Gps At Night

[+Deepdiggingmole]

This may well have been discussed before, but rather than spend an hour trawling through old threads - I thought I would do a new one (it would be easier to find later too

 

Ok - simple question - do GPS work at night as well as they would during the day ?

 

This is probably a very obvious thing to answer - but I had an experience the other day where in trying to be FTF I went out to a location around 10pm and my Garmin seemed to be working fine but getting a sensible reading near the cache was nigh on impossible - I was in woods which I know will have affected the reading. I am interested to know if the reading would have been any better during the day.

 

Tim - ddm

[+DocW]

They don't switch off the Sats at night!

And next time try to switch on the display's backlighting, this helps a lot.

 

The only reasonable thing I could think of would be reduced signal by wet leaves at night due to dew.

[+EraSeek]

All other factors being equal, your GPS will work better at night because there is much less ionospheric disturbance, thus less slowing of the signal and higher position accuracy.

[HugoOne]

The 28+ GPS satellites twirl around the globe day and night, the system is setup so that you should get at least 4 in view anytime anywhere (I'm not sure about the polar regions). Their radio signal is invisible and not affected by light or dark environments.

Some things like solar wind (1) do affect the signal but it's more likely that your problems were due to down to earth interferance, wet leaves, your body, GPS orientation ...

 

(1) http://solar.sec.noaa.gov/rt_plots/kp_3d.html

Edited November 4, 2005 by HugoOne

[+Renegade Knight]

You can have a different error at night than by day. A friend and I went to his cache and while I was looking my coordinates had me 20' out over the rim of a canyon. So did his, and he was puzzled as heck. After I found it he said that he normally checked up on it at lunch and his coords usually had him back from the edge.

 

I'm not sure there was anything different than the satalite geometry at that time.

[+Deepdiggingmole]

"Stupidity has a certain charm - ignorance does not. (FZ)"

 

I hope this wasn't being directed at me - Yes, I do know how my backlight works !! and strange thing - I had a torch with me too

The point was - never having been out on a cache hunt at night I wasn't sure if the GPS reacted differently. logic told me not, and having been back to the area during the day when very clear and sunny I found that at this particular location the GPS signal was much affected by the tree cover - and the signal was reacting in much the same way as when i had gone at night

 

Tim - ddm

[earthshaker]

This is a signature block if you look at most of the posts you will see a wide variety of them, relax.

 

"Stupidity has a certain charm - ignorance does not. (FZ)"

 

 

Anyway I have never used my GPSR at night, but knowing about radio waves in theory the GPSr will work better, I agree with the post that stated due to dew, the signal may have been blocked. Vegetation of any kind can create problems with radio waves at higher frequencies in general, I am not sure where you are from, but try this if possible take your cellphone out to a tall corn field in the late season, you will find that unless a tower is nearby you will not have a decent signal. But on the other hand if you and a buddy go to the same cornfield at the same time of year as the cellphone example above, with say cb radio with one of you on each side of the cornfield you will be able to hear each other with little degradation of signal, of course that depends on the quality of the signal overall, since I did use cb radio as an example.

Now for the technical overload part.

The GRSr recieves at a frequency between 1200 and 1500 MHz, Cellphone 800-900MHz, FRS radio 460MHz, CB radio 27MHz.

as a general rule lower frequencies penetrate vegation better.

 

BTW did you get the FTF?

[+Tervas]

Yes they work at night, I have even signed some logbooks using the backlight of my eTrex ('twas better than my cell phone light) , forgot to take flashlight/torch with me

[BilgeRat]

I work as an engineer on a towboat that works the Lower Mississippi River. When I am at work, my 60c is mounted in the window of the engine room office with an amplified antenna mounted on a second deck handrail. We leave it on 24/7, and it works just fine in the dark! We have point to point routes for the areas that we run in; this way we have eta's available, etc. Happiness is never having to ask the pilothouse where we are

Tom

 

P.S. Think about this, too. GPS is is used worldwide for ocean navigation, and ships don't stop at night---

[+northernpenguin]

You can have a different error at night than by day. A friend and I went to his cache and while I was looking my coordinates had me 20' out over the rim of a canyon. So did his, and he was puzzled as heck. After I found it he said that he normally checked up on it at lunch and his coords usually had him back from the edge.

 

I'm not sure there was anything different than the satalite geometry at that time.

Better find my caches at night then. Nevermind finding caches (70% of my finds are night caches), I go out and *HIDE* caches at night. It's cool to sit there on a beach and try to spot the gps satellites go by, from using the constellation screen on the GPS.