[clug] GPS, GIS, GTS, SDI and FOSS

[Scott Ferguson]

On Thu, 03 Mar 2011 11:04:40 +1100 Robert Edwards wrote:
>
> On 03/03/11 10:34, Scott Ferguson wrote:
>> > On 03/03/11 07:21, Brad Hards wrote:
>>> >> On Thursday, March 03, 2011 12:27:51 am Scott Ferguson wrote:
>>>> >>> * Another solution to ionospheric distortion is internet sourced
>>>> >>> corrective data - any suggestions/experience there?
>>>> >>> A local base station is unlikely to work due to the local topography.
>>> >> I wouldn't have expected that there would be much variation in ionospheric
>>> >> delay across the ACT (or anywhere roughly north / south). The variation is
>>> >> strongest at dawn / dusk. Can you just put something on the roof?
>>> >>
>>> >> Brad
>>> >>
>>> >>
>> >

<snipped>

>> >
>> > Not sure what you mean by "put something on the roof"... antennae?  If
>> > so it is a means of reducing signal reflection - doesn't correct for
>> > lens effects.
>> >
>> > I'm happy to discuss this further, time allowing, especially as it is a
>> > learning curve for me, but probably best either off-list or under an
>> > [OT] prefaced subject-line (lest I become a hypocrite!)
>> >
>> > Cheers
>> >
> Lets keep this on the list for a little longer...

Done

> 
> I think Brad was suggesting building your own base-station with an
> antennae in a fixed location (on the roof). Then you can derive your
> own differential data and either transfer it to the GPS you are trying
> to correct for (eg. over 3G?) OR use your differential data to correct
> the data you have collected in a post-processing step, by aligning the
> time-stamps etc.
> 
> Cheers,
> 
> Bob Edwards.
> 
> 

Understood, thanks (both of you)

Post-processing is something I want to avoid if at all possible. I'm
fairly certain I can get away with that as I don't require that high a
level of accuracy.

Though a lot of the needs are for data collection by location - for
which post processing is OK, some are for direction and steering - and
when botanical localities are within 3 metres of each other that could
lead to problems (costs, damage, wasted time).

Cheers