ScoutMaster GPS
18 messages in this thread
I received some info on the new Trimble ScoutMaster GPS today. The following
are some of the new features. The physical characteristics are the same as the
Scout.
* New price – $995
* New map coordinate system – "Topo GPS" Will tell you by name and state which
one of the 53000+ USGS 7.5' topos you are on and which 2.5' quadrant of that
topo you are in. It automatically sets the SE corner of that quadrant for
over & up calculations.
* Diff GPS capable
* S/A filter which keeps the ScoutMaster from wandering around when it is
standing still (I guess we won't need the supplied lanyard any more).
* Acu-Lock – The brochure says "10 meter static solution without differential
correction" – Trimble tech support had no info on this feature as it will not
be shipping until Oct.
* RS-232 interface with a software utility to swap data between the
ScoutMaster's library and a spreadsheet.
For $1395, you get all of the above plus the external antenna/battery
eliminator package and the Scout It Out software package. SIO provides the
capability to graphically view locations on a computer (from the ScoutMaster's
library or created with a spreadsheet) and to plot location data to scale for
printing overlays on any topo map. SIO will also allow the use of a portable
computer for real time data collection. All software is for IBM compatibles
with Mac versions to be released "soon".
There are a couple other features available. One is an Apple Newton PDA
interface and the other has to do with SMTE time codes (whatever that is) for
the A/V industry.
— Bill
That's SMPTE, the Society of Motion Picture and Television Engineers. It's a
way to measure (time-stamp) film and video.
John —
Why would they need a GPS to time stamp film and video? I was thinking maybe
they could use it to keep their cameras and stuff running at excatly at the
right speed.
— Bill
Bill-
Also for a few hundred $ a year you can hook into a paging system that uses
FM subcarriers and sends a reference signal for real time differential
measurements. It is not like having a transmitter across the street but you
can get 3-10m accuracy with no trouble. Only for US, and even then limited,
right now but you know how the pager areas are growing.
We thought this would knock the price of the Scout down a couple of hundred
but it is holding on for now. With the down pressure from Magellan and others
I would expect either a decrease when the ScoutMaster has been out a while or
maybe a phasing out-who knows.
However, the SM looks like it will be the first of a new generation at
affordable prices (it is comprable to others costing $3000)
Steve
Hi Steve —
I don't know why Trimble doesn't drop their prices so dealers could sell them
for say, $500. It seems like they could sell a zillion of them. I have
participated in a lot of discussions here on CIS and most everyone thinks the
Scout is way cool but can't justify paying $700 or so when they can get a
Garmin for about $350. Those are sales Trimble will never get at their current
prices. I guess they will just have to depend on REAL gadget geeks like me. Oh
gawd – I have to ask – How much would the SM set me back? I don't have to worry
about it right now though because they don't have the software for Macs yet.
I really don't need much more accuracy than I am presently getting but I am
curious about this FM subcarrier diff stuff. If I was poking around near Nevada
City and the nearest FM transmitter was in Sacramento, I would be maybe 50
miles away and about 4000' higher than the transmitter. Would the diff
correction be valid under those conditions? Or, how about if you were trying to
find your store in Pasadena and there were transmitters in Santa Monica and
Anahiem – would this pager gizmo select the nearest diff transmitter or does it
matter?
Thanx —
— Bill
Bill-
More on the differential stuff. They are also on in Europe and Australia and
have about 100 stations here with plans for 150 more within a year. You get a
pager ($300) and then there are three levels of service. I may have the
numbers a bit wrong but it is something like 5-10m accuracy-$200/yr, 2-5m
accuracy- $400/yr, and 1m accuracy $600/yr. I suspect it has something to do
with multiple channels and error correction in the pager. So, such accuracy
would be great for LA, Bay area,or any major urban area but I don't think it
would work well anywhere where FM reception were poor-a good measure would be
whether your pager worked in a particular area.
Use of Newton or other things would be just a data logger and interface. You
can get the Scoutmaster Field Kit with all this stuff,external antenna, etc.
With new DeLorme software, a Newton, and a CD ROM you could have James
Bond-quality real time, precise location on street maps throughout the US.
And now the costs SM is $995, with Field Kit 1395; you will see some street
price decrease but probably not until all the order are caught up in the next
few weeks. If you see a cheap price soon, make sure they really have them in
stock to sell-some will some won't. On the other hand this is not much higher
than Scout at $795 list.
I got a demo of the Rockpecker ID program. I am not yet overwhelmed but it
is good for the money. More on that later.
Steve
Steve —
Does the pager work as a normal pager too? Wouldn't a better measure of how the
thing would work be how well you could get the station that is broadcasting the
sub-carrier? Or, do all pagers use a sub-carrier? I thought pagers use thier
own transmitters.
Do you know anything about the Acu-Lock feature on the ScoutMaster?
Thanx
— Bill
Bill-I will bring home spec sheet for more info-I suspect it is an averaging
program but who knows. We still don't have them yet.
Steve
High Bill: I've been away for a while, and probably missed a lot on this forum.
To answer your question about differential corrections: yes, the corrections
would still be valid at the accuracies you're talking about. The height
difference would probably introduce more errors than the 50 km horizontal
difference. Dynamic offshore surveys achieve 5 m or better with ranges to
differential stations of well over 500 km. Some suppliers claim no degradation
out to 1000km. What you do need to be sure of is that the diff stations you're
using are properly installed and monitored. I've seen instances of multipath
effects of up to 15-20 metres corrupting the diff corrections broadcast from
the reference stations. If you're moving, you've also got to watch out for the
update rate of the corrections and the time lag from signal reception at the
reference antenna until the corrections update your position computation.
Within limits, selection of the nearest correction transmitter doesn't matter.
Some systems autoselect the nearest. Some allow manual selection, and some
(the more expensive) take a weighted mean of all reference stations " in view".
Trimble has been working on a Wide Area DGPS (WADGPS) system which would cover
a major continental mass with about 4-5 reference stations.
It might interest you to know that I've just completed a land survey using both
conventional techniques and a Trimble SSE Total Station and Rover pack. The
conventional survey took 4 days and closed out to 5 cm ( 2 ins) at the 2 sigma
level. The GPS work was done using "stop /go techniques. It took 1 day. The
biggest bust with the conventional control was 38 mm ( yes, millimetres) in
Northings. This was out of 200 comparison points, so it wasn't a fluke.
For your info, I've just applied to CIS, on behalf of the Hydrographic Society,
to run a "Survey and Hydrography" Forum. If the proposal is approved, we intend
to devote an entire section to GPS, covering everything from high precision
geodesy to casual leisure use. I'll keep you posted as to whether it's going
ahead.
Rob
Rob —
Thank you for the info on the diff corrections vs distance from the
transmitter. Again you have answered a question I have been curious about. I
hope CIS blesses your new forum proposal. If it is like the GPS internet
newsgroup, I probably won't understand some of it but I know I will pick up
some useful info.
— Bill
It did seem like a strange option to me, but I can think of one example. A
friend of mine (in the video biz) had a big contract with a railroad company.
They have video footage of every inch of their tracks. Yes, that's a big video
library. They have a special "geometry car" that drives the tracks. It has four
video cameras pointing outward. Yes, that quadruples the size of that video
library. 🙂 If they had a GPS on-board, and maybe they already do, then they
could sync the video and GPS read-outs. Maybe the GPS is just functioning as a
clock in that mode…
John —
You are probably right about the GPS being used as a clock. I was thinking that
to make say a music video, several recordings are made at different times and
places and they all have to be in sync when they are mixed together. Timing
accuracy may be even more important with digital recording but all this is
esoteric stuff I don't know much about.
— Bill
Bill… yes, they do have a GPS on board, for both time and position!
Rob
Hi, Bill–
Thanks, this is interesting info.
I don't suppose you know whether the Newton PDA, given the interface and
software as needed, would also be able to plot the position on a map?
–Doug
Doug —
All the brochure says is the Newton is used as the data entry and output
device. Maybe Steve Ryland can elaborate.
— Bill
Thanks for the info Bill,
but shouldn't these things be like computers–new models have more
feataures/capabilities and _lower prices_?
Lanny
Lanny —
I think Trimble is trying to buck the trend and go the way of the auto industry
– more feataures and capabilities and a higher price. I wouldn't think the
Scout has any more hardware than the others but I can see a higher development
cost for the software. If they dropped the price, they would be able to spread
the development cost over more units and ultimately make more money. I would be
happy if there was some upgrade path for the new unit.
— Bill
Trimble has a huge product range. They've been most active in the surveying
markets, which they've got practically sewn up. Most of their "economy " model
units are built on the back of work that was originally done for the survey
market. They have a good level of support, very robust engineering, and a large
development effort. I'm not saying that suppliers like Garmin are bad, but it's
horses for courses. Garmin can be likened to the "box shifter" end of the PC
market, whilst Trimble tries to offer a "value added" product. Without
Trimble's ( and others) pioneering engineering, Garmin and the like would never
have got off the ground. Why do people always think that software should cost
nothing <g>?
If I have a problem with some esoteric data mismatch, I go to Neil Ackroyd at
Trimble. I doubt that there's anyone at Garmin who would understand my
question. I'll continue to support Trimble, Ashtech and Sercel until GPS
becomes a "white goods" product, and all the peculiarities of its use have been
solved!
Rob