Radar question

[Dawn Thieme]

I'm posting this radar image because I've heard of this before, but can't think of what it's called. It's the part south of the radar that looks like when the radars used to show the sweeping arm motion.

 

[Dawn Thieme]

Never mind, the radar didn't show up like I wanted it to, and i don't know how to change it. It looked like a sliver of a piece of pie, I'd seen it before and couldn't remember what it was called. It did it two frames in a row. I really wanted to delete the post but couldn't figure out how.

If anyone has ever seen what I'm talking about on radar and know what it's called, I'd still like to know.

 

[rdale]

It was probably the sunrise or sunset spike, depending on what time of day you grabbed it. Google that and see if it compares.

 

[Mike Deep]

Good site for identifying and understanding radar artifacts, while we're on the subject: http://www.letxa.com/anomalyintro.php

 

[Dawn Thieme]

I saw it right before I posted it, around 12 noon or 12:30 pm, central time. I doubt it was sunrise or sunset spikes.

 

[Chris Vagasky]

For all interested, the image in question:

http://i44.tinypic.com/vpzspd.jpg

http://www.letxa.com/anomalyspokes.php

 

[Bobby Prentice]

These are interference spikes from an unknown radiation source such as another radar. They occur at sunrise and sunset because the sun is an excellent radiation source.

This web site has good information on other non-weather echoes:

Meteorology News: Doppler radar can detect more than just weather

 

[Greg Blumberg]

I can say this...they aren't sun radiation spikes. The radar image taken isn't anytime near sunrise and sunset. If I'm reading the times correctly, the radar image was taken around 1 PM. Anyways this has already been stated. My question is how long did the artifact exist on the radar? That might help determine what it was.

 

[rdale]

Chris answered it above - they are interference spokes.

 

[Chris Vagasky]

I can say this...they aren't sun radiation spikes. The radar image taken isn't anytime near sunrise and sunset. If I'm reading the times correctly, the radar image was taken around 1 PM. Anyways this has already been stated. My question is how long did the artifact exist on the radar? That might help determine what it was.

They only appeared in the one image, just a couple interference spokes. Not sure where the interference came from.

 

[Dave Marshall]

There are a number of powerful airborne military RADAR platforms that are in roughly the right frequency range to cause side-lobe jamming of NWS doppler radar systems, and I can think of two off hand that operate heavily in the NE/KS region. The short duration would suggest maybe one painted the radar site inadvertently while peaking at other practice targets. There aren't a whole lot of mobile civilian systems that would be capable of causing really intense spokes outside maybe DOW. If that site isn't prone to seeing those spokes frequently, it had to be something transitory.

Other possibilities could be tropospheric ducting messing with another nearby radar site, or maybe some large object getting in just the right location to turn it into a reflector.

 

[Dawn Thieme]

There two spikes, in two consecutive frames.

 

[Bobby Prentice]

A follow up comment...I've noticed a consistent radar interference source over central Kansas centered near Great Bend, KS (KGBD) the past few years. I typically notice it around mid-day, but I've never documented exact times. This source has been periodically generating radar spikes on all WSR-88D radars within 248 NM. I don't know what the source is, but the military is a likely candidate. There's not base near Great Bend that I am aware of, but it could be an airborne military training area.

 

[Dave Marshall]

Bobby, do these spikes occur on multiple radars at the same time, or various RADARs in the area are affected sporadically and independently? If it is active RF interference (as opposed to passive reflection/refraction), the spike appearance would indicate it's side lobe jamming rather than main lobe. Jamming that is striking the receiving antenna directly in the main radiation lobe produces more of a starburst effect usually.

 

[Chris Bowman]

There is a bombing range southwest of Salina. When you have a regional mosiac on they tend to radiate from the vicinity of the bombing range. I have always assumed that it's interference/jamming from whatever plane or planes are operating in the area.