Satellite vs Drone vs Paid Imagery: What's Right for Your Farm?
Crop imagery now comes in three flavors: free public satellites, farm drones, and paid commercial satellite subscriptions. Each occupies a real niche, and plenty of money is wasted buying the wrong tier. Here is an honest comparison — including where the free option genuinely is the best tool, and where it is not.
The three options at a glance
Free public satellites (Sentinel-2). 10-meter resolution, frequent observations subject to cloud, acquisition coverage and service availability. Open Sentinel-2 imagery is free; processing services may have separate costs. This is what powers ndvi.us.
Commercial satellite subscriptions. 3-meter or better resolution with near-daily revisit from private constellations, sold through agritech platforms, typically as per-acre annual subscriptions. Sharper and more frequent than Sentinel-2, at a recurring price.
Resolution: how much detail do you actually need?
The instinct says "more detail is better," but resolution should follow the decision you are making.
- Zone-level decisions — where to scout, where to split fertilizer rates, which fields to prioritize — need to distinguish areas of a tenth of an acre or larger. The usefulness of Sentinel-2's 10-meter pixels depends on field shape, boundary mixing, image quality and the size of the pattern.
- Plant-level decisions — stand counts, precise weed mapping, spot-spray prescriptions, plant-by-plant disease detection — need centimeter imagery. Only a drone delivers this. The suitability of any sensor for plant-level analysis depends on its resolution, processing and the target crop.
- The 3-meter middle tier matters mainly for small or narrow fields (orchard rows, vegetable beds, plots under a quarter acre) where 10-meter pixels are too coarse to show internal patterns.
Revisit: how fresh does the data need to be?
Sentinel-2 offers frequent acquisitions, but usable observations depend on coverage, processing and local image quality. Commercial constellations image daily, which raises the odds of catching gaps between clouds. Drones fly under the clouds whenever you want, weather permitting.
Ask what decision actually needs daily data. Nitrogen zoning, irrigation fault detection, scouting priorities, and trend monitoring work fine on a 5-day rhythm. Time-critical windows — confirming hail damage for an insurance claim this week, monitoring a fast-moving disease outbreak — are where paying for daily revisit or a same-day drone flight earns its cost.
Cost: the arithmetic
For a 25-acre farm over one season:
The free tier is not a crippled trial; it is the same physical measurement (red and near-infrared reflectance) from a European Space Agency mission with a published accuracy record used in thousands of scientific studies. What you give up is spatial sharpness and revisit frequency — not measurement quality.
A practical decision guide
Stay with free Sentinel-2 if: your fields are over half an acre; your decisions are zone-level (scouting, split fertilization, irrigation checks, field triage); your budget for imagery is effectively zero; you are learning what satellite monitoring can do before spending anything.
Add a drone (owned or hired) if: you need plant-level detail for stand assessment or spot treatment; you manage high-value horticulture where single-plant problems are expensive; you need imagery on a specific day regardless of satellite schedules and clouds.
Consider a paid subscription if: your plots are small or narrow enough that 10-meter pixels blur the pattern; you operate at a scale where daily revisit changes decisions; or you need the workflow features (prescription export, team accounts, records) that platforms bundle with the imagery.
Combine tiers if you can. The most cost-effective setups on real farms use free satellite maps as the always-on early-warning layer, then deploy the expensive tool — a drone flight, an agronomist visit, a soil test — only where and when the free layer flags something. The free tier's job is to make sure every dollar of the paid tier lands on a real problem.
The bottom line
Compare current quotes and actual needs
Ask each provider about coverage, native resolution, quality masking, processing, revisit opportunities, export rights and total costs. Prices and included features vary. A free scouting tool does not replace services that supply calibrated statistics, specialist analysis or team workflows.
Interpretation and references
The map is a scouting aid. Displayed summaries are colour-derived estimates; cloud and shadow may remain after scene filtering. Check how ndvi.us works, and use the field checklist to record observations. Examples and suggested workflows are not verified field trials or guarantees of savings.