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Wikiwide is offline Wikiwide
2014-12-10 , 23:16
Posts: 2,006 | Thanked: 3,351 times | Joined on Jun 2010 @ N900: Battery low. N950: torx 4 re-used once and fine; SIM port torn apart
#31
Originally Posted by sulu View Post
Yes and no.
GPS (and other GNSS systems) in principle work in space. LEOs (low earth orbit satellites) even use it for their own positioning.
The antennas of the GNSS satellites however are always pointed towards earth. So you still get signals even above the satellite orbit's, but only from the satellites on the other side of earth that are not blocked by earth itself. No idea how useful that is though.
I'm not sure if it will still work close to or on the moon but I'd think so (certainly not on its backside) but due to the distance you'd have to accept reduced accuracy.
You'll need professional receivers for this though, not consumer hardware like you'll find in smartphones or navis.

Earth-based GNSS won't work on or close to Mars, regardless of its relative position to earth.
I've read about similar approaches by using different Mars-orbiting satellites for rovers. But the accuracy won't be near anything you'd expect from GNSS as these satellites aren't made for it and there are by far not enough satellites up there for a complete system.
What's exactly the difference between "phone" GPS receiver and "professional" one? Besides more sensitive antenna, maybe - it would make a lot of sense to use directional antenna when on Moon and Mars?

Hoping that when they do start Mars-oribiting satellites for navigation, they will be compatible with GPS-Glonass.
Originally Posted by sulu View Post
"Hot" as in high temperature? No. It rarely exceeds 273K.
Ok. Its red surface probably misled me :-)

Wikipedia: Martian surface temperatures vary from lows of about −143 °C (at the winter polar caps) to highs of up to 35 °C (in equatorial summer).

Note to self: solar panels are not exactly helpful here. Low sunlight, dust storms...

Best wishes.
 

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mscion is offline mscion
2014-12-11 , 00:13
Posts: 1,873 | Thanked: 4,529 times | Joined on Mar 2010 @ North Potomac MD
#32
Originally Posted by sulu View Post
.
.
.
Capacitive screens tend(ed?) to have a lower "input resolution" than resistive screens.
Theoretically with the stylus I can control my N900 at pixel accuracy. Practically I get something between 3 and 5 pixels due to my shaky hand and not enough diligence during calibration.
I would recommend those with shaky hands consider using the pinch and zoom feature commonly found on phones with capacitive screens! With 1080x1920 pixels on my note 3, no need for stylus here! lol
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Wikiwide is offline Wikiwide
2014-12-11 , 02:09
Posts: 2,006 | Thanked: 3,351 times | Joined on Jun 2010 @ N900: Battery low. N950: torx 4 re-used once and fine; SIM port torn apart
#33
Originally Posted by mscion View Post
I would recommend those with shaky hands consider using the pinch and zoom feature commonly found on phones with capacitive screens! With 1080x1920 pixels on my note 3, no need for stylus here! lol
Two-fingers pinch and zoom work on resistive, too. As well as one-finger slide. As long as you have good touch-screen controlling chip ;-)

Best wishes.
 

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sulu is offline sulu
2014-12-11 , 06:47
Posts: 915 | Thanked: 3,209 times | Joined on Jan 2011 @ Germany
#34
Originally Posted by Wikiwide View Post
What's exactly the difference between "phone" GPS receiver and "professional" one? Besides more sensitive antenna, maybe
The main differences are:
1. Code only vs. code+phase measurements. Measuring the phase of a GPS signal highly increases the accuracy. There are some inaccuracies in measuring the satellite orbits which in turn lead to imprecise receiver position measurements. Then there are (at least on earth) atmospheric efffects and each receiver usually behaves a little different (unstable clocks, multipath effects etc.).
2. single vs. multiple (usually double) frequency receiver. Consumer receivers only measure signals on one frequency while professional receivers measure multiple frequencies. As some of the side effects depend on the signal frequency you can eliminate them by comparing the two signals.

As a result you can get an accuracy that is roughly 100 to 500 times more precise than what consumers experience. We're talking about single centimeters here, for some applications even several millimeters.

Originally Posted by Wikiwide View Post
- it would make a lot of sense to use directional antenna when on Moon and Mars?
Very much.
Another problem is that you have a very small parallax between satellites compared to earth-based measurements.

Originally Posted by Wikiwide View Post
Hoping that when they do start Mars-oribiting satellites for navigation, they will be compatible with GPS-Glonass.
No way. There are totally different signal types used. Usually lasers and radio frequencies.

Originally Posted by Wikiwide View Post
Ok. Its red surface probably misled me :-)
It's rust.

Originally Posted by Wikiwide View Post
Note to self: solar panels are not exactly helpful here. Low sunlight, dust storms...
They are. Every mars rover is equiped with them. But they are only half as efficient as on earth.
 

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Copernicus is offline Copernicus
2014-12-11 , 07:11
Posts: 1,986 | Thanked: 7,698 times | Joined on Dec 2010 @ Dayton, Ohio
#35
Originally Posted by sulu View Post
Every mars rover is equiped with them.
Well, most of the mars rovers are equipped with them; but the recent Curiosity rover uses RTGs instead.
 

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theonelaw is offline theonelaw
2014-12-11 , 07:27
Posts: 671 | Thanked: 1,630 times | Joined on Aug 2010
#36
Originally Posted by pichlo View Post
Nearly missed this...
RS232? Multiple USB? 7" 1280x800 resistive screen? I don't normally care for tablets but this is seriously interesting. Care to share the name/link? Or are you just kidding?
It is a mixed bag,
but it is the very best n900 replacement I ever saw
actually on the market -as-we-speak-.
Ruggon PM-311 RuggPad
x
That said, we (my company) can use them by the bucket loads
if they work as well as advertised, in a jungle environment.
We need them for their Intel architecture and the ability
to fly a linux distro. (Bay Trail Fails)
Our test sample should be in the field in few days.
x
If anyone here is interested let me know,
and I will simply add a device to our order and resell it out,
I will be consolidating an order (assuming it works)
as I imagine they are not set up to sell individual units.
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One for development testing Chopping Onions
One for saltwater immersion power testing resurrected ! parts scavenging

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Printing your Email with the N900
Last edited by theonelaw; 2014-12-11 at 07:44. Reason: offer
 

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tunap is offline tunap
2014-12-17 , 19:17
Posts: 6 | Thanked: 14 times | Joined on Dec 2011 @ PHX
#37
Originally Posted by Wikiwide View Post
Space-preparedness is an interesting topic. A challenging one :-)
The intricacies make for an entertaining read, though...
https://en.wikipedia.org/wiki/Packing_for_Mars


Back OT: I tried ditching my n900 for an N4 running SF OS EA4 in September but it hasn't work out. The latest beta seems to have fixed some issues & created others, so I bought another used N900 for spare/parts/inventory. Sigh...


Edit: PS: OT Again:
the very best n900 replacement I ever saw
actually on the market -as-we-speak-.
Ruggon PM-311 RuggPad
I cannot find a price on-site or through search. I imagine it's high. Anyone recommend/know of any other modern devices that sport a native RS-232 port?
Last edited by tunap; 2014-12-17 at 19:40.
 

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norayr is offline norayr
2019-08-26 , 15:57
Posts: 149 | Thanked: 217 times | Joined on Jul 2010 @ Yerevan
#38
the only things that changed so far are

>has Mappero, I did not find comparable program for Sailfish.

we have maep and pure maps. that's a relief.

>external bluetooth keyboard cannot be used with non qwerty layouts. I use dvorak or programmer's dvorak for Latin, and I also use Armenian typewriter layout. It's not possible with Sailfish yet.

i did this https://github.com/norayr/sailfish_h...yboard_layouts
but it only works for me on jolla device. which died.

and sony xperia xa2 doesn't recognize my bluetooth keyboards.
 

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Markkyboy is offline Markkyboy
2019-08-27 , 09:43
Posts: 433 | Thanked: 727 times | Joined on Oct 2012 @ Costa Blanca, Espaņa
#39
What is it with people and their constant comparison with other (dead) mobile OS's.

Nokia was a huge company, employing thousands of staff (an estimated 103,000 staff)

Jolla is a small company, employing about 50+ staff.

What more needs to be said?, why the thread?, it is so pointless.
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endsormeans is offline endsormeans
2019-08-29 , 03:01
Posts: 3,141 | Thanked: 8,164 times | Joined on Feb 2013 @ From my Gabriola Island hermitage, near the Edge of the World
#40
the thread was created like so many others ...
to introduce to those who are considering different devices and were interested in what pros and cons each has...
and to mention what functions or abilities keeps that person hooked and happy on that particular device .

Nokia is long gone from the maemo equation ...yes...dead ...no.
And they were a behemoth on the globe and could afford to invest in an experiment like the maemo line.
They lasted far far longer than Jolla ever will and accomplished far far more.
In fact ...Jolla wouldn't exist were it not for Nokia.

But all of that is neither here nor there...
Don't fret about it Mr. Crankypants
Soon enough Jolla will join the land of the dead
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