Sentinel-1 RTC and GRD missing data

[natborn2]

There are some missing items in Sentinel-1 RTC and GRD collections. I searched a particular bounding box for items since the start of the year and found 2 items in RTC, 3 items in GRD, compared with 4 items in Copernicus.

The 1 item missing from both GRD and RTC is dated 20260211 so this may be a processing delay in MPC (?).
But the 1 item missing from RTC that is present in GRD is dated 20260118.

Up to December 2025 this AOI was receiving regular updates at 12-day revisit in the RTC collection.

import planetary_computer
import pystac_client

catalog = pystac_client.Client.open(
    "https://planetarycomputer.microsoft.com/api/stac/v1",
    modifier=planetary_computer.sign_inplace,
)

# RTC search
search = catalog.search(
    collections=["sentinel-1-rtc"], 
    datetime="2026-01-01/2026-02-16",
    bbox=[116.89457,2.35293,116.97763,2.41432],
    query={"sat:relative_orbit": {"eq": 105}}
)
items = search.item_collection()
print(f"Found {len(items)} items")
for item in items:
    print(item.id)

Found 2 items
S1A_IW_GRDH_1SDV_20260130T215833_20260130T215858_063002_07E7C0_rtc
S1A_IW_GRDH_1SDV_20260106T215835_20260106T215900_062652_07DAC0_rtc

GRD search

search = catalog.search(
    collections=["sentinel-1-grd"], 
    datetime="2026-01-01/2026-02-16",
    bbox=[116.89457,2.35293,116.97763,2.41432],
    query={"sat:relative_orbit": {"eq": 105}}
)
items = search.item_collection()
print(f"Found {len(items)} items")
for item in items:
    print(item.id)

Found 3 items
S1A_IW_GRDH_1SDV_20260130T215833_20260130T215858_063002_07E7C0
S1A_IW_GRDH_1SDV_20260118T215834_20260118T215859_062827_07E17A
S1A_IW_GRDH_1SDV_20260106T215835_20260106T215900_062652_07DAC0

Copernicus search

https://browser.dataspace.copernicus.eu/?zoom=13&lat=2.39&lng=116.94&themeId=DEFAULT-THEME&visualizationUrl=U2FsdGVkX1%2BoBE4B0yYhHUlI6jUWB3PHy1v5jqwGQacP%2BXUXEbpaHAeMfDSvxJMFEFxQ35O9fxxJYBGTowxuSOCV9wPVz6ES2xtZROn%2FqDmlL4LHWWLAqTQHM1H6nhSg&datasetId=S2_L2A_CDAS&fromTime=2026-02-13T00%3A00%3A00.000Z&toTime=2026-02-13T23%3A59%3A59.999Z&layerId=1_TRUE_COLOR

Copernicus lists 4 items in relative orbit 105 for the same location and dates:
S1A_IW_GRDH_1SDV_20260211T215833_20260211T215858_063177_07EE44_418C
S1A_IW_GRDH_1SDV_20260130T215833_20260130T215858_063002_07E7C0_4CAF
S1A_IW_GRDH_1SDV_20260118T215834_20260118T215859_062827_07E17A_9B44
S1A_IW_GRDH_1SDV_20260106T215835_20260106T215900_062652_07DAC0_1368