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> > I would like to know if each PRN will keep a stable relative location o=
f
> > the GPS constellation (comparing to the location of other satellites).
> > In other word, if an old satellite with PRN X was =A0decommissioned, wi=
ll
> > In other word, if an old satellite with PRN X was =A0decommissioned, wi=
> > a new satellite with the same PRN X, which will be launched in the
> > future into the constellation, be put into a spot that is very close to
> > its previously held spot? =A0 If so we may take advantage of it.
> > If the answer is yes, I also would like to know how close the new spot
> > relative to its previously held spot. A few kilometers or a few hundred
> > kilometers?
> > Thanks.
> > Johnson
> > future into the constellation, be put into a spot that is very close to
> > its previously held spot? =A0 If so we may take advantage of it.
> > If the answer is yes, I also would like to know how close the new spot
> > relative to its previously held spot. A few kilometers or a few hundred
> > kilometers?
> > Thanks.
> > Johnson
> The PRN number and the satellite position in space are unrelated.
> Since PRN numbers can be reassigned from the ground at any time, they
> could be anywhere in the constellation. =A0The practice is to keep a PRN
> number with a satellite for it's lifetime, but there is no guarantee
> that when a satellite dies, it's PRN number will be in the same
> orbital slot. =A0Don't count on it being in the same spot!
> Since PRN numbers can be reassigned from the ground at any time, they
> could be anywhere in the constellation. =A0The practice is to keep a PRN
> number with a satellite for it's lifetime, but there is no guarantee
> that when a satellite dies, it's PRN number will be in the same
> orbital slot. =A0Don't count on it being in the same spot!
About a third of the satellites are visible at any given time. Might
it be that PRN's are distributed in a manner to minimize cross
correlation problems that could impede satellite acquisition?
--- CHAS
On 10-04-18 15:50 , HIPAR wrote:
>>> I would like to know if each PRN will keep a stable relative location of
>>> the GPS constellation (comparing to the location of other satellites).
>>> In other word, if an old satellite with PRN X was decommissioned, will
>>> a new satellite with the same PRN X, which will be launched in the
>>> future into the constellation, be put into a spot that is very close to
>>> its previously held spot? If so we may take advantage of it.
>>> If the answer is yes, I also would like to know how close the new spot
>>> relative to its previously held spot. A few kilometers or a few hundred
>>> kilometers?
>>> Thanks.
>>> Johnson
>>> the GPS constellation (comparing to the location of other satellites).
>>> In other word, if an old satellite with PRN X was decommissioned, will
>>> a new satellite with the same PRN X, which will be launched in the
>>> future into the constellation, be put into a spot that is very close to
>>> its previously held spot? If so we may take advantage of it.
>>> If the answer is yes, I also would like to know how close the new spot
>>> relative to its previously held spot. A few kilometers or a few hundred
>>> kilometers?
>>> Thanks.
>>> Johnson
>> The PRN number and the satellite position in space are unrelated.
>> Since PRN numbers can be reassigned from the ground at any time, they
>> could be anywhere in the constellation. The practice is to keep a PRN
>> number with a satellite for it's lifetime, but there is no guarantee
>> that when a satellite dies, it's PRN number will be in the same
>> orbital slot. Don't count on it being in the same spot!
>> Since PRN numbers can be reassigned from the ground at any time, they
>> could be anywhere in the constellation. The practice is to keep a PRN
>> number with a satellite for it's lifetime, but there is no guarantee
>> that when a satellite dies, it's PRN number will be in the same
>> orbital slot. Don't count on it being in the same spot!
> About a third of the satellites are visible at any given time. Might
> it be that PRN's are distributed in a manner to minimize cross
> correlation problems that could impede satellite acquisition?
> it be that PRN's are distributed in a manner to minimize cross
> correlation problems that could impede satellite acquisition?
Each PRN code is 1023 bits long - enough to make mistaken correlation
very unlikely.
However, "hi sensitivity" receivers are more likely to lock onto what
seems to be valid and that could be a different satellite (or just
noise) for a brief period. Maybe.
--
gmail originated posts are filtered due to spam.
T Driver wrote:
>> I would like to know if each PRN will keep a stable relative location of
>> the GPS constellation (comparing to the location of other satellites).
>> In other word, if an old satellite with PRN X was decommissioned, will
>> a new satellite with the same PRN X, which will be launched in the
>> future into the constellation, be put into a spot that is very close to
>> its previously held spot? If so we may take advantage of it.
>> If the answer is yes, I also would like to know how close the new spot
>> relative to its previously held spot. A few kilometers or a few hundred
>> kilometers?
>> Thanks.
>> Johnson
>> the GPS constellation (comparing to the location of other satellites).
>> In other word, if an old satellite with PRN X was decommissioned, will
>> a new satellite with the same PRN X, which will be launched in the
>> future into the constellation, be put into a spot that is very close to
>> its previously held spot? If so we may take advantage of it.
>> If the answer is yes, I also would like to know how close the new spot
>> relative to its previously held spot. A few kilometers or a few hundred
>> kilometers?
>> Thanks.
>> Johnson
>
> The PRN number and the satellite position in space are unrelated.
> Since PRN numbers can be reassigned from the ground at any time, they
> could be anywhere in the constellation. The practice is to keep a PRN
> number with a satellite for it's lifetime, but there is no guarantee
> that when a satellite dies, it's PRN number will be in the same
> orbital slot. Don't count on it being in the same spot!
You are definitely right! Thanks.
> The PRN number and the satellite position in space are unrelated.
> Since PRN numbers can be reassigned from the ground at any time, they
> could be anywhere in the constellation. The practice is to keep a PRN
> number with a satellite for it's lifetime, but there is no guarantee
> that when a satellite dies, it's PRN number will be in the same
> orbital slot. Don't count on it being in the same spot!
