[time-nuts] Re: looking for MITREX modem manual/documentation

[Lux, Jim]

On 3/25/22 5:55 AM, jeanmichel.friedt at femto-st.fr wrote:
> Dear community,
> I am trying to find historical documents describing the pseudo random sequences used
> in the SATRE Two-Way Satellite Time and Frequency Transfer (TWSTFT) modem.
> K. Imamura & F. Takahashi (Two Way Time Transfer Via a Geostationnary Satellite,
> J. of the Comm. Research Lab., 39(1), March 1992) describe the code structure
> (14-bit long pseudo random sequence truncated to 10000 bit length) but the
> generator polynomial coefficients are not given. I have not been able to find this
> information in Timetech's SATRE manual nor in the publicly available literature.
> This paper cites "P. Hartl, A modem for microwave time and ranging experiments
> via telecommunication satellites, MITREX2500 Manual, Jan 1989" which I am unable
> to locate.
> Would anyone have such a document, or at least could tell me whether the generator
> polynomials are described there? Alternatively, does anyone have a description of these
> 14-bit polynomial generators?
>
> Thanks, Jean-Michel
>
> --
> JM Friedt, FEMTO-ST Time & Frequency, 26 rue de l'Epitaphe, 25000 Besancon, France
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I ran across this:
https://ieeexplore.ieee.org/document/5168259


  SATER modem used in microwave time transfer

but it's only 2 pages and not very informative.


A paper by Hartl, et al.

https://doi.org/10.1016/0094-5765(85)90134-1 
<https://doi.org/10.1016/0094-5765(85)90134-1>

Cites a paper for the MITREX modem, but also mentions it can do two PN 
sequences at the same time.
P. Hartl et al., High accuracy global time transfer via geo-
synchronous telecommunication satellites with MITREX " Z. FLugwiss., 
Weltraumforschung, v7, pp 334-342, 1983


https://ui.adsabs.harvard.edu/abs/1983ZFlWe...7..335H/abstract

1983ZFlWe...7..335H


Hartl has had a paper at PTTI in Dec 1983 "Spread spectrum time transfer 
experiment via INTELSAT"

There's also P. Hartl, et al., Mitrex 25000 documentation, Institute for 
Navigation, Univ. Stuttgart, Germany, Jan 1985


Looks like it was probably built at Univ Stuttgart:
https://www.ins.uni-stuttgart.de/institut/geschichte/

Im Jahr 1983 wurde Professor Dr.-Ing. Philipp Hartl auf die Professur 
berufen und übernahm die Leitung des Instituts. Während der Amtszeit von 
Prof. Hartl wurden insbesondere die Forschungsbereiche der 
Satellitenmesstechnik sowie der Satellitenfernerkundung aufgebaut. 
Hervorzuheben sind die Konzeption und Entwicklung des 
Satellitenmesssystems PRARE, des Zeitübertragungssystems MITREX sowie 
die grundlegenden Arbeiten zur Radar-Interferometrie.