Tag: SAR
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Russian Satellite Shadows Finnish Commercial Spacecraft Aiding Ukraine
The close approach began in late September and culminated in mid-October. The maneuver has drawn attention from experts who are examining why Russia carried out the move and what it signals about the use of commercial space assets in wartime. The Russian satellite closed in on the Finnish spacecraft over roughly two weeks. Analysts are…
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Russian Military Satellite Parks Within 5 Kilometers of ICEYE Radar Spacecraft
Defence Blog reported on October 18 that Russian satellite Kosmos 2612 adjusted its orbit on October 16 to close on ICEYE-X36, operated by the US division of the Finnish-founded company. The maneuver follows a pattern of earlier approaches toward the same satellite. Astrophysicist and independent satellite tracker Jonathan McDowell identified the maneuver using updated orbital…
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How Reliable Is Satellite Soil Moisture at Field Scale?
Satellite soil moisture can help identify drying trends, track surface wetting and prioritize agricultural inspections. Whether it can support decisions for an individual field depends on what the product estimates, the area each estimate represents and how it performs against local measurements. A map displayed at 30 metres does not necessarily contain independent 30-metre observations.…
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How to Identify Crop Types with Limited Ground Truth
Satellite imagery can help identify what farmers are growing, even when field observations are limited. But a detailed crop map needs more than an image and a classification algorithm. It needs reference labels that match the location and growing season, observations that capture crop development, and independent checks of the results. When those ingredients are…
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Can Satellite Imagery Detect Oil Spills on Land?
Satellite imagery can help identify some oil spills on land, particularly where contamination is exposed, sufficiently extensive, and observable in suitable spectral bands. It can also reveal surface changes that warrant investigation. But a dark patch near an oil well, an unusual soil color, or declining vegetation does not by itself confirm petroleum contamination. For…
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Can Satellite Imagery Detect Selective Logging?
Satellite imagery can detect some selective logging, particularly when tree removal creates visible canopy gaps, new access routes or repeated changes in the radar signal. However, detecting a large clear-cut is a different task from identifying scattered tree removal beneath a mostly intact canopy. The reliability of the result depends on the disturbance footprint, forest…
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What Can Satellite Imagery Actually Tell You About Crop Health?
Satellite imagery can reveal where crop growth is uneven, how vegetation changes through the season, and which areas deserve closer inspection. It can also support estimates of canopy cover, biomass and water-related conditions. But a vegetation map does not, by itself, establish whether a crop is diseased, short of water or likely to produce a…
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Satellite Revisit Time vs. Actual Monitoring Frequency
A satellite may be able to revisit your site every few days, yet the interval between usable images can be much longer. Clouds, acquisition schedules, viewing conditions and delivery requirements all affect when a new observation becomes useful. For monitoring projects, the key question is not simply how often a satellite can see the target,…
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Why Satellite Monitoring Fails Under Cloud Cover — and When SAR Helps
A satellite may pass over a mine, port or infrastructure corridor on schedule and still produce no usable optical view of the site. Clouds can hide the ground, while cloud shadows and haze can make visible areas unsuitable for reliable analysis. Synthetic aperture radar (SAR) can maintain observations through cloud cover and darkness, but it…
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How AI Detects Flood Changes Across Optical and SAR Images With Few Training Pairs
In brief: Instead of separately mapping water in pre- and post-flood images and then overlaying the results, the method first maps water features from optical and SAR imagery into a more consistent semantic space, then directly identifies where water conditions have changed. More importantly, it does not require large numbers of real flood-change labels: it…