Giddierone
Senior Member.
The Sentinel 1(a) satellite captures Synthetic Apature Radar images (SAR).
It scans a 250km wide swath of earth surface (interferometric wide swath mode, or IW), traveling on a sun-synchronous, polar-orbiting plane.
It's images frequently feature what appear to be diffraction spikes, with their four points are orientated along the ground track of the satellite.
Source: https://sentiwiki.copernicus.eu/web/s1-mission#S1-Mission-SAR-Instrument
It doesn't look directly down but at an angle between 29-46 degrees.
Source: https://sentiwiki.copernicus.eu/web/s1-mission
Vessels at sea (and wind turbines) tend to produce a consistent spike— often very large. For example this image of Shanghai Port is reminiscent of a Hubble Space telescope image of stars.
Spikes on land seem less common.
I noticed this one in Cologne Germany.
Source: https://browser.dataspace.copernicu...e3D="MAPZEN"&cloudCoverage=30&dateMode=SINGLE
It appears to come from a particualr building.
RWE Energy company. https://www.rwe.com/der-konzern/rwe-power/
The spike appears over numerous dates, and changes orientation (presumably when captured by the satellite on a different path—perhaps coming the oposite way) so doesn't appear to be a chance glinting reflection.
E.g. this image shows a much smaller spike with the points rotated from the previous image.
I'm curious to know what might cause the spike, and why it seems to be consistently associated with that particular building.
There are other spikes in the same scan swath on that same date, but this one seems quite distinct.
Looking at other sites like solar farms, radio telescopes, nuclear power stations, green houses etc — which I'd assumed might all have a high radar reflectance don't seem to produce such a distinct cross-shaped spike.
But, why does this building produce a spike like it's a ship at sea?
It scans a 250km wide swath of earth surface (interferometric wide swath mode, or IW), traveling on a sun-synchronous, polar-orbiting plane.
It's images frequently feature what appear to be diffraction spikes, with their four points are orientated along the ground track of the satellite.
Source: https://sentiwiki.copernicus.eu/web/s1-mission#S1-Mission-SAR-Instrument
It doesn't look directly down but at an angle between 29-46 degrees.
Source: https://sentiwiki.copernicus.eu/web/s1-mission
Vessels at sea (and wind turbines) tend to produce a consistent spike— often very large. For example this image of Shanghai Port is reminiscent of a Hubble Space telescope image of stars.
Spikes on land seem less common.
I noticed this one in Cologne Germany.
Source: https://browser.dataspace.copernicu...e3D="MAPZEN"&cloudCoverage=30&dateMode=SINGLE
It appears to come from a particualr building.
RWE Energy company. https://www.rwe.com/der-konzern/rwe-power/
The spike appears over numerous dates, and changes orientation (presumably when captured by the satellite on a different path—perhaps coming the oposite way) so doesn't appear to be a chance glinting reflection.
E.g. this image shows a much smaller spike with the points rotated from the previous image.
I'm curious to know what might cause the spike, and why it seems to be consistently associated with that particular building.
There are other spikes in the same scan swath on that same date, but this one seems quite distinct.
Looking at other sites like solar farms, radio telescopes, nuclear power stations, green houses etc — which I'd assumed might all have a high radar reflectance don't seem to produce such a distinct cross-shaped spike.
But, why does this building produce a spike like it's a ship at sea?