Why shouldn’t all nodes be the same?

“The nodes we produced until this point were tailored to fully autonomous recording,” says Tom O’Toole from STRYDE when we met up for a conversation. “You put them in the ground, leave them to record and retrieve them when the survey is done.”

This concept has worked for many projects, which explains why STRYDE has been able to quickly conquer the onshore node market since its launch in 2019.

“But we did experience questions from our clients at the same time,” says Tom, who has been working in technology development for STRYDE for over five years. “Three themes kept coming up. First, wireless node health QC is still seen as essential in some quarters. Second, GNSS is essential for time-synchronised seismic data, but reception can be challenging in certain onshore environments. Could we find a way to ensure timing accuracy in case GNSS signal gets lost? Third, seismic contractors are taking on an increasingly diverse range of survey types. Could we develop a more broadband sensor to better serve these varying needs?”

“Hearing this feedback, we realised that no single node could solve all these challenges simultaneously without being financially prohibitive. Instead, we chose to develop a family of three nodes that work together to address these combined challenges.  The orange node continues STRYDE’s heritage of fully autonomous recording, with no radio comms and minimum cost. The white node includes wireless connectivity for node health QC. The blue node adds dual-clock technology to improve timing accuracy. The “Halo” node family is built on an evolved piezoelectric sensor and electronics platform that delivers broader sensing bandwidth from 0.5 to 200 Hz – it used to be 1 to 125 Hz – and lower noise and higher sensitivity,” explains Tom.

“By simply walking or driving past the white or blue node, you can check in on the device and perform a quick QC using a simple app running on your phone. We are already using drones for this type of work as well, which is especially useful in terrain where driving or walking are not easy options.”

The blue node is the most technologically advanced and focuses on the time synchronisation challenge. “Accurate time recording is fundamental to seismic acquisition,” says Tom, “and without it you cannot reliably synchronise recordings between individual nodes. That’s the reason why, to this day, cables are still used in some onshore environments.”

“Our new blue node addresses this issue with its dual clock technology, typically allowing up to 7 days of recording without GNSS. This facilitates operations in areas like marshes and dense forest that are characterised by difficult GNSS conditions, and even makes it possible to shoot nodal seismic in places like tunnels.”

“With this family, we can match the node mix to the job: orange where autonomous recording is sufficient and unit cost is the priority, white where real-time QC is needed, and blue where timing accuracy is critical. That flexibility means we can continue to make seismic acquisition accessible to industries where it is needed but has previously been out of reach,” concludes Tom. “Not all nodes need to be the same.”