Time Inter-Comparison Using Transportable Optical Combs, Phase II

Metadata Updated: February 28, 2019

AOSense proposes a free-space, two-way optical time transfer system compatible with global-scale synchronization of current-generation optical atomic clocks. In Phase I, we have demonstrated the requisite performance using existing hardware coupled with off-the-shelf control electronics. Based on our results, we have designed a fully-integrated module capable of disseminating timing signals with sub-femtosecond error from 1-10,000 s. In Phase II, we will package the device and deliver it for external testing. Our system is expected to improve ground-to-satellite synchronization a million-fold over current RF-based time transfer systems, enabling applications including clock-based geodesy, very long baseline interferometry, coherent LIDAR arrays, and tests of general relativity. The Phase I breadboard demonstration performance is consistent with a timing jitter of 3 fs @ 1s and integrates down to 700 as at 30 seconds. The corresponding fractional timing instability is 3 x 10^-15 @ 1 second, which flickers at 2.7 x 10^-17 out to 2000 seconds. We have identified the systematic effects that limit both short and long term stability and incorporated the improvements into the Phase II design. With these improvements, we expect a 10x improvement in both short and long terms stability of the system. In addition, we reviewed and formalized the laser driver and control electronics specifications. The initial schematic capture for critical analog sub sections was completed and a suitable FPGA/microprocessor combination was chosen to control the system and process the timing information. Based on these designs, power and size estimates were used to complete the mechanical enclosure model for the time-transfer system. For maximum flexibility in the final architecture of the overall free-space time transfer system, each frequency comb sub-unit that includes the laser and control electronics will be housed in a 1U rack mount enclosure.

Access & Use Information

Public: This dataset is intended for public access and use. License: U.S. Government Work

Downloads & Resources


Metadata Created Date August 1, 2018
Metadata Updated Date February 28, 2019

Metadata Source

Harvested from NASA Data.json

Additional Metadata

Resource Type Dataset
Metadata Created Date August 1, 2018
Metadata Updated Date February 28, 2019
Publisher Space Technology Mission Directorate
Unique Identifier TECHPORT_93799
Maintainer Email
Public Access Level public
Bureau Code 026:00
Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
Metadata Catalog ID https://data.nasa.gov/data.json
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Harvest Object Id 562fecfd-1be4-4343-bef4-23270bcda542
Harvest Source Id 39e4ad2a-47ca-4507-8258-852babd0fd99
Harvest Source Title NASA Data.json
Data First Published 2019-05-01
Homepage URL https://techport.nasa.gov/view/93799
License http://www.usa.gov/publicdomain/label/1.0/
Data Last Modified 2018-07-19
Program Code 026:027
Source Datajson Identifier True
Source Hash ca3a30e9deb4c2bd8539342a01efad689b58121f
Source Schema Version 1.1

Didn't find what you're looking for? Suggest a dataset here.