/rtk/register
Check service availability for your project location.
Confirm the applicable subscription or access arrangement.
Obtain your NTRIP connection details.
Before starting a survey, confirm that your project location is within the available service coverage.

6. Do you need to own a SinoGNSS receiver to use OTIC CORS?

You should not assume that CORS access is restricted to one GNSS brand. Compatibility depends on your receiver's ability to receive the correction format and connect through NTRIP, as well as the access arrangements for the service.

Contact OTIC Geosystems to confirm compatibility and the applicable access plan for your equipment.

7. Your NTRIP Connection Details

After registering with a CORS provider, you will need specific information to configure your GNSS receiver.

The network operator usually provides these details.

What is a mountpoint?

A mountpoint is the name of a particular correction stream available on an NTRIP caster.

Your CORS provider may have different mountpoints for different correction formats, reference station arrangements or service configurations.

You should not select a mountpoint randomly. Ask your provider which one is appropriate for your receiver and project location.

Once you have entered the correct details, your controller should be able to establish an NTRIP connection and receive correction data.

8. How Do You Know Your GNSS Receiver Is Successfully Connected?

This is where many surveyors need to pay attention. Entering your NTRIP details does not automatically mean that your GNSS receiver is ready for accurate RTK surveying.

The connection process has different stages:

First: NTRIP connection

Your controller should indicate that it has successfully connected to the NTRIP caster. If the connection fails, check your internet access, server address, port, and login details.

Second: Correction data reception

Your receiver should begin receiving correction data from the selected mountpoint. Check that the correction data is being received and that the data format is supported by your equipment.

Third: RTK solution status

Check the positioning status displayed on your controller.

You may see statuses such as:

FIX: The receiver has achieved a fixed RTK solution. This is generally the required solution status for high-precision RTK positioning.
FLOAT: The receiver is processing RTK corrections but has not resolved the carrier-phase ambiguities to a fixed solution.
DGPS/DGNSS: The receiver is using differential corrections but has not achieved a fixed RTK solution.
SINGLE: The receiver is operating without an RTK correction solution.

For cadastral and other high-precision surveying applications, do not assume that receiving corrections or seeing an RTK connection means your coordinates are ready for use. Allow the receiver to achieve FIX and carry out the necessary field checks before recording critical survey points.

9. What If Your GNSS Receiver Cannot Connect to CORS?

If you have entered your connection details but your receiver is not connecting, there are several things to investigate.

If the problem persists, contact your CORS provider or equipment supplier for assistance. The issue may be related to the receiver configuration, software compatibility, or the CORS service itself.

Get Started with OTIC CORS

You do not have to own a complete base-and-rover set before you can benefit from network RTK surveying.

If your GNSS receiver supports NTRIP, you can access correction data from a compatible CORS network through an internet connection.

OTIC CORS is here for all surveyors. Create an account, check the available service coverage for your project location, and get your connection details to start using the network.

Visit OTIC CORS to register Or register here

If you need help confirming whether your GNSS receiver is compatible or configuring your NTRIP connection, contact OTIC Geosystems for assistance via WhatsApp

At OTIC, we believe that access to modern surveying technology should go hand in hand with the knowledge to use it effectively.

What Do You Need to Connect Your GNSS Receiver to CORS in Nigeria?

What Do You Need to Connect Your GNSS Receiver to CORS in Nigeria?