Which Skylark Variant Fits Your Use Case?

GNSS corrections technologies have evolved over time, leading to a variety of approaches that continue to coexist due to their unique advantages and limitations. From Differential GNSS (DGNSS) to Precise Point Positioning (PPP) and Real-Time Kinematics (RTK), each technology excels in addressing specific challenges but may fall short in others. These differences make it necessary to tailor corrections solutions to the diverse requirements of modern applications.

Skylark^® Precise Positioning Service embraces this complexity by offering three distinct variants: Skylark Nx RTK, Cx, and Dx. Each variant is optimized for a specific set of use cases, allowing customers to choose the right solution that balances performance and practicality for their application.

This article aims to provide a detailed exploration of Skylark’s three variants, helping users understand how each is tailored to meet their specific needs. First, we will delve into the technological differences and capabilities of each variant, followed by guidance on selecting the best variant for your application, and how to get started.

For a refresher on the fundamentals of different corrections technologies, check out this blog post.

Skylark Nx RTK

Skylark Nx RTK is a Network RTK service designed to deliver the highest level of precision with centimeter-level accuracy. It provides 1-2 cm accuracy with instant convergence, ensuring rapid and reliable results for demanding applications. The service utilizes a Virtual Reference Station (VRS) system, which dynamically places a virtual base station near the rover.

Unlike traditional linear interpolation methods, Skylark Nx RTK leverages Swift’s advanced atmospheric modeling to estimate local conditions with greater accuracy. This approach enables extended baselines, offering centimeter-level accuracy as far as 70 km away from a physical base station, compared to traditional RTK baselines of around 30 km.

Skylark Nx RTK is compatible with any RTK receiver that supports RTCM 3.1 or RTCM 3.2 MSM 5, making it versatile for various setups. The service supports multiple reference frames, including ITRF2020, NAD83, ETRS89, and DREF91, ensuring compatibility with diverse geospatial requirements.

Skylark Cx

Skylark Cx is a PPP-RTK service designed to provide uniform centimeter-level accuracy across continents. It achieves 3-7 cm accuracy with fast convergence time of under 20 seconds, and this performance does not degrade with increasing distance from base stations, ensuring consistent results over entire countries.

The service supports both OSR (Observation Space Representation) and SSR (State Space Representation) correction data formats, offering flexibility and compatibility with a wide range of GNSS receivers. It is compatible with receivers that support RTCM 3.2 MSM 4 & 5, ensuring seamless integration across various hardware setups.

Thanks to Skylark’s robust cloud architecture hosted on AWS and its SSR delivery option, Skylark Cx is scaled to support billions of simultaneous users, making it ideal for large-scale deployments such as automotive fleets and is already trusted by over 10 million vehicles worldwide. The first cloud-based correction service to ever be ISO 26262 certified for Automotive Safety Integrity Level B (ASIL-B), Skylark Cx delivers high-integrity positioning for safety-critical products and applications. This ensures compliance with stringent automotive hardware safety standards, enabling safe and reliable operation in complex environments. Furthermore, Skylark Cx comes with a commercial SLA that guarantees accuracy, reliability, and availability, offering peace of mind for mission-critical deployments.

Skylark Dx

Skylark Dx is a DGNSS service that provides uniform sub-meter accuracy with low data and power consumption. This makes it ideal for applications where efficiency and simplicity are key priorities. The service delivers instant convergence, with performance that remains consistent regardless of the distance from base stations.

The lightweight data transmission of Skylark Dx is optimized for bandwidth-sensitive applications, ensuring reliable performance even in low-bandwidth scenarios. It is also highly efficient in terms of power consumption, making it suitable for battery-operated devices such as IoT sensors, wearables, and asset trackers.

Skylark Dx operates effectively in environments with constrained antennas or low signal-to-noise ratios, ensuring reliable performance in challenging conditions. It is compatible with a wide range of GNSS receivers that support MSM 1, further enhancing its versatility for various industries and applications.

How to Choose Between the Three Variants?

Selecting the right Skylark variant depends on your application’s requirements for accuracy, coverage, and complexity. Each variant offers unique benefits, making them suitable for different use cases.

Skylark Nx RTK: Maximum Accuracy

If centimeter-level accuracy and immediate convergence are critical, Skylark Nx RTK is the optimal choice. Its advanced atmospheric modeling and Virtual Reference Station system make it ideal for high-precision applications requiring maximum accuracy and extended baseline coverage. Skylark Nx RTK eliminates the complexities of setting up and maintaining a local base station or the unpredictability of low-grade RTK networks, offering a more reliable and scalable solution.

Examples: 

• A surveying company mapping intricate details of a construction site relies on Skylark Nx RTK for its 1-2 cm accuracy, regional coverage, and ability to choose between different reference frames.
• A robotic lawnmower navigating residential or commercial properties uses Skylark Nx RTK to maintain centimeter-level accuracy, ensuring clean, consistent mowing patterns while avoiding obstacles and boundaries, and without the burden of deploying a local base station.

Skylark Cx: Scalability and Safety

For applications requiring continent-wide coverage and fast convergence but without the need for maximum accuracy, Skylark Cx offers an excellent balance. Its PPP-RTK technology ensures reliable 3-7 cm accuracy, delivering uniform performance across vast regions, regardless of proximity to base stations. Skylark Cx, ISO 26262 certified for Automotive Safety Integrity Level B (ASIL-B), meets the most rigorous automotive safety standards, ensuring cloud-based GNSS corrections comply with stringent benchmarks required for automotive hardware, enabling safe and reliable operation for vehicles in complex environments at scale.

Examples: 

• An automotive manufacturer implementing advanced driver-assistance systems (ADAS) benefits from Skylark Cx's scalability and reliability across large geographic regions, ensuring vehicles maintain uniform accuracy regardless of distance from base stations.
• A delivery company managing a fleet of autonomous delivery vehicles uses Skylark Cx to ensure precise route execution and reliable performance across multiple cities and regions, improving efficiency and customer satisfaction.

Skylark Dx: Simplicity and Efficiency

For low-power and bandwidth-sensitive devices that prioritize coverage and ease of deployment over centimeter-level accuracy, Skylark Dx provides uniform sub-meter accuracy at minimal cost and complexity. This makes it ideal for battery-operated applications, including mobile phones, wearables, and asset trackers.

Examples: 

• A logistics company tracking shipping containers in urban and remote areas uses Skylark Dx to achieve reliable sub-meter accuracy while conserving device power and data bandwidth, ensuring efficient operation without added complexity.
• A fitness tracker worn by runners and cyclists relies on Skylark Dx for accurate distance and route tracking, balancing sub-meter accuracy with low power consumption to extend battery life while maintaining affordability.

Getting Started

Skylark’s three variants are designed to address specific positioning needs while balancing trade-offs in accuracy, coverage, and complexity. Whether you require the pinpoint accuracy of Skylark Nx RTK for surveying and robotics, the continent-wide scalability and safety compliance of Skylark Cx for automotive and fleet applications, or the low-power simplicity of Skylark Dx for IoT and asset tracking, Skylark provides a tailored solution for every use case. By offering these options, Skylark empowers industries to achieve precise positioning without compromising on practicality or efficiency, ensuring the right balance of performance and affordability for their unique requirements.

Getting started with Skylark is simple. If you already have a GNSS receiver, check which Skylark variants it is compatible with here. Once you've confirmed compatibility, head over to the Skylark User Portal to sign up for the variant that best suits your needs. You will receive the NTRIP credentials to enter into your receiver and start using Skylark immediately.

If you are still exploring your options or making design decisions, our experts are here to help. Reach out to us via our contact form, and we’ll guide you toward the ideal Skylark solution for your application.

You can also purchase from our selection of Skylark-compatible evaluation kits from leading GNSS hardware manufacturers at the Skylark Evaluation Store. You will receive a 6-month free trial for each of the supported Skylark variants.