Earth Observation Payload GNSS Engineer
Direct Entry Job Permanent Glasgow, UK
Uploaded 12 Oct 2021
Spire Global is a space-powered data and analytics company that offers unique insights and powerful solutions about the Earth from space, so that organizations can act now and plan for the future with confidence, accuracy and speed. Leveraging its proprietary multi-purpose satellite constellation, global ground station network, cloud data infrastructure, and sophisticated predictive analytics, Spire gives commercial and government organizations an unprecedented competitive advantage to solve their toughest challenges, empowered with knowledge from space.
Spire’s Earth Intelligence (EI) Team is growing a portfolio of Earth observations and position, navigation, and time (PNT) products ranging from atmospheric profiles and surface soil moisture to GNSS systems monitoring. Our products rely on unique measurements collected by our growing constellation of nanosatellites. As Earth Observation Payload GNSS Engineer at the EI Team, you will join the STRATOS payload group. The latter is laser-focused on delivering critical meteorological data powering weather prediction models worldwide, by leveraging GPS / GNSS Earth remote-sensing techniques such as GNSS radio-occultations and GNSS reflections.
You will primarily own the GNSS qualification, acceptance, and quality testing processes of the STRATOS payload that collects critical weather data. You will work with the world’s premier nanosatellite Earth observations and GNSS team to maximize the quality of the remote-sensing data collected and produced by our software-defined payloads. In this role, you will focus on guaranteeing that the raw data observables produced by the STRATOS payloads installed in our satellites meet the highest quality standards. This responsibility involves areas such as (not exhaustive): the acceptance tests performed during the payload manufacturing process, the payload qualification tests performed on every new design version release of either the payload or the satellite platform, or contributing to the refinement of the payload internal signal acquisition and tracking algorithms that produce the primary raw data observables. Depending on your experience and / or interest, this role will also allow you to expand your range of responsibility in areas such as actively participating in the development of the internal signal processing algorithms of the STRATOS payload, or taking ownership of the design of the digital filters of the payload front-end.
If you have the drive and motivation to ideate and deploy the critical testing and quality control processes that guarantee the reliability of the raw remote-sensing data delivered by a satellite payload that has global impact, we’d love to hear from you.
Responsibilities of your role:
- Own the design, execution, reporting, and maintenance of the flight acceptance tests that are applied to each STRATOS payload unit manufactured. This involves both module-level and satellite integrated-level tests.
- Be responsible for the detection, location and root cause determination of failures during the aforementioned module-level and satellite integrated-level tests of the STRATOS payload and manage the deployment of the necessary fixes (when this is possible), with support from manufacturing and engineering teams.
- Be intimately familiar with all relevant high-level design details of every new version release of the STRATOS payload module (e.g., the performance figures you would find in a datasheet or product HW manual).
- Own the design, execution, reporting, and maintenance of the flight qualification tests that assess the end-to-end SNR performance of each new design release of the STRATOS payload.
- On each new design version or SW major release of the STRATOS payload, lead the execution and post-analysis of the release validation tests that check the quality of the raw observables data produced by the payload.
- Own the maintenance of the STRATOS payload test rig, by ensuring it is always in working condition, and the user documentation is up to date.
- When required, support the bench-testing activities in the lab of new payload types for new Earth observation missions where GNSS / geolocation technologies are involved.
Basic Qualifications / Experience:
- Master or PhD degree in Electrical Engineering, Aerospace Engineering, Physics or Mathematics; or equivalent expertise acquired through demonstrated professional practice.
- Demonstrated understanding of the GNSS signal structures, GNSS navigation principles, and PNT user algorithms of GNSS receivers.
- Familiarity with the navigation user interface specification documents of the GNSS systems (eg: GPS-IS-200, GALILEO OS-SIS-ICD, etc.)
- Demonstrated working knowledge of the internal signal acquisition and tracking algorithms of GNSS receivers.
- Experience using a high-end GNSS signals simulator (eg: SPIRENT, IFEN, OROLIA, etc.)
- Experience in testing high-end GNSS receiver boards, evaluating the quality of the raw observables and the real-time PNT solutions they produce.
- Professional experience with one scripting language, such as (not exhaustive): Bash, Python, Ruby, MATLAB, Octave, or a combination.
- Hands-on experience analysing and extracting statistical information (mean, median variance, standard deviation, linear regression ) from large amounts of test data, including data collection and sorting, scripted processing, statistics calculation, data visualization, and hypothesis testing.
- User-level experience with Unix / Linux systems, close familiarity using shell command lines
- Experience calculating link budget for line-of-sight radio links (received power and received SNR).
- Familiarity with antenna working principles and a solid understanding of its electrical performance parameters as a system, including radiation pattern, gain, directivity, polarization, ohmic and total efficiency, input impedance and return loss.
- Familiarity with radio receiver architectures and a solid understanding of its main performance parameters as a system, including total noise figure, total system noise temperature, total gain, reception bandwidth, compression and 3rd order intercept point.
- Experience using the following laboratory test equipment: multi-channel power supplies, multi-channel multimeter, oscilloscope, spectrum and vector network analyzers, RF signal generators, connectorized (box-based) RF/microwave devices such as amplifiers, filters, splitters, attenuators, bias-tees, etc.
- Some experience dealing with RF electromagnetic compatibility and radiated interference issues, preferably in the field of GNSS / RF receivers testing.
- Some experience conducting measurements inside an RF anechoic chamber
- A detail-oriented personality; careful, methodological, and persistent in tracking down problems.
- Diligent worker, with good documentation / reporting habits
- Able to communicate effectively, promptly raising issues to the team co-workers or manager when problems or concerns arise.
- Comfortable and familiar working with on-line documentation, such as Google docs, spreadsheets, etc.
Desirable Qualifications / Experience:
- Experience designing and evaluating the performance of the internal GNSS receiver algorithms that perform signal acquisition and tracking and produce the raw observables and PNT solution
- Practical experience designing base-band digital filters (FIR, IIR) for an RF front-end and its implementation, either with dedicated digital circuits in an FPGA or via SW DSP algorithms.
- Familiarity with Earth remote sensing techniques using GNSS signals, such as GNSS reflections (sensing of Earth surface soil moisture or sea roughness) , GNSS radio occultations (sensing of Earth atmosphere), GNSS altimetry (measuring height of smooth surfaces, such as calm waters or sea ice cover with centimeter-level precision)