Proposal for logging ONIX timestamped data #19
Description
- Proposed
- Prototype: Not Started
- Implementation: Not Started
- Specification: Not Started
Summary
This proposal aims to provide an end-to-end specification for efficiently logging and recovering for analysis all data recorded from ONIX systems with the Aeon low-level API.
Motivation
The ONIX acquisition system already knows how to decode and record signals from the Harp Synchronization Clock, but ultimately the timestamping of all ONIX streams is still done with the native system clock on a sample-by-sample basis.
The goal of this proposal is to provide an Aeon compatible specification for designing ONIX data readers allowing transparent time indexing of ephys data using Harp. The goal is to allow ephys data to be accessed in exactly the same way that any other data stream is accessed in the Aeon low-level API.
Detailed Design
TBD:
- Include first ONIX timestamp in each chunk with the chunk log file name to allow faster file lookups
- Chunk ONIX timestamps themselves by hour (or possibly more frequently than hourly)
- Infer chunk automatically from ONIX timestamp using a reference epoch (using ONIX time)
- Update acquisition modules both to upgrade ONIX and implement this new logging scheme
- Lookup how best to map across sample counter, ONIX time and Harp time