SPOT 4 (1998–2013). Two changes from SPOT 1–3:

• HR-VIR replaced HRV — adds a mid-IR (SWIR) band at 1.58–1.75 µm at 20 m. Useful for vegetation stress, snow/ice discrimination, and geology.
• VEGETATION-1 instrument — a wide-field sensor flown alongside HR-VIR.
  • Swath 2 250 km, 1 km resolution at nadir.
  • Bands: Blue 0.43–0.47 µm, Red, NIR, Mid-IR.
  • Daily global coverage — enables vegetation time series similar to AVHRR/MODIS.