Penn State Geography
Moderator: James Sloan / David DiBiase
06/11/09/6:45 PM
Page 1
Penn State Geography
Moderator: James Sloan / David DiBiase
June 11, 2009
06:45 pm
James Sloan:This is Jim Sloan.
Jan Van Sickle:Hello Jim.
(Jessica Longshore):Oh hi Jim.
James Sloan:Who -- who do we have with us so far?
Jan Van Sickle:Jan Van Sickle here.
James Sloan:Hi (Jan).
(Jessica Longshore):(Jessica Longshore).
James Sloan:(Jessica) hi.
(Jessica Longshore):Hello.
James Sloan:Are you in 488?
(Jessica Longshore):Yes, I am.
James Sloan:Okay. Because I remember you from a while ago in 484.
(Jessica Longshore):That's right.
James Sloan:Yeah. I'm writing names as we go here.
(Greg Cornet):I'm (Greg Cornet).
James Sloan:Hi (Greg). Are you in 488 now too?
(Greg Cornet):That's correct.
James Sloan:Okay. Right. I remember you too.
(Jessica Longshore):(George), where are you?
(Ben MaCrae):(Ben MaCrae) in 482.
James Sloan:Right, hi (Ben).
Julie Morahan:Julie Morahan in 484.
James Sloan:Hi (Julie).
(Christie Balbino):(Christie Balbino), 484.
James Sloan:Hi (Christie).
(Christie Balbino):Hi.
(Linda Pastor):(Linda Pastor) 484.
James Sloan:Great.
(Joshua Brown):(Joshua Brown) 482.
James Sloan:Hi (Joshua).
(Joshua Brown):Hi.
James Sloan:(Julie), what was your last name again. I'm sorry.
Julie Morahan:It's Morahan. M-O-R-A-H-A-N.
James Sloan:Okay. Great. What we usually do and I say usually even though this is the first time I have hosted one of this phone conferences is wait a few minutes after the, you know, advertised 5 o'clock start date just for people to -- to call in. So my -- my computer clock says two minutes after five. So we will wait two or three more minutes, I guess.
Man:Sounds like a good idea.
Woman:Okay.
James Sloan:Okay.
Julie Morahan:I wish I was where you were at then it would be 5 o'clock for me. At Colorado it's only three. So my workday is not over yet.
James Sloan:Now, who is this?
Julie Morahan:Julie.
James Sloan:Julie. Okay.
(Jessica Longshore):I'm right there with you in South Dakota.
James Sloan:Well, that's where (Jan) is too. Right (Jan)?
Jan Van Sickle:I'm in Colorado?
James Sloan:Colorado, yes?
Jan Van Sickle:Yeah.
(Jessica Longshore):What part of Colorado?
Jan Van Sickle:Denver.
(Jessica Longshore):Me too. I'm in Lakewood.
Jan Van Sickle:Oh well, welcome.
David DiBiase:And this is David DiBiase. I'm in (unintelligible) standard calling in from (unintelligible). Innocent, uh?
Man:Well, that's -- well, maybe not.
(Ryan):This is (Ryan Epinstil) from 482.
James Sloan:Hi (Ryan).
(Ryan):How's it going?
James Sloan:And you are in State College. So you didn’t have to call very far.
(Ryan):No, not at all. (Unintelligible). I actually have to step out for few minutes but I'll just hang on.
James Sloan:Okay. Hey David?
David DiBiase:Sir.
James Sloan:When I hear the little beep, does that mean a new person will come in or has left? That sounds like a new arrival. Oh, you all hear that too, okay. So far folks if you are -- if you just joined us, we are -- I'm sort of taking roll and we haven’t really officially started yet. We are giving people a few minutes after the 5 o'clock start time to -- to make the connection. So if anybody hasn’t chimed in, go ahead.
(Jackie Jyle):This is (Jackie Jyle) from 482.
James Sloan:Hi (Jackie).
(George):Hi this is (George) from 488.
James Sloan:Good, good, George.
(Eric Taflot):This is (Eric Taflot) from 484.
James Sloan:(Eric).
(Susan Filament):(Susan Filament) from 488.
James Sloan:Hi (Susan), I remember you from 484.
(Susan Filament):Yeah. (Unintelligible).
James Sloan:Good for you. That is -- somebody else just joined us? Well, I -- I show five after. So let's -- let's -- I'm going to attempt assuming the buttons I pushed are correct to record this. So keep that in mind everybody. Because there are several people that expressed the desire to join but couldn’t make at this time and we are hoping that they could get some feedback after the fact. So I like to welcome everybody that has called in to this teleconference. The featured guest is Jan Van Sickle. He is the instructor for our -- our Geography 497i soon to be Geography 862. GPS and GNSS for the global special professional and he is also the author of among other books, the third edition now of GPS for land surveyors and basic GIS coordinates and so what we are here today for is to allow folks to ask -- or to give Jan a shameless opportunity to plug his cores and for you folks to ask him about his course and then the other thing, David might be stealing his (unintelligible) here quickly but what prompted the teleconference was David letting us know about the general accounting offices report of the state of -- of the space segment of the GPS system. So I guess with -- let's see. Jan, do you want to speak to the -- to the GEO report to start of?
Jan Van Sickle:I'll be happy to. First of all, let me see that I really appreciate all of the help in setting up this conference call Jim and thank you everyone for taking the time to come in and -- and talk about this. Yes, GEO report has certainly stirred up a lot of concerns. Interestingly, I was at a conference here just a few days ago here in -- at this park and the subject came up there and this was concerning GPS for a pipeline. So there's a lot of -- a lot of concern. The article that I think were probably talking about that -- that was most visible although there was more and certainly more than one was GPS at risk in GPS world. Was a periodical GPS world but boy I'll tell you, there certainly was a lot of coverage in Fox News, CBS News, Good morning Silicon Valley. That was my favorite. It -- it said that the quote was the GPS says I'm in your driveway but the car is sinking. All you see is (unintelligible). So it -- it stirred up a lot of concerns and any -- if -- if folks have read the article, if there are any questions or where you would -- because there is a whole lot of things to talk about. Does anybody have any specific questions if they read article or others concerning that?
Well, if not, I'll just go into some -- some ideas. One of the things that has been brought up about the article was that as you point it out, that is focused on the space segment. 24 satellites are required for 24-hour worldwide coverage in the constellation of GPS and we currently have actually 31 satellites on orbit. Seven more than are required. One of them is just still in the check out phase and then in addition to that, it's not widely known if there was three other GPS residual satellites in orbit. These were the older spacecraft that can be brought back to life if need be.
So it certainly isn't true that GPS constellation is going to be somehow switched off or something. That -- that is certainly not the case. Most of the predictions if we call them that from GEO report and also from the follow up congressional hearing based on multicolor projections or simulations of what could happen if the satellites basically were out or go off line and the -- the fear is that there is -- that the reliability of the constellation will drop below the 95% level early -- no one knows exactly but somewhere in 2010 or thereabout and then the below 95% reliability until about that 2015 and this is kind of a worst case scenario but that's the concern.
Is there any other aspect of it that I could address?
Julie Morahan:This is Julie Morahan --
(Jessica Longshore):I would like to at least just make a comment in regards to this. My name is (Jessica) and I currently work for the Department of Defense. I can't help after I read the article to stop and think, is this another Y2K type of scare in order to encounter Federal funds for a space program that has really had a lot of Federal funding cost and especially in these economic times. Can you address exactly the severity and the impact of -- of the situation with GPS because like I said as -- as myself. I'm -- not really necessarily paranoid but I would like to know maybe a little bit of the validity of the impact that they are talking here.
Jan Van Sickle:That's a good question, (Jessica) and let me say first that I -- I share your skepticism. I think that it's only prudent to say that part of the concern here is kind of inside baseball. In other words, the Department of Defense certainly is the primary agency concerning GPS although it is -- it is actually being administered by -- by more than one department but DOD is certainly the number one and there is a -- there have been cuts in GPS. For example just to give a sense of that to everyone that might not be familiar with it for a very long time as GPS future was to defining program called GPS Three and it -- it was cut back rather substantially some years ago and this was quiet a blow to -- to the plan to really roll out the most up to date space segment and that has had somewhat of a ripple effect in terms of the launching of satellites and while it has -- and of course, on top of that the space shuttle disaster and other things had a tendency to move things back and this has been part I'm sure. I think it's fair to say. This has been part of the hoo ha ha here, internal within the government to try to find a way to focus attention on the needs of this obviously very vital utility. I don’t -- it -- it's awfully difficult to come up with exactly the right words to say that well, that's true. There really is a concern but not and that's what I'm trying to say. Not a -- the sky is falling kind of concern. In other words, it's somehow don’t buy a GPS because it won't work anymore. I mean that kind of thing. That is certainly not true. The worst-case scenario that I have been able to determine from all my reading on the subject has been that we might fall below 24 satellites for a period and that is quiet unlikely. In other words as I said what they are saying is that 95% chance -- 95% reliability we might go down as to 80% reliability but for example some of the things that are standing in the way of -- of that as I said, we've got 31 satellites now operating in orbit. Another Block 2Rs is scheduled for launch in August, late this summer and 12 more block 2Fs are coming on line. By the way what I mean by Block 2Rs and Block 2Fs is these are the advanced satellites, are coming on line beginning next year. So these satellites are going to continue to be launched. It is very unlikely that we are going to drop below 24 but interestingly, one of the things in the article and in other things that have come out that might be kind of escaping notice is that really probably the most concerning thing from the Department of Defenses point of view is that the hardware in the hands of the users and this -- this -- these are the military users is lagging behind the signals that are available from space. There is not the M code which is available, the new Military code which is available on the satellites that are going up now. The hardware isn't there to receive it and this is one of the biggest concerns from a DOD standpoint but interestingly from a civilian standpoint the M Code isn't of no use to us in anyway. So the civilians user segment has been very good about keeping up with the latest technology in terms of -- of being able to receive whatever signals are currently available. So I guess my point, my answer to your question is I agree with you that there is a certain amount of just trying to focus attention. There is a problem but actually it's much less of a problem to civilian users than it is to military users.
(Jessica Longshore):Okay, thank you.
Jan Van Sickle:You are very welcome and anybody else that I can address to these -- these questions like for example, there was a mention in the article of Loran that I think is an interesting side bar. Loran is a radar system that has for some time been touted as a back up to the GPS system. And it was to be funded in a program called eLoran and then recently the Obama administration cut the funds for it under the -- the justification that it was an old technology system that needed to be -- that that shouldn’t be funded anymore. Well, the part I believe of the -- of what's going on here is that the eLoran is needed to back up GPS and I think part of the reason that this has happened, this -- this scare has happened is to get the funding restored to eLoran and as a matter of fact it has been restored. It has been -- now, they have reversed their decision and it is now going to be fun. So this is a good thing.
(Jessica Longshore):There's question about the backward compatibility. The article touched a little bit on it and I come from a software background. So we are always talking about what’s our level of service commitment and what's backward compatibility. What -- what sort of (unintelligible) do we have there and the article just briefly touched on the launching of the new satellites may cause backward compatibility issues with all the receivers. So is there any kind of standards in regards to the satellite that the folks that manufacture the GPS receivers expect or depend on.
Jan Van Sickle:Good question and yes, the answer is yes. Now, again I need to make a distinction between the military receivers and the civilian receivers and I'm presuming that we are almost exclusively interested in the civilian receivers. Everything that I have seen has indicated that the civilian receiver manufacturers have a very keen interest in making sure that there receivers will be as you put it back were compatible or in other words, no matter what new signals became available that the receiver you buy today will function five years from now that kind of -- that kind of ideas and so I have -- I have seen no reason to be concerned -- for example, just to give -- just a brief example the most hand held mapping grade receivers use what is known as the CA code, the Course Acquisition Code on the L1 carrier.
Now there is a good deal of discussion about having a new code on L2 which is called L2C and also adding another code an L1 which will be called L1C however everything that I have seen has said that even if L1C is added, the old Course Acquisition code will continue to be broadcast. So that if you have a hand held receiver - mapping grade receiver it will continue to work. Now I think what you might be referring to about the backward compatibility is perhaps you are talking about the gentleman from OnStar that was - that was making some recommendation Chet Huber. Is that what you were thinking of?
(Jessica Longshore):Yeah and I - I can't find it in the article now but I thought I read something about renumbering the slots would cause some problems that some receivers couldn’t deal with more than thirty satellites.
Jan Van Sickle:Okay, here is what - here is what I think is the statements. Chet Huber from OnStar which is of course the General Motors and then as they say in the article the largest single group of civilian GPS users. He said, first we must address to health of the current constellation and then second as the GPS system is modernized, it is imperative that the US government formally commit to preserving the L1 CA signal and to ensure backward compatibility for legacy applications with no lost performance from current levels. I think that’s - that's what you are thinking of and he also said on his third recommendation. This is the very end of the article that we commit to maintaining the current PRN which is pseudorandom noise code for the primary orbital slots as satellites on those slots are replaced. Legacy hardware is not capable of being expanded to accommodate more than 32 slots. So numbering above 32 will likely effect performance of legacy applications.
(Jessica Longshore):Yeah, that was the part that caught my attention.
Jan Van Sickle:Well, I must say I don't entirely agree with Mr. Huber and the reason that I say that is there is going to be a new navigation code called C-Nav, that's going to be quite a substantial upgrade from the current navigation code and let me just explain what - basically what I mean by that. When you turn on a receiver, if you are on a cold start you may have noticed that your - that your initial - your initial start, you have to really wait quite a bit of time before you - before you start acquiring satellites.
Now after you have done that the first time, you need to turn it off and turn it back on again and it -- it requires satellites pretty rapidly. But one of the reasons that it takes some time is because your receiver has to update its navigation code in some of the components in that code like the OMNEX file and that comes directly from the satellites. The navigation file is going to be upgraded such that there is going to be space in that - in that navigation code to do things like tell your receiver, all right there is a - a new satellite in slot 33. You can address that as if it were in slot 16. So the slots where you will be able to handle some of that. However, currently there is no reason at all that it can't be assured that the CA code will be maintained and the 32 slots will also be maintained. I think what Mr. Huber is asking for is some kind of a formal statement that will assure that there will be no changes there. I can understand why he would - why he would want that but I don't think that this means that the most GPS receivers are going to have a problem. I just - I just don't see why that would occur. There is too much flexibility in the system especially flexibility that's going to be built in the new satellites with the new signals. I must say that overall as far as reading this article and I went through it quite carefully. There was very little that I felt like was a real - a real alarm. I don't think there is anything that would - that would be very concerning in the long term. However I don't want to say that somehow I know that we will never drop below 24 satellites. I certainly don't know that but even if we did, I don't see how that would cause substantial degradation in the - in the kind of GPS coverage that people have come to expect.