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Fig. 1: Podëbrady Transmitter DGPS Modulator
The Czech Army SFOR troops tested the LW DGPS receiver in
Bosnia, with 3 - 6 m accuracy.
Successful experiments were carried out in the Netherlands,
Noordwijk, but there is no notice on accuracy there.
Our colleagues from Poland also did some experiments.
The Czech Army tested LW receivers connected with high
quality GPS receivers. The obtained accuracy is 20 centimetres
- but with 50% probability.
The problem is the lack of financial means which causes
discontinuity in correction transmission, even if the Ministry of
Transport of the Czech Republic is interested in the use of LW
corrections for the determination of train positions on regional
railways, and Ministry of Defence also promised a support.
The LW technology of correction dissemination may be
regarded as the promising one for CEI countries, as there are
several unused LW transmitters on the territories of the former
Soviet block, and this technology does not require large
investments.
3. EXPERIMENTS AT FAAKER SEE (VILLACH)
A place near the shore of the Faaker See, a lake near Villach (in
Austria on the border with Italy and Slovenia) was chosen for
our experiments, where ALF (from Frankfurt am Main) and
DARC (from Villach) diffused DGPS corrections had already
been received, and where we hoped to receive LW from
Podebrady signal too. It was luckily possible.
During the first session of our experiments (Nov 24th 1999), we
determined the coordinates of a reference point for our
experiments from an L1/L2 baseline solution from Trieste (100
Km away), where we have our Master station on the roof of the
Department of Civil Engineering, using Trimble 4000SSE
receivers. We got the result from a lono free-float solution
(GPSurvey software).
❖ ALF Transmitter
, FaakerSee: test site
Fig. 2: RTCM correction sources tested in our experiments
