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Just to be complete for others that visit this list, a full reference to 
the dissertation:
W.J. Pelgrum, "New Potential of Low-Frequency Radionavigation in the 
21st Century", Bussum, The Netherlands, November 2006, ISBN 
978-90-811198-1-8 (296p.).


Lu Abel wrote:
> Thanks, Nicol�s!   An impressive bit of work in Dr Pelgrum's thesis! 
>
> For those who don't want to read the whole 200 pages, the thesis is an 
> investigation of many aspects of improving Loran performance using 21st 
> century technologies -- for example, various sorts of signal processing 
> to eliminating noise and interference.   A major portion of the thesis 
> is devoted to the introduction of a non-traditional antenna for 
> receiving Loran signals (the equivalent of a "loop antenna" found in old 
> RDFs versus the whip antenna standard with traditional Loran 
> receivers).   These antennas are smaller (potentially allowing for a 
> "handheld" Loran) and have RDF capabilities (which in turn allows for an 
> Loran-based electronic compass as I speculated).  Many real world tests 
> were conducted with this new form of antenna, both comparing it to the 
> traditional whip antenna and demonstrating new capabilities such as a 
> Loran-based electronic compass as Nicol�s noted.
>
> Lu Abel
>
> Nicol�s de Hilster wrote:
>   
>> Please check http://jproc.ca/hyperbolic/loran_c_eloran.html
>>
>> At the bottom of that page you will find a link to a dissertation in 
>> which, on page 122, the LF H-field antenna is described. This loop 
>> antenna is not an omni-directional antenna and, when used in a dual loop 
>> configuration, can be used as a heading device. On page 168 in fig 5-49 
>> a graph is shown that, after calibration, compass errors are smaller 
>> than 0.8 degrees. On page 175 it reads "With only factory calibration, 
>> the Loran-derived compass heading had an offset of 2.8�, a standard 
>> deviation of 3.9�, and a 95% error of 8.3� with respect to the Vector 
>> Pro GPS compass. After field-calibration, these errors reduced to an 
>> offset of -0.1�, a standard deviation of 0.5�, and a 95% heading error 
>> of 1.1�...". The eLoran heading was checked against a Vector Pro GPS 
>> heading device (which is a zero-baseline RTK heading device) with an 
>> accuracy of 0.5 degrees.
>>
>> Nicol�s
>>
>>
>> Lu Abel wrote:
>>   
>>     
>>> A bit off topic, but ...
>>>
>>> A friend sent me an article (perhaps more accurately described as a 
>>> publicity release) about eLoran that claims its signal can be used in 
>>> electronic compasses.   The precise sentence in the article is:  
>>> "Moreover, eLORAN can do things GNSS cannot, such as acting as a static 
>>> compass."
>>>
>>> First of all, the statement about GPS is inaccurate, since one can buy 
>>> electronic compasses that work even when they are static by comparing 
>>> the phase differences between the receipt of GPS signals at two or three 
>>> antennas separated by a foot or less.
>>>
>>> What makes me very curious, though, is how an eLoran-based electronic 
>>> compass would work.  
>>>
>>> "GPS compasses" work by observing the phase differences between signals 
>>> received at two or three different receivers, these phase differences 
>>> give the direction to the satellite and by knowing its location in space 
>>> it's simple math from there to calculate the direction of true north.   
>>> But the phase difference method works only because GPS signals have such 
>>> a short wavelength that there are considerable phase differences between 
>>> signals received at antennas even a short distance apart.
>>>
>>> I have not been able to find any information on how eLoran-based 
>>> electronic compasses would work.   Loran signals are very 
>>> long-wavelength signals (25,000 times the wavelength of GPS signals), so 
>>> measuring their phase differences in any reasonably small electronic 
>>> compass setup would seem impractical.
>>>
>>> Maybe measure the bearing to each of the transmitters?   But I have a 
>>> hard time believing that could be done accurately enough to create an 
>>> electronic compass with sub-one-degree accuracy.
>>>
>>> Can anyone point me to an explanation, or is the sentence I quoted above 
>>> simply hyperbole from an eLoran supporter?
>>>
>>> Thanks
>>>
>>> Lu Abel
>>>
>>>     
>>>
>>>
>>>   
>>>     
>>>       
>>     
>>   
>>     
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>   


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