Sentinel-1 Reference Guide

This reference guide provides detailed information about Sentinel-1 SAR data parameters and options available through the Copernicus Data Space Ecosystem.

Note

New in version 0.1.20: Sentinel-1 SLC Burst Mode is now available! Search for individual bursts from SLC products with enhanced filtering capabilities. See the Sentinel-1 SLC Burst Mode guide for complete documentation.

Overview

Sentinel-1 is a constellation of two polar-orbiting satellites (Sentinel-1A and Sentinel-1B) carrying a C-band Synthetic Aperture Radar (SAR) instrument. The mission provides continuous all-weather, day-and-night imagery for land and ocean services.

Key Features: - C-band SAR instrument operating at 5.405 GHz - Four exclusive acquisition modes - Dual polarization capability (HH+HV, VV+VH) - 12-day repeat cycle (6 days with both satellites) - Global coverage - Individual burst access for SLC products (available from August 2, 2024)

Search Parameters

Parameter Types

When searching for Sentinel-1 data, parameters are passed in two ways:

  1. Direct Parameters: Passed directly to the search() method - collection_name - Mission/collection identifier - product_type - Product type (GRD, SLC, OCN, etc.) - orbit_direction - Orbit direction (ASCENDING/DESCENDING) - aoi_wkt - Area of interest in WKT format - start_date / end_date - Temporal range - top - Maximum number of results

  2. Attributes Dictionary

    Attributes are passed in the attributes parameter dictionary. All values listed below have been comprehensively tested and verified against the Copernicus Data Space OData API.

    Important

    API Compatibility Note

    This library uses the OData API, which has different parameter names than the OpenSearch/resto API:

    • ✓ platformSerialIdentifier (NOT platform)

    • ✓ instrumentShortName (NOT instrument)

    • ✓ operationalMode (NOT sensorMode)

    • ✓ swathIdentifier (NOT swath)

    • ✓ polarisationChannels (NOT polarisation)

    Note

    Usage Guidelines

    • processingLevel must be 'LEVEL1' (not 'L1' or '1')

    • polarisationChannels filters by single channel; products may contain multiple channels

    • Date ranges affect data availability: recent dates for near-real-time products

    • All attribute values are case-sensitive strings

  3. Method Parameters

    These parameters are passed directly to query_by_filter(), not in the attributes dictionary:

    • orbit_direction - Orbit direction ('ASCENDING' or 'DESCENDING')

Basic Parameters

Collection Name

Use 'SENTINEL-1' as the collection name.

results = searcher.search(collection_name='SENTINEL-1')

Geographic Parameters

Geometry

Region of Interest defined in Well Known Text (WKT) format with coordinates in decimal degrees (EPSG:4326).

# Polygon example
aoi_wkt = 'POLYGON((12.4 41.9, 12.5 41.9, 12.5 42.0, 12.4 42.0, 12.4 41.9))'
results = searcher.search(
    collection_name='SENTINEL-1',
    aoi_wkt=aoi_wkt
)

Product Parameters

Product Types

Sentinel-1 offers various product types for different applications:

# Search for GRD products
results = searcher.search(
    collection_name='SENTINEL-1',
    product_type='GRD'
)

Processing Level

Available processing levels:

  • LEVEL0 - Raw data

  • LEVEL1 - Single Look Complex (SLC) and Ground Range Detected (GRD)

  • LEVEL2 - Ocean (OCN) and other derived products

# Search for LEVEL1 products
results = searcher.search(
    collection_name='SENTINEL-1',
    attributes={'processingLevel': 'LEVEL1'}
)

Platform Serial Identifier

Sentinel-1 constellation satellites:

  • A - Sentinel-1A

  • B - Sentinel-1B

  • C - Sentinel-1C

# Search for Sentinel-1A data only
results = searcher.search(
    collection_name='SENTINEL-1',
    attributes={'platformSerialIdentifier': 'A'}
)

Swath Identifier

Filter by specific swath. This is an attribute-based search.

  • Stripmap (SM): S1 to S6

  • Interferometric Wide (IW): IW1, IW2, IW3

  • Extra Wide (EW): EW1 to EW5

  • Wave (WV): WV1, WV2

# Search for data from Stripmap swath S1
results = searcher.search(
    collection_name='SENTINEL-1',
    attributes={'swathIdentifier': 'S1'}
)

Instrument

  • SAR - Synthetic Aperture Radar

# Search for SAR instrument data
searcher = CopernicusDataSearcher()
searcher.query_by_filter(
    collection_name='SENTINEL-1',
    product_type='GRD',
    start_date='2015-06-01',
    end_date='2015-06-30',
    attributes={'instrumentShortName': 'SAR'},
    top=10
)
results = searcher.execute_query()

Operational Mode

Sentinel-1 operational modes:

  • SM - Stripmap mode

  • IW - Interferometric Wide swath mode (default)

  • EW - Extra-Wide swath mode

  • WV - Wave mode

# Search for Interferometric Wide swath data
searcher = CopernicusDataSearcher()
searcher.query_by_filter(
    collection_name='SENTINEL-1',
    product_type='GRD',
    start_date='2015-06-01',
    end_date='2015-06-30',
    attributes={'operationalMode': 'IW'},
    top=10
)
results = searcher.execute_query()

Mode Characteristics:

  • Stripmap (SM): 80 km swath, 5 m resolution, 6 beams (S1-S6)

  • Interferometric Wide swath (IW): 250 km swath, 5×20 m resolution, 3 sub-swaths

  • Extra Wide swath (EW): 400 km swath, 20×40 m resolution, 5 sub-swaths

  • Wave (WV): 20×20 km vignettes, 5 m resolution, for ocean applications

Orbit Parameters

Orbit Direction

  • ASCENDING - Satellite moving from south to north

  • DESCENDING - Satellite moving from north to south

results = searcher.search(
    collection_name='SENTINEL-1',
    orbit_direction='DESCENDING'
)

Orbit Number

Absolute orbit number (integer value or range).

# Single orbit
results = searcher.search(
    collection_name='SENTINEL-1',
    attributes={'orbitNumber': 12345}
)

Relative Orbit Number

Relative orbit number (1-175 for Sentinel-1), representing the orbit within a repeat cycle.

# Search for relative orbit 87
results = searcher.search(
    collection_name='SENTINEL-1',
    attributes={'relativeOrbitNumber': 87}
)

Polarization

Sentinel-1 supports various polarization combinations:

  • HH - Horizontal transmit, Horizontal receive

  • VV - Vertical transmit, Vertical receive

  • HH&VH - Horizontal transmit, Horizontal and Vertical receive

  • VV&VH - Vertical transmit, Vertical and Horizontal receive

  • VH&VV - Vertical transmit, Horizontal and Vertical receive

  • VH&HH - Vertical transmit, Horizontal and Vertical receive

  • HH&HV - Horizontal transmit, Horizontal and Vertical receive

  • VV&HV - Vertical transmit, Vertical and Horizontal receive

  • HV&HH - Horizontal transmit, Vertical and Horizontal receive

  • HV&VV - Horizontal transmit, Vertical and Vertical receive

# Search for specific polarization channel
searcher = CopernicusDataSearcher()
searcher.query_by_filter(
    collection_name='SENTINEL-1',
    product_type='GRD',
    start_date='2015-06-01',
    end_date='2015-06-30',
    attributes={'polarisationChannels': 'VV'},
    top=10
)
results = searcher.execute_query()

Note

polarisationChannels specifies individual channels (VV, VH, HH, HV). Products may contain multiple polarizations, but this filters by available channels.

Polarization by Mode: - IW and EW modes: VV+VH or HH+HV - SM mode: Single (HH, VV, HV, VH) or dual polarization - WV mode: Single polarization (HH or VV)

Quality and Timeliness

Timeliness

Data delivery timeliness categories:

  • NRT-10m - Near Real-Time within 10 minutes

  • NRT-3h - Near Real-Time within 3 hours

  • Fast-24h - Fast delivery within 24 hours

  • Off-line - Standard offline processing

  • Reprocessing - Reprocessed data

# Search for near real-time data
results = searcher.search(
    collection_name='SENTINEL-1',
    attributes={'timeliness': 'NRT-3h'}
)

Processing Baseline

Processing baseline version (affects product quality and algorithms used).

# Search for specific processing baseline
results = searcher.search(
    collection_name='SENTINEL-1',
    attributes={'processingBaseline': '003.40'}
)

Status

Product availability status:

  • ONLINE - Immediately available for download

  • OFFLINE - Requires retrieval from long-term storage

  • ALL - Both online and offline products

# Search for immediately available products
results = searcher.search(
    collection_name='SENTINEL-1',
    attributes={'status': 'ONLINE'}
)
results = searcher.search(
    collection_name='SENTINEL-1',
    status='ONLINE'
)

Practical Examples

Example 3: Ocean Applications

from phidown.search import CopernicusDataSearcher

searcher = CopernicusDataSearcher()

# Search for ocean products
searcher.query_by_filter(
    collection_name='SENTINEL-1',
    product_type='OCN',
    aoi_wkt='POLYGON((0 35, 10 35, 10 45, 0 45, 0 35))',  # Mediterranean
    start_date='2023-06-01',
    end_date='2023-06-30',
    top=50
)
ocean_results = searcher.execute_query()

# Search for wave mode data
searcher2 = CopernicusDataSearcher()
searcher2.query_by_filter(
    collection_name='SENTINEL-1',
    product_type='GRD',
    aoi_wkt='POLYGON((0 35, 10 35, 10 45, 0 45, 0 35))',
    start_date='2023-06-01',
    end_date='2023-06-30',
    attributes={'operationalMode': 'WV'},
    top=50
)
wave_results = searcher2.execute_query()

print(f"Found {len(ocean_results)} ocean products and {len(wave_results)} wave mode products")

Example 4: Time Series Analysis

from phidown.search import CopernicusDataSearcher
import pandas as pd

searcher = CopernicusDataSearcher()

# Search for consistent time series data
searcher.query_by_filter(
    collection_name='SENTINEL-1',
    product_type='GRD',
    aoi_wkt='POLYGON((12.4 41.9, 12.5 41.9, 12.5 42.0, 12.4 42.0, 12.4 41.9))',
    start_date='2023-01-01',
    end_date='2023-12-31',
    orbit_direction='DESCENDING',
    attributes={
        'operationalMode': 'IW',
        'relativeOrbitNumber': '87',
        'polarisationChannels': 'VV'
    },
    top=1000
)
results = searcher.execute_query()

# Group by date to analyze temporal coverage
results['Date'] = pd.to_datetime(results['ContentDate']).dt.date
temporal_coverage = results.groupby('Date').size()

print(f"Found {len(results)} products over {len(temporal_coverage)} unique dates")

Search Optimization Tips

  1. Use Relative Orbit Numbers: For time series analysis, filter by relative orbit number to ensure consistent geometry.

  2. Specify Orbit Direction: Choose ascending or descending based on your application needs.

  3. Filter by Polarization: Select appropriate polarization for your analysis (VV+VH for most land applications).

  4. Consider Processing Baseline: Newer baselines generally provide better quality but may not be available for historical data.

  5. Use Operational Mode Appropriately: - IW for most land applications (use attributes={'operationalMode': 'IW'}) - EW for wide-area monitoring (use attributes={'operationalMode': 'EW'}) - WV for ocean wave analysis (use attributes={'operationalMode': 'WV'})

  6. Check Product Status: Use attributes={'status': 'ONLINE'} for immediate download needs.

Common Use Cases

Land Applications: - Deforestation monitoring: IW GRD, VV+VH polarization - Urban change detection: IW GRD, VV polarization - Agricultural monitoring: IW GRD, VV+VH polarization

Ocean Applications: - Ship detection: IW GRD, VV polarization - Oil spill monitoring: IW GRD, VV polarization - Wave analysis: WV mode products

Interferometry: - Ground deformation: IW SLC, same relative orbit - Topographic mapping: IW SLC, interferometric pairs

Emergency Response: - Flood mapping: IW GRD, VV polarization - Disaster assessment: IW GRD, available polarization

Technical Specifications

Frequency: 5.405 GHz (C-band) Repeat Cycle: 12 days (constellation), 6 days (with both satellites) Orbital Altitude: 693 km Incidence Angle Range: 20-47 degrees Swath Width: - SM: 80 km - IW: 250 km - EW: 400 km - WV: 20 km

Spatial Resolution: - SM: 5 m (single-look) - IW: 5x20 m (single-look) - EW: 20x40 m (single-look) - WV: 5 m (single-look)

For more detailed information about Sentinel-1 specifications and applications, refer to the official ESA Sentinel-1 documentation.