Satellite Limitations

Spatial Resolution

The Agdir platform primarily uses Sentinel-2 imagery at 10 x 10 meter resolution. This means each pixel in the analysis represents a 10 m by 10 m area on the ground.

• You cannot see individual plants — the pixel value represents the average condition across the 10 m area.
• Small features (single trees, narrow paths, field edges) may not be resolved accurately.
• This resolution is well-suited for field-level management zones but not for plant-level diagnostics.

Cloud Cover

Clouds block satellite imagery. When clouds cover your field during a satellite pass, no useful optical data can be collected for that date. This is the single most common reason for gaps in analysis results.

• Extended cloudy periods (common in maritime climates) can create significant data gaps.
• Partial cloud cover may affect only portions of the field, producing incomplete results.
• Cloud shadows can also affect data quality even when the field itself is not under a cloud.

Revisit Frequency

Sentinel-2 satellites pass over the same location every 2–7 days, depending on latitude. Combined with cloud cover filtering, this means you can typically expect:

• 10–20 usable images over a 3-month growing season in Northern Europe.
• More frequent data in drier climates with less cloud cover.
• Fewer images during winter months when solar angle is low.

Interpretation Requires Field Knowledge

Satellite data shows what is happening in a field (e.g., low vigor in a specific zone) but not always why. Causes could include:

• Water stress, nutrient deficiency, pest damage, or disease.
• Soil type variations, drainage patterns, or compaction.
• Differences in crop variety, planting date, or management history.

Ground-truthing with field visits is recommended to validate satellite observations and identify root causes.

Cost-Effective Approach

The use of moderate-resolution Sentinel-2 data (freely available from the European Space Agency) makes the Agdir platform cost-effective for large-scale monitoring. Higher-resolution commercial satellites (sub-meter) exist but are significantly more expensive and not necessary for most field-level management decisions.