SAR/Remote Sensing Engineer — Industrial Site Change Detection (Sentinel-1)

Overview: We are looking for a remote sensing engineer with hands-on Sentinel-1 SAR processing experience to deliver a validated change detection analysis over a major industrial site. This is a focused, well-scoped first project with strong potential for ongoing technical engagement. All project details beyond this posting are subject to NDA prior to commencement of work. We need someone who works with raw radar backscatter data and understands what it means physically. This is not a GIS mapping project. Primary Site: Escondida Copper Mine, Chile Coordinates: 24°15'S, 69°04'W Deliverables: Deliverable 1 — Preprocessed Image Stack Process a minimum of six Sentinel-1 GRD image acquisitions over the Escondida site spanning the last 18 months. Preprocessing must include: -Orbit file application -Thermal noise removal -Radiometric calibration -Terrain correction using an appropriate DEM (SRTM or Copernicus DEM) -Speckle filtering (Lee or Refined Lee filter preferred) -Co-registration of image pairs for change detection Document the total number of acquisitions processed and any acquisitions rejected due to data quality issues and why. Deliverable 2 — Area of Interest Definition Define a precise polygon AOI over the primary concentrate stockpile area specifically — not the full mine footprint. Use available optical imagery (Google Earth, Planet, or Sentinel-2) to identify and validate the correct stockpile location before applying the SAR analysis. Document why the AOI was defined where it was. We need to be able to defend this decision to a technically sophisticated audience. Deliverable 3 — Change Detection Output Produce a quantified backscatter change analysis across the image pairs specifically within the defined AOI. Output must include: -A calculated percentage change between each image pair -Identification of statistically significant change events with your significance threshold defined and justified -Visual outputs showing the AOI at each acquisition date -A simple spreadsheet with one row per image pair showing date, backscatter value, and percentage change Deliverable 4 — Volumetric Estimate Convert the backscatter change data into an estimated volumetric change figure in metric tons. Document explicitly: -The bulk density assumption used and its source -The geometric assumptions made in the conversion -The error bounds on the estimate -Any conditions under which the estimate would be unreliable This is the most important deliverable. Assumptions must be documented explicitly — not hidden. Deliverable 5 — Retrospective Validation Cross-reference your change detection outputs against BHP's publicly available quarterly operational reviews for the same 18-month period. BHP publishes Escondida copper production figures quarterly — these are your ground truth reference. For each significant change event identified in Deliverable 3 document: -The date of the SAR-detected change -The direction of change (drawdown or accumulation) -The magnitude of the estimated volumetric change -The subsequent BHP quarterly figure and whether it directionally confirms the SAR signal -The approximate lead time in weeks between SAR detection and public data confirmation Accurate negative results are as valuable as positive ones. If the signal does not lead public data, we need to know that. Deliverable 6 — Methodology Documentation A clear written document covering: -Every preprocessing step applied and the parameters used -The change detection approach and why it was selected -The volumetric conversion methodology -Known limitations and failure modes of the approach -Recommendations for improving the methodology in subsequent analyses This document must be detailed enough that another qualified SAR engineer could reproduce your results independently. Technical Requirements: Candidates must have demonstrable experience with: -Sentinel-1 GRD and/or SLC data processing -SNAP (Sentinel Application Platform), Google Earth Engine, or equivalent -Python with relevant geospatial libraries (rasterio, GDAL, pyroSAR, or equivalent) -SAR backscatter change detection methodology -Experience with open-pit mine or industrial site imagery preferred but not required Please do not apply if your experience is limited to optical imagery, GIS mapping, or desktop GIS tools without SAR-specific processing experience. This project requires genuine SAR backscatter expertise. Screening Questions: Include your answers to all three questions in your application. Question 1: What preprocessing steps would you apply to a Sentinel-1 GRD image before running change detection, and why does each step matter? Question 2: How would you define and validate an AOI over a specific industrial feature — such as a concentrate stockpile — within a larger mine site, and what data sources would you use to confirm you have the right location? Question 3: What is the primary limitation of using Sentinel-1 spatial resolution for volumetric estimation at an open-pit mine site, and how would you account for it in your methodology? Timeline: Initial results within 14 days of project start. Full deliverable package within 21 days. If this timeline is not achievable state your realistic timeline in your application. Budget: $800–1,500 fixed price depending on experience and methodology quality. We are not looking for the cheapest option — we are looking for the most technically rigorous one. If your experience warrants a higher rate make the case in your application and we will consider it. Ongoing Engagement: This is the first project in a longer-term technical program. The right candidate will have the opportunity to take on additional site analyses and expanded scope as the platform develops. We are open to discussing a structured ongoing relationship with candidates who demonstrate exceptional technical judgment and genuine interest in the broader mission. To Apply: Submit your proposal including: -Answers to all three screening questions -Relevant experience with SAR data specifically -Examples of previous remote sensing work if available — academic papers, portfolio projects, or GitHub repositories are all acceptable -Your proposed methodology for this specific project in two to three sentences -Your timeline and fixed price Before work commences, selected candidate will be required to sign a standard NDA and IP assignment agreement.