=== versions ===
python 3.12.0 | pystac-client 0.9.0 | planetary-computer 1.0.0 | rasterio 1.5.2 | numpy 2.5.4 | scikit-image 0.26.0

=== STAC search ===
18 scenes from relative orbit 42 (ascending), 04 Jun to 25 Dec 2022
S1A_IW_GRDH_1SDV_20220908T133610_20220908T133635_044914_055D60_rtc
assets: vh, vv, tilejson, rendered_preview
polarisations: ['VV', 'VH'] | mode IW | pixel 10 m | ENL 4.4 | EPSG:32642
vv raster:bands: [{'nodata': -32768, 'data_type': 'float32', 'spatial_resolution': 10}]

=== speckle (10 m chip) ===
chip 603 x 659 pixels; linear gamma0 0.0009..30.54
pixel-to-pixel noise (median 5x5 std): raw 1.84 dB, Lee 0.65 dB

=== reading VV on a 40 m grid ===
2022-06-04: 100.0% valid, median -10.1 dB
2022-06-16: 100.0% valid, median -10.2 dB
2022-06-28: 100.0% valid, median -10.3 dB
2022-07-10: 100.0% valid, median -8.2 dB
2022-07-22: 100.0% valid, median -9.0 dB
2022-08-03: 100.0% valid, median -9.7 dB
2022-08-15: 100.0% valid, median -8.4 dB
2022-08-27: 100.0% valid, median -9.8 dB
2022-09-08: 100.0% valid, median -10.4 dB
2022-09-20: 100.0% valid, median -9.8 dB
2022-10-02: 100.0% valid, median -9.7 dB
2022-10-14: 100.0% valid, median -9.7 dB
2022-10-26: 100.0% valid, median -9.6 dB
2022-11-07: 100.0% valid, median -9.5 dB
2022-11-19: 100.0% valid, median -9.1 dB
2022-12-01: 100.0% valid, median -8.9 dB
2022-12-13: 100.0% valid, median -9.0 dB
2022-12-25: 100.0% valid, median -9.6 dB

=== Otsu threshold ===
VV threshold from 2022-09-08: -14.1 dB
median VV: water-side -19.8 dB, land-side -8.3 dB

=== flood extent ===
valid area: 8,095 km²
water on 2022-06-16: 958 km²
water on 2022-09-08: 2,470 km²
newly flooded: 1,933 km² (23.9% of the area)
water before but not after: 421 km²
pixels at least 3 dB darker: 2,432 km²; of the Otsu flood pixels, 97% dropped by 3 dB or more

=== water area through the 2022 monsoon ===
      date  water_km2  flooded_km2  valid_pct
2022-06-04        925           89      100.0
2022-06-16        958            0      100.0
2022-06-28       1065          162      100.0
2022-07-10        767          150      100.0
2022-07-22       1012          374      100.0
2022-08-03       1191          562      100.0
2022-08-15        912          490      100.0
2022-08-27       2156         1608      100.0
2022-09-08       2470         1933      100.0
2022-09-20       1807         1369      100.0
2022-10-02       1428         1022      100.0
2022-10-14       1281          872      100.0
2022-10-26       1112          713      100.0
2022-11-07        985          586      100.0
2022-11-19        874          482      100.0
2022-12-01        816          419      100.0
2022-12-13        768          366      100.0
2022-12-25        758          332      100.0
peak: 08 September 2022, 1,933 km² newly flooded

=== vector output ===
8,320 flood polygons, total 1,933 km², largest 1,208 km²