flying dog Posted July 11, 2010 Share Posted July 11, 2010 Folks, Situation is this: I have a text file with "squillions" of points which I want to become WAYPOINTS for the GPS. I know how to do that, but there is no DATUM declared in the file. I don't think it is WSG84 - the default for flying. How can I find out/work out what the datum is before importing them to the GPS? Link to comment Share on other sites More sharing options...
Guest basscheffers Posted July 11, 2010 Share Posted July 11, 2010 post a few lines from the file for us to look at? Link to comment Share on other sites More sharing options...
CraigRat Posted July 11, 2010 Share Posted July 11, 2010 What format is the file (CSV, GPX etc)? Usually it is implied that it's WGS84 unless specified. Can you post the file somewhere or email it to me? Link to comment Share on other sites More sharing options...
flying dog Posted July 11, 2010 Author Share Posted July 11, 2010 Here is a small sample: 1746,AARE - 27.3637, 153.25935434.500, 0, 1, 4, 0,AARE 2806,AASS - 34.5550, 138.322935434.500, 0, 1, 4, 0,AASS 3578,ABAY - 38.4523, 143.40235434.500, 0, 1, 4, 0,ABAY 59,ABCH - 33.2853, 151.255235434.500, 0, 1, 4, 0,ABCH 1751,ABCK - 27.2047, 152.575635434.500, 0, 1, 4, 0,ABCK 23,ABDN - 32.1028, 150.531335434.500, 0, 1, 4, 0,ABDN 3569,ABEE - 38.1554, 146.2135434.500, 0, 1, 4, 0,ABEE 1744,ABER - 25.80, 151.74535434.500, 0, 1, 4, 0,ABER 3570,ABES - 38.2126, 146.62935434.500, 0, 1, 4, 0,ABES 24,ABFL - 30.1531, 152.1135434.500, 0, 1, 4, 0,ABFL 25,ABMN - 32.4839, 151.255635434.500, 0, 1, 4, 0,ABMN 1752,ABON - 27.2536, 153.3335434.500, 0, 1, 4, 0,ABON 3591,ABRY - 36.1537, 142.145335434.500, 0, 1, 4, 0,ABRY Ignore the first number. I will change that to X for waypoint. But the other numbers: Well, guess what they are. Link to comment Share on other sites More sharing options...
Guest basscheffers Posted July 11, 2010 Share Posted July 11, 2010 What kind of waypoints are these? Obviously not airfields, VFR or IFR ones. Knowing that might give us a clue about what the numbers mean. But on the surface, they look like normal decimal notation coordinates. They just show up in the middle of nowhere. Do you know the WGS84 location of any of these, so we can compare? Link to comment Share on other sites More sharing options...
flying dog Posted July 11, 2010 Author Share Posted July 11, 2010 (Gee you are up early) I don't know where they are as I simply picked the first few of the BIG list. I'd prefere not to say what they are, other than addresses. I can get one or two which I know in WSG84 and post the two for comparison. 51,ASHF - 33.5317, 151.73035434.500, 0, 1, 4, 0,ASHF Compared to WSG84 being: S33 53.281 E151 07.482 294,BURD - 33.5240, 151.61735434.500, 0, 1, 4, 0,BURD Compared to WSG84 being: S33 52.669 E151 06.259 Alas even the WSG ones are APPROXIMATE but close enough. When I load the ones I give, they are "close" but not close enough. Link to comment Share on other sites More sharing options...
flying dog Posted July 11, 2010 Author Share Posted July 11, 2010 Here is a screen grab with the two points. I've taken the liberty of adding a "leading zero" to the number as it doesn't work otherwise. But as you may see, it is a LONG WAY from where it really is. (Oh the grab doesn't show the hand/cursor, so trust me where the red arrow is pointing is where I get the LAT/LONG shown at the bottom of the screen.) Link to comment Share on other sites More sharing options...
Guest basscheffers Posted July 11, 2010 Share Posted July 11, 2010 Ah, so that's what they are! :) You'd think they might use GDA instead of WGS84, but that would put them off by metres instead of many miles. Maybe a bad conversion from one file format to another? Obviously, decimal -33.53 doesn't become S33 53... I'll keep scratching my head on it. Bas. Link to comment Share on other sites More sharing options...
flying dog Posted July 12, 2010 Author Share Posted July 12, 2010 I tried Aus Geo xx but neither worked. Alas I can't get in touch with whom ever made the list - that would be TOO easy. What I also remember when I tried a few waypoints/co-ords, there was no detectable consistancy with them. The one I showed was a few hundred meters WNW. Another one was in a different direction. MAYBE the whole set if numbers are wrong - who knows? Not me. Manually checking them all would take an eternity - as there are probably a few hundred points, and that sort of thing is exactly for what computers are designed. Processing data and doing repetative functions. Link to comment Share on other sites More sharing options...
CraigRat Posted July 12, 2010 Share Posted July 12, 2010 You should not be adding a leading 0 to anything as it SHOULD be in decimal Degree format (ddd.dddddd) You need to set your map program up to use it (from that screenshot I can see Mapsource is using ddd mm.mmmm format) Using this I have ASHF out in the Tasman Sea not sure if this is correct as google is returning nothing of substance for 'ASHF' The 5434.500 on the end of the Longitude looks like it's a separate data value and there's a comma missing. Is it possible for you to send me the file so I can have a better look? If you can send it to [email protected] I can pull it apart better and get an understanding of what all thwe data SHOULD be doing and correct any obvious error Link to comment Share on other sites More sharing options...
AlanB Posted July 12, 2010 Share Posted July 12, 2010 FlyingDog, I think it's a formatting issue. If you look at the first set of coords from the comparison the lat appears to be deg min sec. ie -33.5317 or -33 deg 53 min 17 sec. This is -33 deg 53.283 min in dd mm.mm This is close to the comparison lat of -33 53.281. The long does appear to have a leading 0 missing. I remember seeing this format when trying to convert some coordinates awhile back using some sharewhere program. It also runs into the next variable without a delineator. The Lon part is 151.730, adding the leading "0" makes it 151.0730 ie 151 deg 07 min 30 sec or 151 07.5 min. This is also close to the comparison lon dd mm.mm of 151 07.482. I agree with CraigRat that the remaining part "35434.500" is another variable, maybe a numeric date format or it may even be two variables without another delineator?? There is still 30 ish meteres between the coords and the WGS84 ones you compared them with...is this close enough? Hope this helps. Al Link to comment Share on other sites More sharing options...
CraigRat Posted July 12, 2010 Share Posted July 12, 2010 [edit: disregard, just re-read the above and concur] not too sure how the data ended up in the format they have though....quite odd! Link to comment Share on other sites More sharing options...
flying dog Posted July 12, 2010 Author Share Posted July 12, 2010 Alan, Craig, Yeah, most confusing. I'm at work now, so can't do anything. I was thinking of dd.dddd format and didn't try it. But it seems you two beat me to it. I shall try to send you the file soon Craig, it is just I don't know when - probably this evening. Link to comment Share on other sites More sharing options...
Gibbo Posted July 12, 2010 Share Posted July 12, 2010 The accuracy I suspect is caused by the resolution of the coordinates.. Four decimal places will only get you to within about 500m. If you have a look at the ERSA points they will always be out by a fraction as they do not provide the accuracy. Some of the IFR GPS plates may be a better soultion if you need some accuracy. Have a look at Melbourne airports coordinates. Gibbo Link to comment Share on other sites More sharing options...
flying dog Posted July 13, 2010 Author Share Posted July 13, 2010 I got lucky and have time to scratch myself. Here is a slightly bigger samle of the data. Oh, why the leading 0 was missing - or is suspected to be missing - is that that data was a concatination of data from excel and so 07 is shown as 7 and so when it is concatinated, you lose the leading 0. Anyway, the full list is probalby 500+ enteries. I don't/can't expect anyone to do it all for me, but here is a somewhat larger sample. Please understand I don't want to divulge too much on what it is, suffice to say the co-oirdinates should be on land, and are "plant" locations. BSMP 148.939 -32.7275 ABMN 151.432 -32.8108 BLDY 148.499 -32.8664 ALBT 147.504 -32.3597 APPN 150.789 -34.1928 ALPK 150.795 -34.5614 ARAL 149.812 -35.6508 AUST 150.806 -33.9269 ALTN 148.227 -32.8942 ATRE 148.393 -31.4908 ALDS 149.481 -30.8386 AVAL 151.328 -33.6383 BANN 149.469 -34.5814 BDNE 149.067 -30.9489 ABCH 151.434 -33.4728 BRGO 150.576 -34.2908 ASHF 151.125 -33.8878 BRRR 145.287 -31.4019 BNTN 151.911 -31.9728 ABDN 150.89 -32.1642 BALG 151.263 -33.7936 BDRN 148.64 -31.8747 BRMI 150.468 -32.3875 BRTN 149.132 -35.3075 ANBO 149.42 -35.765 ANNA 152.069 -32.7692 BLAK 151.114 -33.9825 BLKY 148.973 -34.6739 BLAX 150.717 -33.4944 BLAY 149.256 -33.5331 BICK 148.765 -33.7153 BNNA 149.741 -31.6658 BOTA 151.202 -33.9461 BELT 151.661 -33.0364 BHST 148.624 -32.1814 BROK 151.106 -32.7492 BNYH 152.218 -32.1633 BELU 148.553 -33.615 BKHM 148.639 -34.8133 BLRO 151.623 -32.9547 BUDT 148.665 -33.4228 BUGL 148.091 -31.9014 BWNG 148.818 -34.7667 BOWL 150.419 -34.4781 BMGA 148.484 -34.8061 BECO 151.83 -32.0678 BEMA 150.319 -34.4994 BRAL 151.959 -32.4728 BNRE 148.973 -33.2475 BREW 149.761 -33.5081 BENI 148.713 -32.2203 BWIN 151.596 -32.8356 BROO 151.227 -33.5489 BUDH 148.212 -32.0564 BUPT 151.541 -33.2283 BRWD 149.799 -35.4419 BMBG 150.441 -33.5364 BLVE 151.436 -33.3492 BKPK 150.787 -33.6414 BAUL 151.001 -33.7694 BUEK 149.23 -35.5167 BRWG 150.515 -34.5933 BRXN 151.351 -32.6586 BBOY 150.666 -31.9061 BDBE 149.487 -34.7908 BRNG 148.801 -31.8131 BWLY 150.39 -35.5081 BUKN 147.464 -30.8983 BOCE 149.723 -32.8336 BODA 150.05 -36.0858 BNGE 147.804 -33.1064 BRUP 147.865 -32.8353 BNDH 148.292 -33.9089 BULA 152.208 -32.4133 BULG 151.018 -32.6522 BGRM 148.065 -32.6086 BOND 151.273 -33.8883 BRBG 148.863 -31.6664 BGML 148.293 -33.0236 BLCK 152.295 -31.9506 BNJK 148.619 -34.9817 BURD 151.104 -33.8781 BATE 150.185 -35.7144 BATH 149.581 -33.4167 BALA 149.622 -35.5889 BEDG 147.701 -33.3606 BERY 150.692 -34.7742 BLMR 148.899 -32.195 BVDE 149.114 -34.5325 BALM 151.178 -33.8567 BRWA 149.468 -32.1175 BDLA 148.732 -35.395 BANR 147.096 -33.2789 BDGV 151.716 -32.2978 BIAL 149.245 -34.5986 BDDN 148.799 -31.5628 BANK 151.032 -33.9167 BLKH 150.286 -33.6356 BLAC 150.908 -33.7706 Link to comment Share on other sites More sharing options...
Spriteah Posted July 17, 2010 Share Posted July 17, 2010 Plant as in crops? hmmmm.\\\\ :big_grin: Link to comment Share on other sites More sharing options...
flying dog Posted July 18, 2010 Author Share Posted July 18, 2010 SSSSSSSSSSSSSSHHHHHHHHHHHHHHHHHHHHHHH!!!!!!!!!!!!!!!!!!! Don't tell anyone! Link to comment Share on other sites More sharing options...
CraigRat Posted July 19, 2010 Share Posted July 19, 2010 don't/can't expect anyone to do it all for me, but here is a somewhat larger sample. I manipulate huge geodata sets all the time with the website I run, I can knock up something and spit it out in whatever format you want (wpt/gpx/kml)... wouldn't take long. Link to comment Share on other sites More sharing options...
CraigRat Posted July 22, 2010 Share Posted July 22, 2010 flyingdog, you have a shiny new GPX file in your email with all the points in it! Enjoy! Link to comment Share on other sites More sharing options...
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