Free software from Trimble to determine best time of day for most accurate fixes

[+Poindexter]

Here's the link:

 

http://www.trimble.com/planningsoftware.html

[Kerry.]

A bit of a killer at over 22mb for straight/simple mission planning software and does nothing more than all the rest.

 

I'd be going with either leica's Satellite Availability

 

http://www.leica-geosystems.com/gps/almanac/

 

or Ashtech's MP_win

 

http://www.thales-geosolutions.com/skyfix/gpsinfo.html

 

Cheers, Kerry.

 

I never get lost everybody keeps telling me where to go

[crr003]

quote:

---

Originally posted by Kerry:

.......

I'd be going with either leica's Satellite Availability

 

http://www.leica-geosystems.com/gps/almanac/

 

.......

Cheers, Kerry.

 

I never get lost everybody keeps telling me where to go

---

 

Just had a look at this - way too cool. When I figure out what it all means I'm sure it'll be useful! There's some really clever looking stuff out there - I sit and watch VisualGPS when there's nothing else to do (sad).

 

Nil Satis Nisi Optimum

[+apersson850]

I tried to apply the Leica software to my location. Seems to fit in pretty well with what the Vista thinks of it, too. Now one can probably by backward engineering figure out what mask angle the Vista uses. Need to know everything.

 

Anders

[crr003]

quote:

---

Originally posted by Anders:

I tried to apply the Leica software to my location. Seems to fit in pretty well with what the Vista thinks of it, too. Now one can probably by backward engineering figure out what mask angle the Vista uses. Need to know everything.

 

Anders

---

 

When I've used VisualGPS my Garmin 3+ will show me using sats till they fall off the map. Kerry once commented that recreational receivers have the mask angle "opened up". Interested to see what the Vista does.

 

Nil Satis Nisi Optimum

[+creagerstonefamily]

What's the most important/relevant chart in the Leica program: the VISibility or the SUMmary?

 

Just to make sure I'm doing this right. If I plan to go caching from 10am to 4 pm, I set the top slider to 10, the bottom to 16, and view the visible satellites on the chart, right?

[Kerry.]

quote:

---

Originally posted by CreagerStone Family:

What's the most important/relevant chart in the Leica program: the VISibility or the SUMmary?

---

 

To me initially it's the DOP (PDOP/GDOP overlayed over the number of Sats) but depending on the requirements/situation some of the other charts can also be useful.

 

By studing the DOP chart one might notice that there's no "absolute" correlation between the number of Sats and the PDOP/GHDOP. "Generally" the more Sats the lower the PDOP/GDOP but have a close look as the best times are basically when the PDOP/GDOP is the lowest, not necessarily when there's the most Sats.

 

System accuracy specifications are based on a PDOP of 6 or less so above 6 (generally rare these days) one should be a little vary but to me the GDOP is more relevent.

 

The SKY plot can be useful with respect obstructions especially when windowed. By graphically adding the obstructions then that generally has a tendency to change the overall plan (depending) and all the other plots.

 

Really there's a lot of flexibility in most mission planning software but just make sure the Almanac is updated regularily.

 

Also another interesting thing is to selectively toggle off (1 or several at a time) the Sats (vertical bar down the right hand side) and note the affect on the availability/plots.

 

Cheers, Kerry.

 

I never get lost everybody keeps telling me where to go

[+apersson850]

I know that the Vista has different mask angles, depending upon if you use normal or battery save mode.

That's to avoid spending energy on CPU cycles to hunt satellites that are difficult to receive anyway, when you want to save your power.

 

I'll have to do some tests, but now I have to send my Vista to Garmin again, so it may take some time before anything happens.

 

Anders

[dave and jaime]

not a techie type question but maybe one of you gurus can help anyway, i downloaded the leica version and i have trouble with the help option, an error message says that there is a *.dll file missing from my c:..system directory and an updated help file exists, if i hit ok 4x's the help feature seem to load as it should!

 

besides this quirk, i love what the potential for the application is!

[Team Sidewinder]

Anders, What kind of problems are you having with your vista ? Same one you sent it in for last time ?

 

Just wondering if I bought from the wrong gps company. Just curious

sidewinder

 

LOST AND FOUND DEPT.

[Forester II]

Thanks Kerry,

 

I miss the planning software on the work computer.

[+apersson850]

This is my second Vista, since they replaced it three months ago. My first unit had the flickering lines across the display problem now and then.

The second one now has one pixel row horizontally over the screen gone white all the time.

I think you bought from the right company, since they offered to replace this one too under warranty, in spite of the fact that the original purchase was in September 2001.

So the company is good, but some of their products aren't 100% good.

There certainly was no abuse involved in this second problem, since the unit was lying in a hotel room when the line suddenly was there when I turned it on. Pressing hard with a finger near the power button helps sometimes, so it's most certainly a hardware problem.

 

Anders

[+apersson850]

My first tests (haven't shipped my Vista yet) shows that the mask angle when using normal mode is at least no more than 5º. It may be very close to 0º.

When using battery save mode, it seems to be a little less than 10º.

It takes a while to get suitable satellite constellations to try with. You have to have some sats low on the horizon to find out this "reverse engineering" way.

 

Kerry, the satellite prediction software wants you to tell it which altitude you are on. Although I can understand that that makes a difference regarding how many satellites you can see from the earth, I'm not sure about what to set it to right now. My current elevation is about 140 meters above MSL.

Does the GPS (in this case a typical consumer thing, the eTrex Vista) use it's altitude in the calculation of which satellites to see? Or does it apply some assumption, like sea level? Does it really matter that much, being in a farily flat part of the world, without any bigger hills around?

I'm just trying to figure out if the altitude I set in the satellite software makes any real difference to the views I see on the screen, compared to the satellite view the Vista computes on its own.

 

Anders

 

[This message was edited by Anders on February 07, 2003 at 01:00 AM.]

[Team Sidewinder]

quote:

---

Originally posted by Anders:

This is my second Vista, since they replaced it three months ago. My first unit had the flickering lines across the display problem now and then.

The second one now has one pixel row horizontally over the screen gone white all the time.

I think you bought from the right company, since they offered to replace this one too under warranty, in spite of the fact that the original purchase was in September 2001.

So the company is good, but some of their products aren't 100% good.

There certainly was no abuse involved in this

second problem, since the unit was lying in a hotel room when the line suddenly was there when I turned it on. Pressing hard with a finger near the power button helps sometimes, so it's most certainly a hardware problem.

 

Anders

---

 

Hope the trip to Garmin and back to you is a short one. Thanks for sharing your problem. I had a 12XL before this one and had it about 4 years when the internal memory wouldn't hold when ever I changed batteries. Sent it into Garmin and they replaced it with a factory remanufactured without any questions.

Thanks again

sidewinde

 

LOST AND FOUND DEPT.

[Kerry.]

quote:

---

Originally posted by Anders:

.... Kerry, the satellite prediction software wants you to tell it which altitude you are on. Although I can understand that that makes a difference regarding how many satellites you can see from the earth, I'm not sure about what to set it to right now. My current elevation is about 140 meters above MSL.

Does the GPS (in this case a typical consumer thing, the eTrex Vista) use it's altitude in the calculation of which satellites to see? Or does it apply some assumption, like sea level? Does it really matter that much, being in a farily flat part of the world, without any bigger hills around?

I'm just trying to figure out if the altitude I set in the satellite software makes any real difference to the views I see on the screen, compared to the satellite view the Vista computes on its own.

 

Anders

---

 

Theoretically it probably does but practically one would probably not see any real difference considering that most planning software has max limitations in input and that input is fractional when compared to the earth radius and satellite orbits.

 

Since this type of software isn't really required to be "precise", (in that say computed outputs are in whole integer degrees) the output is appropraite for the planning purpose. If you experiment with different heights (like 0 and 10,000m) and study the Azimuth and Elevation table (closely) one might see some "minor" variations, where an elevation is different (rounded) by a single degree (here and there).

 

Have no idea how the Etrex thinks about things but it probably doesn't matter all that much.

 

Cheers, Kerry.

 

I never get lost everybody keeps telling me where to go