I hate technology (namly GPS)

dgpw · 06 February 2004, 08:27

Hi all don't know if anyone can explain this. Was running a night exercise Sunday night around Plymouth (yes it was windy). 4 GPS's of different varieties. Plotted some waypoints on the chart. (Datum wgs84) entered into 2 gps's one garman 12 and one Magellan 115 and went out on the water. They were completely up the spout one was claiming that the Yelm was 2 miles up the Tamar!! tried going to positions that I know are correct and have used hundreds of times and these were out by miles two. We had good strong satellite fixes and the units were saying that their was a good accuracy. I swiched one to datum wgs72 as it is very nearly the same as wgs84 (the difference is altitude) and this started to work. Then the all worked going south and not north. and then they all started working propoly. This is very strange as we checked the health of the system and every thing was ok.

anyone got any ideas?

Rupert Bear · 06 February 2004, 09:19

I have noticed that I have been getting accuracy alarms for the last couple of weeks, are we going to war with somebody new this month?

dgpw · 06 February 2004, 19:03

um just what I was thinking but I have been assured that they uses a different coding for the servises. Hume i don't beleve them

DJL · 06 February 2004, 19:25

If anything GPS gets more accurate during war - during the first Golf War they turned off selective availably because the armed forces were using civilian sets.

Selective availability was completely stupid anyway – like it matters if a nuclear bomb is a few 100m of target

Red Fox · 06 February 2004, 19:52

Maybe not but a GPS guided ball could make a difference to your handicap!

karlT · 07 February 2004, 18:39

Hi Dave,

Long time no hear? Fancy a delivery in March Jersey - Greece?

Cant answer your GPS question other than to ensure they are all set to WGS 84 and details have been put in correctly. You sure they named and numbered them correctly I know some Uni students in Plymouth can be a bit slow at times ???

In an urban environment you get multibeam reflections of the buildings which can screw the readings but unlikley to be 2 miles out?

Cheers

Karl