Fishing Trivia

[bigfish1965]

Here's a question that ties fishing into quantum physics!

What time of day is your GPS most accurate and why??

[Cookslav]

Alright I'll sport a guess but I'm gonna say at night...probobly Late at night when Solar flares, and other solar interference is limited being at that time of day we're faced away from the sun?

 

I'm probobly way off but its a guess to start the ball

[Bly]

Thanks Rick.....I now know way more about GPS time than I did and my head hurts LOL

 

Example..

GPS time is given by its Composite Clock. The CC or "paper" clock consists of all Monitor Station and satellite operational frequency standards. The system was previously referenced to one of the Monitor Station's operational frequency standards and switched from one station to another as needed. The GPS epoch is 0000 UT on January 6, 1980. GPS time is not adjusted and therefore is offset from UTC by an integer number of seconds, due to the insertion of leap seconds. The number remains constant until the next leap second occurs. This offset is also given in the navigation (NAV) message and your receiver should apply the correction automatically. As of January 1, 2006, GPS time is ahead of UTC by fourteen (14) seconds.

 

After reading this and more, my question to you is....which time are you using for accurate..local..UTC or TIA?

[BillM]

Hey Bly, I just read that also on the US mil site, lol....

 

http://tycho.usno.navy.mil/gpstt.html

 

I'm still confused btw

[BITEME]

Well best guess for me would be when a number of visable satelites are closest to earth in their orbits signals would take less time to reach reciever i havent got time to reall look at this as for time of day i would need more time to poke around the US navy website

Accuracy depends on satellite geometry, which varies with time

 

The system time reference is managed by the U.S. Naval Observatory in Washington, DC. GPS time is measured from Saturday/Sunday midnight at the beginning of the week. The GPS time scale is a composite “paper clock” that is synchronized to keep step with Coordinated Universal Time (UTC) and International Atomic Time (TAI). However, UTC differs from TAI by an integral number of leap seconds to maintain correspondence with the rotation of the earth, whereas GPS time does not include leap seconds. The origin of GPS time is midnight on January 5/6, 1980 (UTC). At present, TAI is ahead of UTC by 32 seconds, TAI is ahead of GPS by 19 seconds, and GPS is ahead of UTC by 13 seconds. Only 1,024 weeks were allotted from the origin before the system time is reset to zero because 10 bits are allocated for the calendar function (1,024 is the tenth power of 2). Thus the first GPS rollover occurred at midnight on August 21, 1999. The next GPS rollover will take place May 25, 2019.

 

For surveying purposes, the most accurate positional data are desired. Because the GPS satellites orbit the earth twice each day, their position relative to a point on the ground is continually changing. In addition, GPS satellites are taken 'off-line' occasionally for maintenance or a problem (See NANUs at USCG GPS web site). Therefore the quality of a GPS-derived position can vary. This condition is called Dilution of Precision or DOP. There's a class of GPS analysis software that can help the user determine the best time for precise data collection

[bigfish1965]

There's actually a quantum time/space factor I was referring to.

It goes something like this..

Gravity effects time. It slows it down. Since the satellites are further from the effects of gravity, their clocks run slightly faster than clocks on earth. So each day at 5:00 pm, the military recalibrates the time between earth and satellite clocks.

There's some great shows on you tube from a British Science TV Show starring a british scientist about this phenomenon...great until your head explodes...

[ccmtcanada]

I never look at my GPS for the time. I didn't even know it had the time.

 

I have this thing on my wrist called a watch that tells me the time. Well....to be honest, I have to read it...it tells me nothing. My mom however has a talking watch...that one tells her the time.

 

What was the question again?

[Ramble]

LOL

 

The question i believe was gravity...Friend or Foe?

[desship]

What causes GPS to lose signal.It happens on fishfinder everyday around 11.10am but signal is re-acquired 15 or twenty minutes later.On my handheld you can see the strength from each sattelite but on fishfinder you can't see what the sattelite strength is.I thought maybe it was my location Port Darlington but same thing happened at lake Tamagami

[Roy]

What causes GPS to lose signal.It happens on fishfinder everyday around 11.10am but signal is re-acquired 15 or twenty minutes later.

 

Which unit do you have?