User talk:Monopulse01

Welcome[edit]

Welcome!

Hello, Monopulse01, and welcome to Wikipedia! Thank you for your contributions. I hope you like Wikipedia and decide to stay. Here are some pages that you might find helpful:

I hope you enjoy editing here and being a Wikipedian! Please sign your name on talk pages using four tildes (~~~~); this will automatically produce your name and the date. If you need help, check out Wikipedia:Questions, ask me on my talk page, or place {{helpme}} on your talk page and ask your question there. Again, welcome! - Ahunt (talk) 16:03, 31 December 2010 (UTC)[reply]

Secondary surveillance radar[edit]

I removed your recent edits to this article and restored the previous version. The text you put in here really overlaps the article Aviation transponder interrogation modes, which is why the "Main" template is there. I would have moved it there myself, but it was almost entirely unreferenced. You really need refs to add large text additions like that, so if you have refs I suggest you add the text to Aviation transponder interrogation modes. - Ahunt (talk) 16:01, 3 January 2011 (UTC)[reply]

Ahunt

I am new to editing Wikipedia and do not know how to contact you. I was in the process of editing and had not finished. there are plenty of referenced to add.

Please restore the deleted contribution which took me several hours to write and I do not have a copy.

I hope that you can read this

Michael Stevens

No problem you can contact me right here. That is good that you have references for all that text, but part of what I pointed out is that that section was long ago split into a different article, Aviation transponder interrogation modes, which is where I think your new text with refs should go. Your text is safe and sound in the history of the article. To find it you just have to click on "View history" in the top righthand corner at Secondary surveillance radar and then pick the last version you worked on. That is one of the great advantages of Wikipedia, nothing is ever lost here it is always retrievable. I would suggest you take the text from there and work it into the Aviation transponder interrogation modes article. If you have more questions please do post them here and I'll respond. - Ahunt (talk) 18:17, 3 January 2011 (UTC)[reply]

Thanks for your reply.

I hope that you are not the original author of Aviation transponder interrogatio modes because I find it is a little short on detail, particualrly interrogation pulse spacings. In including mode pulse spacings in the SSR article I was intending to explain why P1-P2 were crucial to Mode S. I then wanted to go on to ACAS and ADS-B which are further extentions to Mode S. Also to explain that monopulse was developed for Mode S not MSSR.

I was the designer of the original monopulse SSR receiver - ref 6 and also the author of the (still) only book solely devoted to SSR - ref 1. During the CAA/FAA joint development of Mode S, I was part of the UK team and attended all meeting between the two authorities. I designed and ran the experimental UK Mode S equipment to prove the principles. The UK commissioned the first operational MSSR system, which I designed, and also the second which was the Canadian RAMP project. I think that I have some knowledge of the subject. Now I am helping my son design some ADS-B equipment so am keeping up to date although now retired.

I must disagree with you that transponder modes are separate from the ground equipment. They are all an indivisable part of one system and each has to work with the other and I feel strongly that they must be part of the same article. Apart from Mode S, transponder modes are largely now history. Sorry again if you are the author of the article.

I am quite happy to produce draft material for you to review if you can tell me how to do it. Perhaps I am being too long winded. Perhaps the history of the development is not of great interest. I was about to describe how the Ullyatt paper was key to how the UK and US came to development a common system. Please advise.

Michael

Hi again, no I didn't write that article, if I had it would be better than it is! That article was split off from the SSR article just due to length, not because it isn't part of the same subject. On Wikipedia we try to keep the articles down to about 50 KB and that was getting a bit long and also with too much emphasis on that one aspect so it was split off. Have a look at Wikipedia:Article size for some guidance on that subject. As far as the subject goes, no I don't think you are being long winded at all, detail is good as long as you have refs to cite. If you wrote them then that is fine too, I have quoted refs I have written quite often, as long as they are third-party published (see WP:SPS). - Ahunt (talk) 20:24, 3 January 2011 (UTC)[reply]

Mr Hunt. I understand the reasons for keeping articles as short as possible. I have not yet found how to determine the length of an article but note that sizes are given on the revision history page and so far this article has not exceeded 14 KB. I would like to continue contributing to this article but have a difficulty in that in order to explain how Mode S was designed to be compatible with the existing Modes A and C I have to refer to ground interrogator pulse spacings, particularly P1 and P2. Also the limitations of the aircraft replies to those interrogations. The so called main article "Aviation transponder interrogation modes" does not do this and I have no intention adding to that article which I now regard as dated. It was a mistake in 2009 to separate the modes of communication between ground and air from the article on SSR as that is exactly what SSR is about. Anyway the furure is now with Mode S and its more recent derivatives TCAS and ADS-B.

If my table of modes and pulse spacings is causing embarrasment I am prepared to delete it. I only need to refer to Modes A and C and only included the others for completeness.

I would like to continue with your revision of 15:56, 3 January. If I edit this version what happens when I save it?

Michael

That all makes sense and yes you can revert to that version and carry on from there. If you edit that version and save it it becomes the new "current version" and changes after that are lost (except they remain in the history of course). Your new additions were fine, just unreferenced and overlapped "Aviation transponder interrogation modes", other than that there were no issues I saw. Since you know a lot about the subject and have looked though "Aviation transponder interrogation modes" do you think it would make more sense to re-incorporate that information into Secondary surveillance radar (or at least what makes sense to bring back) and then redirect "Aviation transponder interrogation modes" to SSR? In looking though the history of both articles and their talk pages there was never any discussion or consensus to split any content to "Aviation transponder interrogation modes", so there is no real need to gain a new consensus to reincorporate it.- Ahunt (talk) 18:04, 4 January 2011 (UTC)[reply]

I will do this and incorporate material from the other paper. We can then agree whether it needs to remain as a separate article. I note that Wikipedia has very good articles on TCAS and ADS-B so I will not need to cover these topics in any depth. How does the "Contents" box get generated and what decides where it is placed in the artical? I must be careful not to change things just because they are not presented in the way that I would have done but do you think that the section on "Monopulse secondary surveillance radar" should come before "Operation" and "Modes" and not after? Unless the first mentioned should be part of "Overview". The summary at the top of the paper "Secondary surveillance radar (SSR)" is fine but why is "Monopulse secondary surveillance radar (MSSR) included and if it should then should I add "Mode S", "TCAS" and "ADS-B" here too? I would prefer to merge it all into one paragraph. Monopulse01 (talk) 13:35, 5 January 2011 (UTC)[reply]

The table of contents is generated automatically, so don't worry about it, if you title sections the table will pick them up all by itself. Your ideas here sound just fine, I would suggest just go ahead and do it, but ensure that you add in references as you go. Go ahead and reorder the existing sections if you think it will make for a better logical flow. Let me know when you are done and I'll have a look and clean up any formatting that needs fixing. You can incorporate any text you think needs moving from the other article (by copying not removing), just include in your edit summary that it was moved from "X' article to keep the copyrights intact. After you are done I'll have a look and see if the other article can be just redirected. Since you are the subject matter expert and I understand Wikipedia (to some extent) between us we should be able to get the article improved and referenced well! Let me know if any of this doesn't make sense!! - Ahunt (talk) 13:51, 5 January 2011 (UTC)[reply]

I just looked the article over and made a few formatting changes. I assume you are going to add refs to the new text and finish the Mode S section? I'll leave the rest until you indicate you are done. - Ahunt (talk) 18:19, 6 January 2011 (UTC)[reply]

Thats fine. I have more to add then I must read it through and polish up. I did quite a bit of work before lunch and left it unsaved only to find that I had been timed out and lost it all. I wish that there was a spell checker.Monopulse01 (talk) 19:11, 6 January 2011 (UTC)[reply]

Well if you use a browser with spell-checking (Google Chrome, Chromium (web browser), Mozilla Firefox) that will do it, or you can do your drafting off-line in a text editor or even a word processor and then copy and paste it into the page after spell-checking. Also if you time out you can just open another window or tab for Wikipedia and sign back in and your original window will hold your text without losing it. - Ahunt (talk) 19:33, 6 January 2011 (UTC)[reply]

I do not know if you can help but something has gone wrong with my section on Standards and specifications. I want it to read ICAO (International Civil Aviation Organization), RTCA (...), etc. with the acronyms in bold. Each has an associated reference. I will add other references as I retrieve the documents and check their contents.

Let me have a look. I did some fixing up there earlier. As per WP:MOS bolding is only used in articles under certain circumstances and acronyms within text isn't one of those. Also external links aren't used in article text as per WP:EL, but can be used as references instead. Normally organizations mentioned that have their own articles would be wikilinked to those articles. I'll go over the article and add in standardized formatting, links etc. - Ahunt (talk) 23:40, 7 January 2011 (UTC)[reply]

Okay I had a look and formatted the organization names as per the manual of style. Technically the abbreviations for the names shouldn't even be in the article, since they aren't used again and therefore don't serve any purpose, but I left them in for now. The abbrevs don't get bolded as per the WP:MOS. I also tagged places that need references added, but I know you said that you have those to add yet. I also fixed a few minor spelling and formating items - you can see them all in the article history. I am still concerned that we now have a large overlap with Aviation transponder interrogation modes and that the overlap between that and Secondary_surveillance_radar#Interrogation_Modes section should be resolved either by moving content from Aviation transponder interrogation modes back and redirecting the article, or moving content from the section to the other article. It just doesn't make sense to have the information split in two places - makes it hard for readers to follow. What do you think on that issue? - Ahunt (talk) 00:27, 8 January 2011 (UTC)[reply]

The acronyms should stay as they are in common usage and I suspect that some users have never thought what the letters actually stand for - however also my spelling them out is, I think, also important as it gives a context for the organisation. I like my articles to be self standing and for the reader only needing to look up a reference to obtain more detail if he needs it. The other article is rather trivial and some of the references dubious and unhelpful. In trying to answer your earlier comment I have deleted any reference to military modes and left it to this one to cover. I ask if you can be patient until I finish. It is taking rather a long time as it is a big subject and I cannot devote all my time to it. Please continue to tag places needing references and I will get round to them in due course. I will also help me understand how another reader views the article. I have a problem in inserting references as they usually appear in a completely different place towhere I left the curser. I then have to drag it back to the required position.Monopulse01 (talk) 09:30, 8 January 2011 (UTC)[reply]

No problem, Wikipedia has no deadlines! Not sure about the ref issue you mention, it sounds like a browser problem. Not sure what browser you are using, but since you mentioned the lack of spell-checking I suspect it could be Internet Explorer. IE is an appalling bad browser, non-standards compliant and doesn't interact with pages correctly, not to mention lacks spell-checking. You might want install a better browser like Mozilla Firefox or Google Chrome, both free, both 100% standards compliant and both include spell-checking. Either will make editing a lot easier! - Ahunt (talk) 14:00, 8 January 2011 (UTC)[reply]

Can you help please. I wish to upload a number of diagrams which are mine but which I have used in a number of articles. I expect that I will have to get clearance. I have read the help files but cannot understand how to upload the first example which is on my computer not on a websiteMonopulse01 (talk) 16:10, 8 January 2011 (UTC)[reply]

As long as you hold the copyrights to the diagrams (and haven't signed them away with the publishing deal) then you are free to upload them to Wikipedia or better yet, Wikimedia Commons and licence them freely under a Creative Commons Licence or release them as Public Domain. If the rights are held by the publisher, then yes you would have to get permission to re-licence them, or you could create new diagrams instead if you prefer. - Ahunt (talk) 16:37, 8 January 2011 (UTC)[reply]

I just wanted to remind you that Wikipedia articles cannot be used as a ref for Wikipedia articles, please see WP:CIRCULAR. - Ahunt (talk) 17:45, 12 January 2011 (UTC)[reply]

Thanks, I had not been aware. I have used Wikipedia articles where possible. Should I have avoided them? I have now covered all the contents of "Aviation transponder interrogation modes" except for IFF for which I have provided a Wikipedia link to a much more comprehensive and informative article. The ATIM article is not a main article and I think that it is misleading to infer that it is. It amounts to little over two pages with few references. I think it is now time to to drop the claim that it is a main article.Monopulse01 (talk) 11:26, 13 January 2011 (UTC)[reply]

The problem is that by itself Wikipedia is not a reliable reference. Rather than try to use Wikipedia articles as refs for Wikipedia articles, which leads to a bootstrapping problem, it is better to go to the other article and then have a look though its refs and see if any are suitable to use in the first article. One thing to be aware of is that because Wikipedia is now ten years old that in some cases unreferenced information taken from it has been used in other articles and websites and then those have been used as refs for the original Wikipedia article, again creating a "bootstrap" problem of circular referencing. That way incorrect information can be widely spread and seemingly well referenced.

As far as Aviation transponder interrogation modes goes, if all the information has been reincorporated back into SSR then I think it should be redirected back into SSR and not left out there. Otherwise we have two articles on the same subject that say different things. I have not checked to see if there are any useful refs in that article that could be transfered back. Perhaps you would be the best judge of that.

We also need to get much better and more complete referencing for SSR or else editors will slowly start removing tagged text as original research. - Ahunt (talk) 15:08, 13 January 2011 (UTC)[reply]

Thank you for your comments. Can you define what "tagged text" means. There is no original research reported. Everything is covered in at least one of the 20 references used so far. I will be away for 10 days from next Sunday and I am not sure how much time I can spend on this until Sunday80.229.227.134 (talk) 16:14, 13 January 2011 (UTC)[reply]

"Tagged text" just means text that has a "citation needed" tag on it. As per WP:V everything tagged has to have a footnote as a ref or else it can be challenged and removed. There is no time limit, but it would be good to add references as footnotes sooner rather than later. Right now large areas of text in the article look like it could be original research or even copied from a book (copyright violations) and the addition of footnotes will allow people to double check the text to ensure it isn't either of those. - Ahunt (talk) 16:20, 13 January 2011 (UTC)[reply]

I have just read through both articles and we still have a problem with Aviation transponder interrogation modes as the information there on Modes 1-5 is not present in the SSR article, nor is the detail on ICAO 24-bit addresses. I realize that these modes (except 3) aren't really used any more, but the article needs to cover them for historical reasons. This means that we need to either move content from Aviation transponder interrogation modes to SSR or vice versa. - Ahunt (talk) 17:55, 13 January 2011 (UTC)[reply]

The reference to IFF is contained in the first line of "Secondary Radar" under "Identification Friend or Foe". It is another Wikipedia site like "Aviation transponder interrogation modes". The 24 bit address is described in ref [13] mentioned in the 4th paragraph under "Developments to address the above deficiencies" and the allocation of the addresses in ref [14] in the same paragraph.80.229.227.134 (talk) 18:42, 13 January 2011 (UTC)[reply]

Aviation transponder interrogation modes just has more detail on them, I take it you don't think that is required? PS, you should also sign in when you make edits otherwise you get recorded as an IP address and it isn't clear who is responding or editing. - Ahunt (talk) 22:25, 13 January 2011 (UTC)[reply]

I had remembered Identification Friend or Foe as being longer that it is. I have added the missing interrogation mode details from Aviation Transponder Interrogation Modes. Plus the article's first reference! Why are there no [citation needed] comments when there are one on every paragraph in SSR and even on idividual entries in tables? Is my log in only valid for Secondary Surveillance Radar? When I go through the log in process with the others it is successful only to find that I am no longer logged in when I return to the article.Monopulse01 (talk) 16:30, 14 January 2011 (UTC)[reply]

I have seen that too, it seems to be a Wikipedia server issue, getting kicked out of sessions. Kind of annoying really! The only reason Aviation Transponder Interrogation Modes isn't full of citation needed tags is because no one has tagged it yet. I would have but I am thinking that it will soon get merged back into SSR. I added the tags to SSR because you are adding lots of text there but no citations. These need to be added or else the text will eventually be removed as "unreferenced". Personally I find it easier to add refs as I add text, rather than go back later and try to figure out where all that text came from. - Ahunt (talk) 16:35, 14 January 2011 (UTC)[reply]

The session problem only seems to occur when using Google Chrome but not Windows IE. You were very quick making changes. I took some time out to have a bite to eat but did not realise that you had made changes so when I came to save my last hour's work it was not accepted. I have been involved in Mode S for over 40 years and much of what I write is from my own knowledge. I am trying to put down a readable story, informative but not over detailed. I then go back and check it and add the necessary references. That is the way I work. I do not think that putting [citation needed] against individual cells in a table is at all justified. If you think that a reference is needed then a single entry to the text referring to the table should be sufficient. Nor do I think that it can be justified to make the same comment against every paragraph regardless of its contents. Since I started the text has more than trebled and the references gone from 6 to 15. I am now away for about 10 days. I would be grateful if you would check the references given to find out if the citation you are demanding is in fact already covered.Monopulse01 (talk) 19:38, 15 January 2011 (UTC)[reply]

If a ref can be found for the whole table then that is fine it can be used in place of the citations for the table contents line-by-line. I think you have run into one of the main problems in writing subject matter off the top of your head, rather than from a specific ref added as a citation as you go along, it makes it very hard to go back and find references retroactively. Despite your kind offer while you are away I really wouldn't be able to figure out where this information came from either so it would be very difficult for me to reference it. The good news is that the tags will work and another editor will probably come along and add refs if he or she has them, or alternatively may remove the text as unsourced. - Ahunt (talk) 22:36, 15 January 2011 (UTC)[reply]

I have more or less completed my input to the document up to the section on Mode S. There are now 27 references not including any others in the other Wikipedia papers referenced. Therefore I have deleted most, but not all, of your [citation needed]. If you want to re-insert any then please justify each one separately. Note that references supporting the statement may not be in the same paragraph.Monopulse01 (talk) 11:10, 28 January 2011 (UTC)[reply]

I have reviewed your changes and most of them look good. Thanks for finding those references, those help a lot. I notice you have once again put reference links in for the home pages of ICAO, RTCA, Eurocae and ARINC. These are not suitable references for the paragraphs that they are in, as they do not support anything in the paragraphs other than that the organizations exist, which, since they all have Wikipedia articles is not in dispute. Adding the home pages as refs is misleading as it makes these paragraphs look referenced when none of the text is supported. Otherwise you have removed a large number of "citation needed tags" without providing the needed refs. Essentially you can't do that - either the refs have to be provided or the challenged text has to be removed. Normally if an editor just removed the tags I would remove the text, but instead I'll replace the tags to show where the refs are still needed. If there aren't any refs or you feel you need to remove the tags again then the text can just be removed as per WP:V. Otherwise there are just a few formatting clean-ups I need to do to meet WP:MOS. I'll do it step by step and the reasoning will be in the edit summaries as usual.- Ahunt (talk) 14:47, 28 January 2011 (UTC)[reply]

I do not understand some of the points you are making about references. Under Standards and Specifications I only seek to list authorities which have a legal influence on SSR. In the ICAO paragraph I specifically mention Annex 10 Vols III and IV. These define practically everything in SSR including Mode S. Those are the citations! What are you expecting? Similarly for the next two paragraphs. They are statements of the roles that these organisations play. What more citations are needed?

Having stated that signals in space are defined in Vol. IV what justification is there for requiring any of the citations in the Interrogation Modes section as the source is given.

Under Deficiencies I give Ref. 7 which lists the problems with the old SSR. I then discuss those problems. Why are they all given a citation needed? Go look at Ref. 7!

I will not go through all the rest but in many cases the needed citation is already in the paragraph.

Please look at the paper again.Monopulse01 (talk) 15:42, 28 January 2011 (UTC)[reply]

My efforts here are to make sure that all your work remains in the article and doesn't get removed, though complete referencing. Wikipedia is fundamentally based, not on truth, but on verifiability as explained in WP:V. Basically all technical information needs to have a footnote added. The tags I have added show where refs are missing. If the refs are already there in the paras, then let's just cite them, shift and add them where needed. For instance, on the subject of the organizations, in the section about RTCA and Eurocae it currently says: "Both organisations frequently work together and produce common documents", but there is no ref cited. Do they actually work together and produce documents? If so where does it say this? In teh section "Interrogation modes" its says "The new mode, Mode S, has different interrogation characteristics. It comprises pulses P1 and P2 from the antenna main beam to ensure that Mode A and C transponders do not reply followed by a long, phase modulated, pulse." Is this accurate, if so why is there no ref cited? All of this requirement for refs is to guard against someone later coming along and just removing the text and saying "no they don't" or "It isn't P1 and P2, but L1 and L2". I'll be watching the article over time but if they did remove that I can't really revert it if there is no ref to support it. Basically any unreferenced text can be removed at any time by anyone. The founder of Wikipedia, Jimmy Wales summed it up as succinctly as anyone: "I can NOT emphasize this enough. There seems to be a terrible bias among some editors that some sort of random speculative "I heard it somewhere" pseudo information is to be tagged with a "needs a cite" tag. Wrong. It should be removed, aggressively, unless it can be sourced. This is true of all information, but it is particularly true of negative information about living persons." So if this text is left in here, tagged of not, if it doesn't have a footnote supporting it it will get removed by someone at some point in time. For one good example of what is needed have a look at the latest article I just created yesterday Titan Tornado. This is so completely referenced that every statement has clear, verifiable and multiple references. This means this text probably won't get challenged and if it does I have the sources right here to double check it and show that the information is verifiable. - Ahunt (talk) 16:05, 28 January 2011 (UTC)[reply]

I have looked at your article. I have also looked at those other Wikipedia articles referenced in Secondary Surveillance Radar. Identification Friend or Foe has only one reference and no citation needed Traffic Collision Avoidance System has nearly all its paragraphs without references but only one citation needed Automatic Dependent Surveillance-Broadcast is a bit in between but again most of the paragraphs are without references are not tagged with citations needed. I think that you very much going over the top with demanding so many citations needed. I would prefer to follow the practice in the other related articles. I am sure of my facts. They are all verifiable by references included in the article. If someone wants to wreck the article by changing P1 and P2 to L1 and L2 then I cannot stop them but I am sure that other knowledgeable people will soon change it back. Please let me follow what seems to be standard practice in the other articles. Monopulse01 (talk) 16:52, 28 January 2011 (UTC)[reply]

That is a Tu quoque argument. Holding up poor-quality articles as examples doesn't diminish Wikipedia policies such as WP:V. The other articles don't currently meet the standard and need reviewing. If you don't want to add the refs that is fine. Other editors will work on the article over time and either add the refs themselves or delete the unreferenced text. - Ahunt (talk) 17:28, 28 January 2011 (UTC)[reply]

I have finish the article as far as it goes, apart from tidying up any clumsy text. I am not bothered about your removing the home pages of ICAO, RTCA, Eurocae and ARINC but I only put them in to satisfy your request for citations. Now that you have repeated the request I am at a lost to know how to respond. What exactly are you expecting? I also have difficulty with the citation requirement at the end of the first paragraph after Interrogation modes. This paper is not about IFF and if the reader wants to read about it then the link is given and that other paper should have the necessary references to validate statements about IFF. I do not think it is the place of this paper to do that. I know that you are concerned about circular references but the IFF and SSR papers are about subjects are not in themselves statements that need verifying. Monopulse01 (talk) 17:05, 30 January 2011 (UTC)[reply]

Thanks for adding those refs, that looks good! I found one existing ref I think will suffice for the ICAO para. As far as the other organizations go all we need are refs that should what is said in those paragraphs is verifiable. For instance one says "ARINC (Aeronautical Radio, Incorporated) is an airline run organisation concerned with the form, fit and function of equipment carried in aircraft. Its main purpose is to ensure competition between manufacturers by specifying the size, power requirements, interfaces and performance of equipment to be located in the equipment bay of the aircraft." We need a ref that shows that is actually the purpose of ARINC. On the "Interrogation modes" section you are quite right, the tag was in the wrong place, that was after just a general statement that didn't need referencing, so I have moved it. - Ahunt (talk) 00:27, 31 January 2011 (UTC)[reply]

New image[edit]

Ahunt. Could you please contact me at michael@monopulse.plus.com. I have a new diagram to replace "Mode S interrogation, short and long" correcting the 30.5µS to 3.5µS and I have lost how to do it. Perhaps you could do it for me. Monopulse01 (talk) 09:45, 11 March 2013 (UTC)[reply]

No problem, just upload it to https://commons.wikimedia.org/wiki/Special:UploadWizard and then if you don't know how to format it on the page leave a note here with the image URL and I'll help you out! - Ahunt (talk) 17:07, 11 March 2013 (UTC)[reply]

Have done. Monopulse01 (talk) 09:27, 12 March 2013 (UTC)[reply]

Great! Let me know if you have any problems getting it onto the page! - Ahunt (talk) 10:42, 12 March 2013 (UTC)[reply]

I would be most grateful if you could move it for me Monopulse01 (talk) 10:53, 12 March 2013 (UTC)[reply]

No problem - can you post the URL on Commons where it is here and I'll put it into Secondary surveillance radar for you. - Ahunt (talk) 12:11, 12 March 2013 (UTC)[reply]

I'm sorry but I am lost. I uploaded the revised diagram and it appears on my User Contributions as entered at 9.42. I cannot find a URL for it. Unless it is File:Mode S interrogation format.jpg Monopulse01 (talk) 15:09, 12 March 2013 (UTC)[reply]

No sweat! I tracked you over on Commons and found it! I substituted it into the article in place of the existing image - hope I got it in the right place! - Ahunt (talk) 15:25, 12 March 2013 (UTC)[reply]

Brilliant. Thank you so much for trouble and patience. Monopulse01 (talk) 15:30, 12 March 2013 (UTC)[reply]

No problem, glad that I could help out! Collaboration works! - Ahunt (talk) 15:33, 12 March 2013 (UTC)[reply]