Questions tagged [radar]
Radio detection and ranging devices. Operate by detecting and processing return echoes from objects and surfaces of signals at radio frequencies. Can be used to ascertain spatial coordinates and velocities, surface characteristics, object orientation, aid in object identification. In space applications used for tracking, radar imaging, rendezvous, collision avoidance, and other purposes.
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Is it easier to detect a satellite than an aircraft with a land-based radar?
I am suspecting that it is easier to detect a satellite because in the space, there is no other thing. In other words, the background is cleaner.
Is it right?
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A black cube 1 mile per side appears in geosynchronous orbit around the earth. Who would spot it and how would they do it? How easy would it be?
This is not intended to be a math question, so much as an understanding of how the current technology and techniques would view this problem.
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What are the differences (if any) between the techniques of range-rate and delay-doppler measurements?
This answer to How does an onboard atomic clock help interplanetary navigation? says:
Range-Rate is the two-way measurement of signals broadcast from one location on Earth, received and retransmitted ...
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Has Perseverance fired up its RIMFAX yet?
PIA24048: Testing RIMFAX for NASA's Perseverance Rover
Original Caption Released with Image:
A test model of the RIMFAX instrument — aboard the trailer behind the snow mobile — undergoes field ...
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Does transmitting from a few dishes significantly improve the performance of radar surveillance from Earth at GEO and beyond? If so, how exactly?
The BBC's US wants giant radar in UK to track space objects says:
Lt Col Jack Walker of the US Space Force told the BBC the US was "in discussion" with the UK about putting the radars "...
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Has there ever been an instance of asteroid discovery by radar; seen first by radar rather than being observed after optical discovery?
In a discussion below this answer to Can we use something like RADAR to detect asteroids? I'm complaining that the answer is essentially wrong;
Yes, radar is one of the useful tools for detecting and ...
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How do they know the sub-surface radar reflections (potential underground ice or "lakes") on Mars are not natural dielectric or metallic in origin?
Gizmodo's NASA Scientists Find More Subsurface Lakes on Mars links to Characteristics of the Basal Interface of the Martian South Polar Layered Deposits (paywalled, but there is this 52nd Lunar and ...
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How were winds measured for ascent trajectory calculations and checks for the Space Shuttle?
The Space Shuttle's ascent trajectory was calculated on the day of launch based on measured winds to avoid structural load exceedances. The winds continued to be measured until shortly before launch ...
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What was the most intense beam ever sent from Earth?
By a freak coincidence sensors on a passing alien ship a hundred light years away had picked up a faint artificial blip from Earth, thereby discovering our inhabited planet. But which blip was it?
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How (the heck) was coherent synthetic aperture radar (SAR) implemented using photographic emulsion aboard Apollo 17?
This answer to Is there really microfilm on the Moon? includes a block quote which includes the following subquote:
The equipment was installed in the service module and consisted of a coherent ...
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Does Falcon 9's first stage use laser, radar or vision to assist landing? [duplicate]
Does Falcon 9's first stage use only GPS when it makes its vertical precision landing, or is it assisted also by radar or laser ranging or computer vision? If not, why not?
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What is "TFR" in the context of operating a marine radar on top of a "water tower" at a launch site?
This answer to What is this propellor-like object on top of the SpaceX Hopper? includes the following:
FCC filing: Space Exploration Technologies Corp. 0459-EX-CN-2020:
...d) List any natural ...
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Did the Apollo LM's cockpit altitude displays account for the pointing angle of the radar altimeter?
The Apollo LM had a radar altimeter which was particularly critical in the final stages of landing. It could be set to two different pitch angles, either aimed backwards by 24º to be used during the ...
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Radar altimeter in a space shuttle
I was going through the Space Shuttle Handbook, chapter Guidance and Navigation.
In one of the Note boxes, it is written
Radar altimeter altitude is not used for navigation or guidance. The ...
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What are the pros and cons of Doppler radar versus Doppler lidar?
Some spacecraft designed for autonomous landing / hazard avoidance (such as Surveyor) use three-beam Doppler radar for range-rate measurements, and some (such as Morpheus) have utilized a three-beam ...
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