Extra Wide Swath

Sentinel-1 SAR User Guide - Extra Wide Swath

Similar to the IW mode, the Extra Wide (EW) swath mode employs the TOPSAR technique to acquire data over a wider area than for IW mode using five sub-swaths. EW mode acquires data over a 400 km swath at 20 m by 40 m spatial resolution.

EW SLC products contain one image per sub-swath and one per polarisation channel, for a total of five (single polarisation) or 10 (dual polarisation) images in an EW product.

The EW mode is aimed primarily for use over sea-ice, polar zones and certain maritime areas, in particular for ice, oil spill monitoring and security services. Like IW, EW mode can also be used for interferometry since it shares the same characteristics for burst synchronisation, baseline and Doppler stability.

The table below shows the main characteristics of the Extra Wide swath mode.

Table 1: Characteristics of Extra Wide swath mode
Characteristic Value
Swath width 410 km
Incidence angle range 18.9° - 47.0°
Sub-swaths 5
Azimuth steering angle ± 0.8°
Polarisation options Dual HH+HV, VV+VH
Single HH, VV
Maximum Noise Equivalent Sigma Zero (NESZ) -22 dB


The table below shows the incidence and off-nadir angles for Extra Wide swath mode beams.

Table 2: Angles for Extra Wide sub-swaths
Beam EW1 EW2 EW3 EW4 EW5
Off-nadir angles at
min orbit altitude [°]
17.94-26.07 26.02-30.66 30.61-35.10 35.06-38.66 38.63-41.20
Incident angles at
min orbit altitude [°]
20.00-29.20 29.15-34.47 34.41-39.66 39.60-43.89 43.86-46.97
Off-nadir angles at
max orbit altitude [°]
16.36-24.49 24.44-29.08 29.03-33.52 33.48-37.08 37.05-39.62
Incident angles at
max orbit altitude [°]
18.22-27.57 27.38-33.42 32.65-38.05 37.84-42.53 42.08-45.16

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