SSF to Rinex conversions.
dhur...@imap1.asu.edu
format. I have access to the files that I need, but neither of the base
stations that I can get the files from will convert them to Rinex for me.
Trimble has a utility to convert its ssf files to rinex, but it is an
expensive piece of software because Trimble has told me it is only
available with purchase of PFinder. My problem is that I only need to
have temporary access to another base station; I will have access to a
Magellan station within the next few months and will no longer need
access to an outside station. My questions (needs) are as follows:
1. Is there a shareware utility for converting SSF to Rinex? If so, where
can I get it?
2. Barring #1, does Trimble publish its file formats? I have access to
the Rinex specifications, and I would write a program to convert files
myself if I had the information on the Trimble files.
3. Are there any other ideas about how to convert this data or where I
could get alternate data. I am in the Phoenix area, so I need a station
near enough to get within about 5 m accuracy.
If you send any replies to this query to my address, I will summarize
responses for the list and for any interested party.
Thanks in advance,
Dennis Hurlbut
dennis....@asu.edu
Mark MacLennan
>I am interested in converting some SSF base station files to Rinex
>format. I have access to the files that I need, but neither of the base
>stations that I can get the files from will convert them to Rinex for me.
>Trimble has a utility to convert its ssf files to rinex, but it is an
>expensive piece of software because Trimble has told me it is only
>available with purchase of PFinder. My problem is that I only need to
>have temporary access to another base station; I will have access to a
>Magellan station within the next few months and will no longer need
>access to an outside station. My questions (needs) are as follows:
>1. Is there a shareware utility for converting SSF to Rinex? If so, where
>can I get it?
Nope. The SSF format is proprietary (not in the public domain) and
therefore no one but Trimble could write such software legally.
>2. Barring #1, does Trimble publish its file formats? I have access to
>the Rinex specifications, and I would write a program to convert files
>myself if I had the information on the Trimble files.
Nope. See above. Aren't proprietary data formats wonderful in this
regard!
>3. Are there any other ideas about how to convert this data or where I
>could get alternate data. I am in the Phoenix area, so I need a station
>near enough to get within about 5 m accuracy.
Maybe you could find someone in the Phoenix area with the Trimble PFINDER
software who could do the conversion for you. (Like the source of
your data in the first place ...) Alternatively, you might be able to
rent a Trimble GPS base station and get access to the software that way.
Check a magazine like GPS World for such rental sources.
(note: the PFINDER software requires a "security key" device be put on the
parallel port for it to run).
- MARK
--
------------------------------------------------------------------------
Mark J. MacLennan, Data Systems Coordinator
Center for Global & Regional Environmental Research (CGRER)
Eric Gakstatter
dhur...@imap1.asu.edu says...
>
>I am interested in converting some SSF base station files to Rinex
>format. I have access to the files that I need, but neither of the base
>stations that I can get the files from will convert them to Rinex for
me.
>Trimble has a utility to convert its ssf files to rinex, but it is an
>expensive piece of software because Trimble has told me it is only
>available with purchase of PFinder. My problem is that I only need to
>have temporary access to another base station; I will have access to a
>Magellan station within the next few months and will no longer need
>access to an outside station. My questions (needs) are as follows:
>
>1. Is there a shareware utility for converting SSF to Rinex? If so,
where
>can I get it?
>
>the Rinex specifications, and I would write a program to convert files
>myself if I had the information on the Trimble files.
>
>could get alternate data. I am in the Phoenix area, so I need a station
>near enough to get within about 5 m accuracy.
>
>responses for the list and for any interested party.
>
>Thanks in advance,
>
>Dennis Hurlbut
>dennis....@asu.edu
>
Try the NGS base stations. They store data in Rinex format. The FTP site
is proton.ngs.noaa.gov. They may not be as close, but if you sit on the
point for a minute or so, you should hit 5M (at least if you were using
an MC-GPS).
Good Luck,
Eric Gakstatter
eri...@peak.org
canam
format, meaning you have to buy PFINDER. Even their GEO-PC program that
comes with the GeoExplorer won't support SSF to RINEX conversion.
Too bad. It's one black mark against them from a marketing standpoint.
Steve Robertson
Agreed!
I have spoken to Trimble about this and they say that they will not be
releasing the SSF format anytime soon. They were of the same opinion a year
ago with their geodetic processing software, GPSurvey. They got a lot of
complaints and pressure from government clients. Now, they have full RINEX
in/out capbability. I think that the mapping products end will get with this
decade sooner or later, though. We should all encourage them as much as we
can. BTW, you can usually get hold of Trimble people via e-mail by using
their name with trimble.com (eg. charlie...@trimble.com). Chuck Gilbert
is probably the guy to talk to (he'll kill me for this...)
Trimble's RINEX support (at least for PFinder) also leaves much to be desired.
They require the D1 observable (i.e. Integrated Doppler count on L1) to be
present in the file. I think that they use this they use for carrier
smoothing of the code phase observable. This means that I cannot process
other manufacturer's base or rover data with MCORR/Pfinder (not that I can
think of a good reason to use MCORR when I could use a psuedorange correction
program), unless that manufacturer outputs the Doppler. Most other people use
C1 and L1 (C/A code on L1 and carrier phase on L1) in their GIS level
receivers.
Why would we want to use Trimble data in the RINEX format?
1) There are many Trimble base stations out there, operated by private
industry and government. Some people would like to use Garmins,
Ashtecs, etc. in the field and use these Trimble base stations rather
than set up their own.
2) I often want to use a more sophisticated processor than MCORR/Pfinder.
The Trimble Pathfinder Pro XL is a _very_ good single frequency code
phase receiver, but the software is not capable of getting the utmost
accuracy out of it. If I could use, for example, Pulsearch's Jupiter
which corrects psuedoranges and will allow for statistical testing for
noisy ranges, I could increase that accuracy two fold or more (and I
have the _scientific_ data and analysis to prove it!
3) The Geodetic Survey of Canada has written a brilliant program called
GPSPACE which uses precise clock and ephemeris data instead of a local
differential base station. This allows me to extend positioning to
places like the Arctic and Africa which have no infrastructure of base
stations, and where to deploy a base may have a prohibitive cost (a
Bell 206 goes for about $1000 per hour without fuel in the North!).
One problem with using RINEX files from _any_ manufacturer is that there is no
provision for attribute data in the RINEX standard. So, no matter if you are
using a Trimble, a CMT (Magnavox), or a "Blue Lightning Special", you are
going to have to deal with corresponding GPS positions and the features you
are surveying. To that end, I asked Trimble if they would just release the
format for attribute records in the SSF file, and got a bit more interest, but
still not that much. I am going to pursue this and I encourage others to do
so as well.
Note that this is not necessarily an attack on Trimble ;), since many of the
other manufacturers have similar policies. I am an independent GPS consultant
and trainer and have had some experience with most of the mapping and geodetic
GPS systems available. Trimble is not unique in this, they are just the
biggest one. If they get with the program, the rest will sureley follow!
Anyway, enough rambling! This just happens to be a sensitive issue with me as
well as much of the mapping GPS community up here. Let's have some feedback
from the rest of you. I have seen posts from Kelly Bobitt (Trimble) here and
would like them to jump in (if you dare...).
steve
==========================================================================
Steve Robertson ste...@mindlink.bc.ca
Tangent Survey Systems
302 - 1728 Second Avenue East tel 604.255.8754
Vancouver, B.C. CANADA V5N 1E2 fax 604.255.0599
==========================================================================
canam
I've also been raving about the Geomatics Canada GPSPACE program to
anyone who will listen. I've worked with data sets throughout Alberta and
more recently in Kazakhstan (using the ProXL) with amazing results.
Robert Duvall, the man at Geomatics Canada who manages the development of
GPSPACE told me that they have approached a number of manufacturers,
including Trimble, to take over development and marketing of the product.
No takers, so far. I guess they feel it will cut into their hardware sales.
Scott Partridge, P.Eng ph: (403) 276-5561
Manager, GPS Services fx: (403) 276-5566
Can-Am Surveys Ltd em: ca...@cadvision.com
Calgary, Alberta, Canada
T3E 1E3
John Willis
>Steve, you got that right regarding Trimble's view of the marketplace.
>
Does all this mean it is or is not illegal to simply read their
binary files and write a basic binary to text decode program
of exactly what's in there?
I've taken a look, and it's not as sophisticated as you might
think....there's quite a bit of redundant data. Over lapping
frames almost decode themselves.
But I'm debating whether it would be safer to use a less
hostile company's output.
How about if you did it and distributed the program, not the
file format for free? I have no knowledge of Trimble file
formats, but they make the files available and it's not exactly
encoded with a key. If they were the fields would shift
cyphers and they don't, least not that I can see.
ste...@mindlink.bc.ca
>
> Does all this mean it is or is not illegal to simply read their
> binary files and write a basic binary to text decode program
> of exactly what's in there?
>
> I've taken a look, and it's not as sophisticated as you might
> think....there's quite a bit of redundant data. Over lapping
> frames almost decode themselves.
>
Yes, you could probably do that. The SSF format is somewhat
repetitive, once you get past the file headers. The header
records for each epoch depend on what options you have set,
and you would have to consider that you could (and should)
store psuedorange measurements as well as positions. Odd
records do pop up, such as when the constellation being
observed changes - just to keep you on your toes.
But, of course, reverse engineering would violate patents
and be illegal - oh, well!
> But I'm debating whether it would be safer to use a less
> hostile company's output.
>
I think that we should be very careful here. In my dealings
with the Trimble people, they are _NOT_ a "hostile" company.
In fact most of the people there are helpful and responsive,
especially once you find the right person to ask about a
specific product. Trimble, like many other companies is just
trying to protect themselves in the marketplace, although
I think that they are misguided on this issue.
If you read my post on this topic from 07 June, I make the
point that most companies offer poor or grudging support for
the RINEX standard. Some are worse than Trimble, and there
are some companies with very good support for RINEX. So
although Trimble is the largest GPS company and they don't
fully support RINEX, to call them "hostile" is a bit much.
One company which could be called hostile and arrogant is
Trimble's neighbours in Sunnyvale (who, BTW, produce a very
good geodetic receiver). Another company who writes a
mapping data collection package tried to sue everybody a
couple of years back for using the terms "GPS" and "GIS" in
the same breath (yeah, and I've got a patent on the using
"shoe" and "lace" together! ;) ).
I think that there are very good reasons for all manufacturers
to provide full RINEX in-out support without asking for a
huge extra investment. If they adhere strictly to the
RINEX format (which is not nearly as inefficient and
changeable as the manufacturers claim!), and write some
intelligence into the processing software so that whatever
observables are present are accepted, then we could be
looking at a fully open system.
Steve Moore
>Does all this mean it is or is not illegal to simply read their
>binary files and write a basic binary to text decode program
>of exactly what's in there?
>I've taken a look, and it's not as sophisticated as you might
>think....there's quite a bit of redundant data. Over lapping
>frames almost decode themselves.
Their SSF format is the ONLY format Trimble will not release.
We have documentation on all their other formats (TSIP, TAIP,
TrimVec, TANS, DataCollector, etc.) and have included them
in our "pcextract" post-analysis product, along with over 30
other receiver formats.
My contact at Trimble said it was the most compact format ever
invented, and is extremely proprietary. I haven't seen it
but I suspect it wouldn't be worth the effort to try decoding
it. If you can get your data in any other format, we have the
software to allow you to post-process and analyze it.
Steve Moore
President
MAI
Barry L. Lankford
>> jo...@entc.tamu.edu (John Willis) writes:
>>
>> Does all this mean it is or is not illegal to simply read their
>> binary files and write a basic binary to text decode program
>> of exactly what's in there?
>>
>> I've taken a look, and it's not as sophisticated as you might
>> think....there's quite a bit of redundant data. Over lapping
>> frames almost decode themselves.
>>
>Yes, you could probably do that. The SSF format is somewhat
>repetitive, once you get past the file headers. The header
>records for each epoch depend on what options you have set,
>and you would have to consider that you could (and should)
>store psuedorange measurements as well as positions. Odd
>records do pop up, such as when the constellation being
>observed changes - just to keep you on your toes.
>But, of course, reverse engineering would violate patents
>and be illegal - oh, well!
[edited]
I'm not a lawyer (thank God!), but I'm pretty sure there is nothing
illegal about reverse engineering anything. Furthermore you can
patent certain methods of doing something, such as a machine or an
algorithm, but you *copyright* software, whether on disk or in ROM.
I don't think data formats are even protectable by *any* means unless
it does something other than merely transfer data, i.e., if it includes
a compression method (algorithm) of your own design, for example.
The mere act of reverse engineering itself is not illegal, but the
use to which you put the information gleaned *can* be infringement of
protected rights. Also, it makes a difference whether the information
from reverse engineering is used in an application for your gain (you
sell the application, for example) or if you simply use the information
for your own personal use. If you are really concerned about the
legality of what you do with the data, consult a lawyer.
Barry L. Lankford email: bar...@nuance.com Amateur Radio: N4MSJ
Madison, Alabama, USA ICBM: 34deg 41min 52.2sec N, 86deg 45min 34.2sec W
A P R Cooper
>From: bar...@nuance.com (Barry L. Lankford)
>Subject: Re: SSF to Rinex conversions.
>Date: Mon, 12 Jun 1995 08:51:57 GMT
>In article <3r9vvi$m...@deep.rsoft.bc.ca> ste...@mindlink.bc.ca writes:
>>> jo...@entc.tamu.edu (John Willis) writes:
>>>
>>> Does all this mean it is or is not illegal to simply read their
>>> binary files and write a basic binary to text decode program
>>> of exactly what's in there?
>>>
>>But, of course, reverse engineering would violate patents
>>and be illegal - oh, well!
>[edited]
>I'm not a lawyer (thank God!), but I'm pretty sure there is nothing
>illegal about reverse engineering anything. Furthermore you can
>patent certain methods of doing something, such as a machine or an
>algorithm, but you *copyright* software, whether on disk or in ROM.
>I don't think data formats are even protectable by *any* means unless
>it does something other than merely transfer data, i.e., if it includes
>a compression method (algorithm) of your own design, for example.
>The mere act of reverse engineering itself is not illegal, but the
>use to which you put the information gleaned *can* be infringement of
>protected rights. Also, it makes a difference whether the information
>from reverse engineering is used in an application for your gain (you
>sell the application, for example) or if you simply use the information
>for your own personal use. If you are really concerned about the
>legality of what you do with the data, consult a lawyer.
>Barry L. Lankford email: bar...@nuance.com Amateur Radio: N4MSJ
>Madison, Alabama, USA ICBM: 34deg 41min 52.2sec N, 86deg 45min 34.2sec W
Reverse engineering of software or data formats is specifically allowed under
European copyright legislation, provided that it is to provide functionality
not present in the original vendor's product.
A. Paul R. Cooper
British Antarctic Survey
ap...@pcmail.nerc-bas.ac.uk
***** Any opinions given here are my own, *****
***** and not necessarily those of British Antarctic Survey *****