Kerry.

Even before the III's fly the Block II-M's (balance of the stored II-R's modified ~12 ready to go) and the next generation before the next next generation III's the Block IIF's (originally 33 planned but all might not be built) will give a handheld GPS user less than 1.5m accuracy, but this comes at the price of a new receiver. However current receivers will at least be backward compatible. Cheers, Kerry. I never get lost everybody keeps telling me where to go

In Alaska, It does and it doesn't just depends on where in Alaska one is. Much of the WAAS on board testing, which started back in 1998 was done based on Juneau airport. It's an interesting airport and picked for some obvious reasons if that's the one with that bloody great mountain at one end. 61N, 149W gives POR at about 16 degrees, which isn't brillant but in theory should work totally barring all obstructions. Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by PDOP's:''How many GPS satellites are WAAS enabled?'' None but don't the two WAAS satellites also transmit the same signals as regular NavStar(GPS) satellites in addition to the WAAS corrections? Apart from the WAAS corrections being transmitted on the same freq as GPS L1 they (the WAAS Geo satellites) do also have the capability to act as ranging satellites similar to GPS satellites but I'm not sure if it would require specific receivers and/or software to make use of the WAAS message type #9 (Geo ranging data). Due to some timing issues between WAAS & GPS the WAAS geo satellite ranging errors are quite large compared to GPS standards/capabilities. But then there's not to many recreational type receivers that can make full use of all WAAS capabilities, integrity monitoring and error reporting anyway. Cheers, Kerry. I never get lost everybody keeps telling me where to go

GPS and WAAS are effectively 2 DIFFERENT operations, just that WAAS relies on signals from GPS. WAAS is unable to operate without GPS but do not have any control over GPS, where as the custodians (US DoD) of GPS have the ability to terminate WAAS in times of emergency. WAAS operations has no control of any GPS satellite and as you mention WAAS uses 2 satellites (commercial communication satellites) in stationary orbit over the equator. WAAS badly (critically) needs a third as there is simply no redundancy with WAAS what so ever at this point in time. Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by GeckoGeek:Now I'll have to go back and find out what kind of orbit the GPS sats are in. I thought the pattern was to cover all of the earth fairly well. I'd have thought the polar reagion would have been well covered since "the red menance" was still much of a design consideration and navigating near the poles is a real pain. GPS has 6 orbital planes inclined at 55 degrees with room for 5 satellites (slots) in each plane. GPS sats are Geo-centric orbits earth-centred and are basically circular. GPS satellite coverage if one was at either of the poles would look like this everybody keeps telling me where to go

GeckoGeek, ok I understand your comments now. I suppose "WAAS geo's", which is a term commonly used for them would be better termed "WAAS Geo-stationary" as opposed to the GPS sats being Geo-centric. For this reason as they don't move (the WAAS geo stationary satellites that is) and probably similar to GOT GPS's comment if one doesn't have a WAAS signal due to low horizon, obstructions etc then no amount of waiting will ever change that condition. Probably said this many times before but for best possible reception from a handheld then one should actually face the direction of the equator. With straight GPS this is important as there's no satellites over the poles and secondardly with WAAS it's even more important (to face the actual direction of the WAAS geo) that there's nothing between the antenna and the direction of the WAAS Geo-stationary sat/s. Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by EraSeek:... WAAS is a system of satillites and ground stations that analize things such as ionosphere activity which can delay your signal from the sats and throw your position off. Data is sent down from the sats, analized and sent back to the sats and then to your GPS to correct for these errors for the area that you are in on the modeled grid .... That reads to me (impression) that the WAAS "sats" (themselves) do the analyzing but the WAAS geo's are primarily simply a communication/re-broadcast satellite, even thou the WAAS geo's (inmarsats) can be enabled to act as additional pseudo "GPS sats". Maybe if the 2 different types of sats were specifically tagged it would make for a better impression. Basically all the WAAS geo's do is transmit the corrections as for there to be corrections the user must have GPS satellites in view that are also being tracked by 4 WAAS ground stations. "....Data is sent down from the sats, analized and sent back to the sats and then to your GPS to correct.... " Data is received from the GPS sats (by the ground stations), analyzed and corrections sent back via the WAAS geo's then to your GPS to correct etc Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by GeckoGeek: quote:Originally posted by Kerry:The equator? well it does really as geo satellites, which is what WAAS satellites are are basically directly over the equator. I had to double-check your statement. WAAS signals are carried on geo-stationary satellites. (The GPS sats are NOT geo-stationary.) Geo-stationary units are always over the equator since there's no other way to make them orbit the earth and make them appear stationary. It should be noted that WAAS was primary made for airline navigation. As such being able to “see” the equator isn’t usually a problem. GeckoGeek, I've read that and read it several times more looking for whatever issue you are trying to outline or "double-check". But going back to the previous overall post the comments were in relation to this thinking that one must have a clear view to the EAST and/or WEST, which is simply not the case. Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by volks_ev71:Equator has nothing to do with getting WAAS. Make sure your east and west sky are pretty clear near the horizon, i.e. no mountains or trees obstructing the view. There are two WAAS satellites, one over the west coast and one over the east. The equator? well it does really as geo satellites, which is what WAAS satellites are are basically directly over the equator. So east or west would only be (really) relevent if one was actually at equator latitudes but then one would be outside the WAAS correction area anyway. The further one moves north (away from the equator) then the WAAS satellites are more South-east (actually more south from the US east coast) and south-west as one is over the east coast of Brazil and the other in the western pacific. Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by GeckoGeek:Does a Geko 201 accept more then just WAAS? I've gotten the "D" indicator in Hawaii and in Japan. So either I'm picking up something else or WAAS covers a lot more then just CONSUS. The satellite signal coverage/footprint does but the corrections do not. I believe the latest software version corrects this little oversight in the software as now that ENGOS is in test mode if one is not within in the actual correction zone then the unit will not use WAAS/EGNOS etc. The problem was if one was outside the correction zone one could receive the geo sats but WAAS reception actually destroyed accuracy. Cheers, Kerry. I never get lost everybody keeps telling me where to go [This message was edited by Kerry on August 31, 2003 at 10:20 PM.]

Merman, for sure back then one would have had to be more than your typical user, especially to be using "loaned" equipment as in 1985 using this "loaned type" of equipment in that type of place would have certainly been for some "specific" purposes especially considering GPS was only declassified in 1984. That receiver would have certainly been one of the very few and very first ever made. But serious question as to what part of the day there was useable signals as in 1985 things were extremely trying without being in the jungle, clearing or no clearing. It's not as if one could have simply whipped a receiver out and obtained a position just any old time. Magellan did release the world's first handheld GPSr (Magellan nav 1000) in 1989, and I would presume that is probably what was being offered as the first commercial handheld. Things did really get a kick along in 1989 with 7 satellites launched within 12 months but even during the 1990 Gulf war the then constellation of the time still didn't (couldn't) provide full coverage (in the desert) and that was even with deliberate and purposeful manipulation of the 16 Sats at the start of the war. Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by The Merman:When? 1985 (believe it or not) .... Then you must have had a lot of spare time? What part of a day was actually workable? I suppose that would depend on if that was early 1985 or late (Nov/Dec) 1985. There was one more sat available for the last 2 months of 1985. But considering they were 10 Block I sats launched between Feb 22, 1978 and Oct 9, 1985 with SVN7 lost on launch (Dec 18, 1981) and no further launches until Feb 14, 1989 being the first of the Block II's and also with SVN 1, SVN2 & SVN5 failing well before 1985 then that left 7 operational satellites in 1985. Now that's a pretty big ask from only 7 Block I satellites in the jungle. Coverage a 7 satellite constellation today in the middle of Brazil and this is without the Jungle. Throw the jungle over the top of that and even those periods of barely 3 MAX satellites would vanish and the already completely shot DOP's would go completely thru the roof. everybody keeps telling me where to go [This message was edited by Kerry on August 28, 2003 at 06:57 PM.]

Under the Units setup there should be a UTM/UPS Position Format option. Input the UTM coords direct (also requires the zone), the conversion to other grid formats will be automatic to what ever Position Format you select. What bother converting them when you want to input them anyway. Cheers, Kerry. I never get lost everybody keeps telling me where to go

The WAAS equiv that will cover Europe (including England) is EGNOS and is currently transmitting a test signal, which effectively gives no guarantee to the availability or reliability of the signals/service. EGNOS will supposedly be operational sometime around April 2004. Until then while trasmitting message type 0 it's a use at ones own risk service. Cheers, Kerry. I never get lost everybody keeps telling me where to go

Yes, basically a contradiction in terms. Som what does "but it's not too accurate" actually mean in quantitative terms and just what accuracy are to expecting/hoping to get anyway? Why would you like "Position Averaging", any particular reason? Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by Neo_Geo:How accurate do you want? There are http://mightygps.com/geoxt.html that are accurate to within a meter of the location (under ideal conditions). Within a meter? not in a stand-alone mode they aren't, that'll require extra arms and legs Cheers, Kerry. I never get lost everybody keeps telling me where to go

Simply based on coordinates and time then one really wouldn't know which way the GPS was actually pointing. For all it cares a GPS can be held backwards, sideways etc and the route information (based on simple waypoints) would be the same. However if one assumed the GPS was (allways)pointing "along" the line of the route then it would basically be the forward bearing, which could be computed from point to point to point etc along the route. Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by volks_ev71:I get flawless coverage under trees with my V. Flawless cover! well there's trees and then there's trees. For every tree that one "might" get "reasonable" reception in/under there's a thousand more that will knock that thinking for six. In simple terms there's no receiver made that will hold a full lock at all times in dense tree cover. GPS receivers simply don't like trees but if someone is going to claim perfect reception in so called trees then at least try and qualify the trees, otherwise stating that brand XX is perfect in simply "trees" says bugga all and is rather (very) misleading. Cheers, Kerry. I never get lost everybody keeps telling me where to go

Loran-C is still operational (unfortuneately some will say) and there is really no comparison (as in looking the same) between Loran TD's and Lat/Long coordinates (GPS as such). Some GPS receivers can use TD's and even convert these to Lat/long (software is also available to do this) but much can be lost in this conversion and in reality the absolute accuracy of Loran is rather poor compared to GPS. Based on converting Loran TD's to lat/Long don't be disappointed if you don't find what you are hopefully looking for. Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Mathematical name actually Trilateration was a common geodetic survey principle (different to Triangulation) long before GPS ever existed. That was after they discovered how to measure long lines as compared to the older less accurate method of measuring angles. Trilateration is the closest thing in normal terms that fits how a GPS receiver computes a position. Some describe it more as a "Resection by Distance" so how about we call it Trilateration. Cheers, Kerry. I never get lost everybody keeps telling me where to go

Sometimes it can depend on the soil type, which can dictate the type of mark placed. Concreted marks are no good in soil types that have a habit of moving and with some soil types it's the top surface layer that does much of the moving. Deep driven marks are used in bad soil types where surface/ground movement is expected so the marks are driven until refusal and sometimes this can be many many many feet. Just keep screwing on rods and drive them until they won't drive anymore (refusal). Mostly driven below surface level as the surface generally can have the tendancy to move/bend/shift things just enough to be critical. However these types of marks driven to refusal (especially at depth) are generally more of a level mark so horizontal movement is not as critical as vertical movement. These types of marks in Oz are mainly used in "Black soil" country, which has a very bad habit of movement. Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by SpongeRob:I know the UNIT does not have that ability, but from what I have read the WAAS base stations DO have the ability to transmit to the satellite. Does anyone have any articles to back this up? The WAAS ground stations do communicate with/to the WAAS geo satellites (onlt 2 of them) from which the corrections are re-broadcast to the users. The WAAS geo's also have other capabilities in that they can act as another look-a-like reference satellite however corrections and manipulation of the GPS satellites for things like timing, ephermeris, maintainence etc are the sole responsibility of the GPS Master Control Station at Schriver and the remote monitor stations, which has nothing to do with WAAS or DGPS or any other of the augmentation systems that rely on GPS to function. WAAS and DGPS services, ground stations have no access to the GPS satellites (apart from using the signals like all users), which are steered time wise from Schriver in conjunction with US Naval Observatery (USNO). Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by Waterboy With Wife (www):It _may_ be a format error. In that sense it certainly may be a format error if all things fall into place if the unit was in fact configured to decimal degrees. Still like to know what GPS it was. Cheers, Kerry. I never get lost everybody keeps telling me where to go

10-20 miles isn't a normal datum issue or a format issue and certainly nothing to do with magnetic or true north settings. Especially if ALL are similarily off by that amount then it's something that is common and not simply stuffed up coordinates. What GPS is this? Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by SpongeRob:.... The only entry I could find was where the WAAS and DGPS send messages back to the satalites to correct signal drift by adjusting the clock on the offending satellite. That made sense. WAAS and DGPS have no capability in communicating back with any of the satellites. That description could mean one of many things but one could assume it had something to do with the sequence of signal generated internally in the receiver that is similar to and matched against the incoming signal, which allows the receiver to determine time and hence the pseudo-ranges. Cheers, Kerry. Cheers, Kerry. I never get lost everybody keeps telling me where to go