Range Rings and Radar Sites

Harold Rutila · « **on:** February 22, 2010, 05:33:37 AM »

Are the centers of range rings on radar scopes associated with the location of the radar site? And does anyone know where I could see the locations of those sites? I've tried looking around on Google without any results.

Gary Millsaps · « **Reply #1 on:** February 22, 2010, 05:59:53 AM »

Hi Harold,

Indeed the range rings on the older radar systems (ARTS series) are centered on the actual radar antenna site - known as the "Main Bang." The primary radar beam being transmitted and received via the parabolic dish and the secondary 'firing' from the antenna block that rides atop the main dish. As for the newer systems, I believe the rings can be displayed wherever the controller specifies but am unsure on this. I think the same is true for mosaic radars as well.

As for the antenna locations..that info was available in the DAFIF/USFIF data information. It is also shown on some radar video display maps but would be a visual representation only.

Andrew Doubleday · « **Reply #2 on:** February 22, 2010, 06:57:01 AM »

Try looking through this site... I recently added the locations as "fixes" into the ZLA sector file for radar centering...

https://nasea.faa.gov/index.cfm/news/event_...p;NameLike=C%25

I'll try to dig up the file I had with recent locations later for you...

-AJ

Harold Rutila · « **Reply #3 on:** February 22, 2010, 07:19:00 AM »

Gary and AJ, thanks for the quick responses! AJ, on the NAS ES Portal, where should I be looking? It looks like they recently updated the site. In particular I'm looking for the radar sites of the Potomac Consolidated TRACON, and I can only find a "surveillance facility" in Baltimore, MD. Is a surveillance facility what they consider a radar site?

Alex Evins · « **Reply #4 on:** February 22, 2010, 09:00:46 AM »

You can also find radar sites and their types on FlightExplorer.

Arthur Heiser · « **Reply #5 on:** February 22, 2010, 04:35:28 PM »

Quote from: Harold Rutila

Gary and AJ, thanks for the quick responses! AJ, on the NAS ES Portal, where should I be looking? It looks like they recently updated the site. In particular I'm looking for the radar sites of the Potomac Consolidated TRACON, and I can only find a "surveillance facility" in Baltimore, MD. Is a surveillance facility what they consider a radar site?

Yes, the "S" in ASR, ARSR, PSR, and SSR stands for "surveillance".

ASR - Airport Surveillance Radar (primary TRACON sites)
ARSR - Air Route Surveillance Radar (primary ARTCC sites)
PSR - Primary Surveillance Radar (this is what gives you the primary targets, ones without any data for what they are squawking)
SSR - Secondary Surveillance Radar (when the radar hits a target that is squawking a code that has corresponding information, this is what allows that information to be translated to the data blocks)

PSR and SSR are combined into ASR. If you take a look at a picture of an ASR-9 or ASR-11, the PSR is the parabolic dish on the lower, and the SSR is the flat, rectangular portion that sits on top of the PSR dish.

[img]http://www.radartutorial.eu/19.kartei/pic/img2031.jpg\\\" border=\\\"0\\\" class=\\\"linked-image\\\" /]

From tooling around on the site that AJ (Doubleday) posted, I cannot seem to find anything on the exact coordinate locations of these sites, just the relative city location.

Gary Millsaps · « **Reply #6 on:** February 22, 2010, 04:57:47 PM »

Quote from: AJ Heiser

From tooling around on the site that AJ (Doubleday) posted, I cannot seem to find anything on the exact coordinate locations of these sites, just the relative city location.

And sad to say, you're not likely to...the exact locations have been taken out of the public realm for security reasons.

Arthur Heiser · « **Reply #7 on:** February 22, 2010, 05:02:01 PM »

Quote from: Gary Millsaps

And sad to say, you're not likely to...the exact locations have been taken out of the public realm for security reasons.

Yea I can see why they would not disclose that info, but it's also interesting that ASR's are so out in the open in the first place. If some one wanted to take one out, they aren't "hidden" by any means.

Alex Evins · « **Reply #8 on:** February 22, 2010, 06:20:38 PM »

You can determine the coordinates of radar sites on Flight Explorer.

Harold Rutila · « **Reply #9 on:** February 22, 2010, 07:05:59 PM »

Quote from: Alex Evins

You can determine the coordinates of radar sites on Flight Explorer.

This appears to be the only way to do it. Thanks, Alex.

And thanks to everyone else for the contributions. Radar units are a neat subject that we don't get to explore much here.

Andrew Doubleday · « **Reply #10 on:** February 24, 2010, 12:19:49 AM »

Harold,

Found the file I was using. It's a little out of date, but you my find fairly accurate locations in here. This one gives you ASR site coordinates organized by state.

http://www.filmxpress.net/ftpuser1/FAA%20D..._200904/asr.dat

I had a text document from a friend that contained ARSR sites... I seem to have misplaced that one, however. I will try to contact him for it if you are in need of those.

Regards,

AJ

Arthur Heiser · « **Reply #11 on:** February 24, 2010, 08:30:54 AM »

Quote from: Andrew Doubleday

I had a text document from a friend that contained ARSR sites... I seem to have misplaced that one, however. I will try to contact him for it if you are in need of those.

I'd like to see those.

Nate Johns · « **Reply #12 on:** February 25, 2010, 09:46:30 PM »

Quote from: Gary Millsaps

And sad to say, you're not likely to...the exact locations have been taken out of the public realm for security reasons.

Security... now that's just this side of hilarious.

Not saying you're wrong about what they did, not at all, in fact you're probably right. Just an example of people who think they are securing things when it's literally impossible.

I'm just saying that if someone thinks that in this day in age that hiding the exact coordinates of the whereabouts of a large golf ball that sits outside in generally prominently visible areas often covered by satellite imagery that is easily and freely publicly accessible is just hilarious.

Examples:
Parker ARSR (ZDV) People drive by this site thousands of a times a day on the way to school or otherwise.

West Mesa ARSR (ZAB) Almost anyone in Albuquerque can see this thing with a clear view of the west side. Or heck, drive out to Route 66 Casino and Resort and see it on your right just off I-40.

Heck... I just Googled "Silver City ARSR" and found this document:
http://www.foia.af.mil/shared/media/docume...-091009-033.pdf

Ahh, "security"...

~Nate

Harold Rutila · « **Reply #13 on:** February 25, 2010, 10:54:11 PM »

Are the white covers something new as part of the security initiative, or have those always been part of ARSRs? Why aren't there covers on the ASR-9s/ASR-11s? I really have no reasoning other than that ARSRs can be a backup for ASRs with their longer range...but still, covering up the rotating dish probably does nothing. Either that or covers/domes weren't considered for ASRs because they're older. No clue, realy. Just rambling.

Arthur Heiser · « **Reply #14 on:** February 26, 2010, 03:46:35 PM »

Quote from: Harold Rutila

Are the white covers something new as part of the security initiative, or have those always been part of ARSRs? Why aren't there covers on the ASR-9s/ASR-11s? I really have no reasoning other than that ARSRs can be a backup for ASRs with their longer range...but still, covering up the rotating dish probably does nothing. Either that or covers/domes weren't considered for ASRs because they're older. No clue, realy. Just rambling.

The white covering you see is called a radome.

[!--quoteo(post=0:date=:name=radome.org)--][div class=\\\'quotetop\\\']QUOTE (radome.org)[/div][div class=\\\'quotemain\\\'][!--quotec--]For demanding radar, telemetry and communications systems, radomes safeguard against environmental concerns, such as wind, blowing sand, snow, ice, rain, ultra violet sun light, temperature, fungus and corrosion.[/quote]

ASR's are short range radar and, in one particular TRACON, there may be multiple ASR sites for the TRACON to use. One may be the primary, one a backup, or ASR's can be assigned to be used by sectors within a facility in order to optimize coverage assurance. For this reason, I believe there is no need for a radome covering an ASR. Also, ASR's are much smaller than ARSR's and are less susceptible to the conditions listed above.

Because ARSR's are so much bigger than ASR's (because they are LRR instead of SRR), the scan time, the time for the rotating dish to complete one revolution, is longer than that of an ASR. ARSR's scan at a rate from 10 to 12 seconds, while ASR's can scan at a rate as low as 4 seconds. This makes sense because in a terminal environment, you are going to want a quick "refresh" time because the density of aircraft is so much greater than that of the enroute environment.

ARSR's are really in no means supposed to be backups's to ASR's. ARSR's are the primary radar used by center sectors within an ARTCC, although ASR's feeds primarily for TRACON's can be piped in to ARTCC's to increase coverage.

References:
http://radome.org
http://www.radomes.org/museum/satellite.php

The latter is a great resource for information on quite a plethora of sites.