---
title: "Researchers Detect 76 Space Objects in Sentinel-1 Radar Data"
id: 220702
type: "post"
slug: "researchers-detect-76-space-objects-sentinel-1-radar-data"
author: "NSE"
published: "2026-11-11T14:37:35+00:00"
modified: "2026-11-11T14:37:35+00:00"
canonical: "https://newspaceeconomy.ca/2026/11/11/researchers-detect-76-space-objects-sentinel-1-radar-data/"
markdown_url: "https://newspaceeconomy.ca/2026/11/11/researchers-detect-76-space-objects-sentinel-1-radar-data.md"
description: "A November 9 preprint reports detections of 76 cataloged space objects in Sentinel-1 recordings and blind recovery of two selected debris encounters."
language: "en-US"
category:
  - "Current News"
  - "Space Economy"
post_tag:
  - "Orbital Debris"
  - "RADAR"
  - "Satellite Tracking"
  - "Sentinel"
  - "Synthetic Aperture Radar"
---

# Researchers Detect 76 Space Objects in Sentinel-1 Radar Data

Researchers identified 76 cataloged space objects in Sentinel-1 radar recordings collected on six calendar days, according to a [preprint posted November 9](https://arxiv.org/abs/2611.12158). The detections included satellites, rocket bodies, and debris at distances of 41.7 to 492.9 kilometers from the observing spacecraft.

The study, led by Juha Vierinen with researchers at UiT The Arctic University of Norway and the Swedish Institute of Space Physics, was submitted to Acta Astronautica. It reprocessed recorded radar signals to follow objects moving through the radar beam.

Most detections used cataloged orbits to guide the search. A separate blind search recovered two selected debris encounters without using their orbital predictions during detection. Measurements from a short encounter also refined an existing orbit estimate.

The [paper’s sensitivity calculation](https://arxiv.org/html/2611.12158v1) estimated detection of conducting spheres about 3.4 millimeters across with Sentinel-1 and 0.6 millimeters with EarthCARE at 10 kilometers. Those modeled values assume receiver noise and coherent signal integration limited by beam-transit time, capped at 10 milliseconds. Reflections from Earth increased the background in the actual Earth-looking observations.

## An Earth-Mapping Instrument

Sentinel-1 is part of Europe’s Copernicus Earth-observation program. Its [C-band synthetic aperture radar](https://www.esa.int/articles/about-us/directorates/earth-observation-programmes/copernicus/sentinel-1/introducing-the-sentinel-1-mission) collects imagery during the day or night and through cloud cover. Radar transmits radio pulses and measures returning echoes, so observations do not depend on sunlight illuminating the target.

The mission’s ordinary products support sea-ice monitoring, ship detection, oil-spill surveillance, and measurements of land movement. Synthetic aperture processing combines observations acquired as the spacecraft moves, producing detailed images of the surface.

The new study uses recordings from that Earth-observation instrument for a different target: objects between spacecraft and ground. Its findings concern signals recovered from existing measurements, placing another use alongside the surface-monitoring functions for which the mission was built.

## Sentinel-1A’s Recorded Impact

Sentinel-1A itself experienced a particle impact on August 23, 2016. [ESA](https://www.esa.int/)’s [contemporary investigation](https://blogs.esa.int/rocketscience/2016/09/01/sleuthing-a-space-collision/) documented a sudden reduction in solar-array power, a change in orientation, and a small change in orbit. Controllers switched on cameras originally installed to check solar-array deployment and obtained visual evidence of damage.

The power reduction was less than 5% of total solar-panel generation, according to [ESA](https://www.esa.int/)’s September 2016 account, and the satellite continued routine operations. Its attitude-control system compensated for the orientation change.

That event illustrates the physical interaction behind debris-monitoring work: a small, fast-moving object can transfer momentum to a spacecraft and damage exposed equipment. In the November 2026 study, the researchers used radar echoes to obtain information about passing objects, including their distance and motion relative to the observing satellite.

![Preprint reports 76 cataloged space objects detected 41.7 to 492.9 kilometers from Sentinel-1, with two selected debris encounters recovered in a blind search.](https://i0.wp.com/newspaceeconomy.ca/wp-content/uploads/2026/11/sentinel-1-space-object-detections.png?resize=696%2C464&ssl=1)