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spaces ILRS Home arrow Data & Products arrow Predictions arrow Prediction Survey arrow Prediction Survey of Sites, July 2004 spaces
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Jul 2004 Responses
May 2002 Responses
Aug 2001 Responses
   

Prediction Survey of Sites

As of July 2004

Site
ID
AJI
BEC
CHA
GPB
GRA
ENV
ERS
ETA
GFO
GLO
GPS
ICE
JAS
LAG
LAR
MET
STA
STE
TOP
Drag?
Access
Golosiiv 1824                                          
Lviv 1831
H
H
H
H
H
H
 
H
H
H
H
H
N/A
ftp
Maidanak 1 1863                                          
Maidanak 2 1864                                          
Komsomolsk 1868                                          
Mendeleevo 1870                                          
Simeiz 1873                                          
Riga 1884
H
H
G
H
G
H
H
H
H
H
H
H
H
H
H
Yes
email
Katsively 1893                                          
McDonald 7080
H
H
G
H
G
H
H
H
H
H
H
U
H
H
H
H
H
H
H
No
ftp
Yarragadee 7090
H
H
G
H
G
E
H
H
S
N
N
H
H
H
H
H
H
H
Yes
email/ftp
Greenbelt 7105
H
H
G
H
G
H
H
H
H
H
H
H
H
H
H
H
H
H
H
Yes
ftp
Monument Peak 7110
H
H
G
H
G
H
H
H
H
H
H
H
H
H
H
H
H
H
H
Yes
ftp
Tahiti 7124
H
H
G
H
G
H
H
H
H
H
H
H
H
Yes
ftp
Wuhan 7231                                          
Changchun 7237
H
H
G
H
G
H
H
H
H
H
H
H
H
H
H
H
H
H
?
ftp
Beijing 7249
H
H
G
H
G
H
H
H
H
H
H
H
H
H
H
H
H
H
Yes
ftp
Koganei 7308                                          
Arequipa 7403
H
H
G
  
G
H
H
  
H
      
H
H
H
H
H
H
H
Yes
ftp
Concepcion 7405
H
H
G
H
G
E
G
H
H
N
N
H
N
H
H
H
H
H
Yes
email
Hartebeesthoek 7501
H
H
G
H
G
H
H
H
H
H
H
H
H
H
H
H
H
H
Yes
ftp
Metsahovi2 7806
N
N
N
N
N
N
N
  
N
      
N
N
N
N
N
N
N
No
ftp
Zimmerwald 7810
H
H
G
H
G
E
G
H
S
C
C
U
H
H
H
H
H
H
H
Yes
email
Borowiec 7811
H
H
G
G
H
H
H
 
H
H
H
H
H
H
No
email
Kunming 7820                                          
San Fernando 7824
H
H
G
H
G
H
H
H
 
H
H
H
H
H
H
H
No
email
Mt. Stromlo 7825
H
H
G
H
G
H
H
H
H
H
H
H
H
H
H
H
H
H
No
ftp
Helwan
7831
H
H
G
H
G
H
H
H
 
H
H
H
H
H
H
H
No
ftp
Riyadh 7832
H
H
G
G
H
H
H
H
H
H
H
H
H
H
H
H
H
Yes
ftp
Grasse 7835
H
H
G
  
G
H
H
  
H
      
H
H
H
H
H
H
H
No
email/ftp
Potsdam 7836
H
H
G
H
G
HN
HG
H
H
HN
H
H
H
H
H
H
H
H
H
Yes
ftp
Shanghai 7837                                          
Simosato 7838
H
H
G
H
G
H
H
H
H
H
H
H
H
H
H
H
H
H
Yes
email
Graz
7839
HN
HN
G
H
G
EH
GH
HN
HNS
NH
NH
U
H
HN
HM
H
HN
HN
HN
Yes
ftp
Herstmonceux 7840
HNJ
HN
G
H
G
NEH
GH
HN
SNH
CH
CH
HN
HN
HMN
SMH
HN
HN
HN
Yes
email
Potsdam 7841
H
H
G
H
G
HN
HG
H
H
HN
H
H
H
H
H
H
H
H
H
Yes
ftp
Grasse (LLR) 7845
H
H
G
  
G
H
H
  
H
H
H
  
H
H
H
H
H
H
H
No
email/ftp
Matera 7941
H
H
G
H
G
H
H
H
H
H
H
H
H
H
H
H
H
H
No
ftp
Wettzell
8834
HN
H
G
G
H
G
HN
HN
HN
H
  
HN
HN
H
H
HN
HN
HN
Yes
ftp
FTLRS --
H
H
G
  
G
H
H
  
H
      
H
H
H
H
H
H
H
No
email/ftp
TROS --                                          

 

Satellite abbreviations: AJI Ajisai   GPS GPS-35/36
  BEC BE-C   ICE ICESat
  CHA CHAMP   JAS Jason-1
  GPB GP-B   LAG LAGEOS-1/2
  GRA GRACE-A/B   LAR Larets
  ENV Envisat   MET Meteor-3M
  ERS ERS-2   STA Starlette
  ETA Etalon-1/2   STE Stella
  GFO GFO-1   TOP TOPEX
  GLO GLONASS      
           
Prediction Provider codes: C CODE-based      
  E ESOC      
  G GFZ      
  H HTSI      
  J JAXA      
  M MCC      
  N NGSF      
  S GSFC 926      
  U U. Texas/CSR      

General Comments:

  • I think the ILRS must take into consideration that there are new observers for satellite using SLR and must plan a training period for them, in one of the countries which have SLR station. (Magdy I. El-Saftawy/Helwan)
  • Sometimes [ we have problems acquiring satellites]; we get about 50-70% only of CHAMP passes; when the predicted and actual TB are differing too much (more than some 10 ms), we have only a < 50% chance to get it ... (Georg Kirchner/Graz)
  • TB for some satellites (CHAMP, GRACE-A/-B) sometimes not well defined; causes problems. (Georg Kirchner/Graz)
  • NPs available at CDDIS are only occasionally younger than 4 or 5 hours; but this might be more a problem on the station side (including Graz :-( - but we are working on it ....); (Georg Kirchner/Graz)
  • Often acquisition problems with Champ, Envisat, Grace, Icesat, GP-B. Time biases of several tens of milliseconds are very difficult for us to handle, especially during day light. (Werner Gurtner/Zimmerwald)
  • Sometimes [we have problems acquiring satellites] (Stanislaw Schillak/Borowiec)
  • Some time there are problems to get the satellite if blind or day-time ranging( Kazimirs Lapushka/Riga)
  • Since we have been concentrating on calibration targets we have limited experience with very low LEOs, but no problems as far as we can tell. The process seems to be working OK. We are working towards re-automating the download of predictions at our end. (Christopher Moore/Mt. Stromlo)
  • I am a little worried about the recently very poor prediction quality for Gravity Probe B. Two consecutive prediction sets from HTSI (August 14, 15)
    resulted in time biases of -150 and +150 ms, respectively. Without optical control this poor prediction quality rules out daylight acquisition of this satellite. I see no reason for such problems; GP-B is told to carry GPS onboard and is not an extremely LEO. GFZ is doing much better with CHAMP and GRACE. There is a slight problem in the naming convention of the prediction files on
    the CDDIS FTP server. In case one is using a DOS-based FTP process for acquisition of predictions, for the GLONASS satellites the full naming (e.g. Glonass84_ephemeris_040814.htsi) exceeds the 8.3 DOS style for file denomination. In this case overwriting will occur (according to the unavoidable file name truncation) and only the GLONASS set with the highest number (usually Glonass89) will be present. EDC prevents this effect by renaming the HTSI files before putting them on the server (instead of "Glonass84_ephemeris_040814.htsi" you find at EDC "g84_0408.14"). This is much more user-friendly. (Ludwig Grunwaldt/Potsdam)
  • We often refer to the following page when acquiring the satellites is difficult: http://aiuas3.unibe.ch/cgi-bin/cgi-time_bias. (Tadashi Ishikawa)
  • I'll have to ask the crew, but I haven't had any complaints. Part of our system hardware does not deal well with really short ranges, and these passes are short anyway, making acquisition harder than than other satellites with even the best of predictions. (Randy Ricklefs/MLRS)
  • No we do not experience any problems other than with GLONASS satellites in the day and GPS satellites during day and night times, We have longer than normal aquisition times in the case of our new SLR staff members currently under going training. (Johan Bernhardt/Hartebeesthoek)
  • We have acquisition problems with regards to CHAMP and Meteor-3M. (Roy/SALRO)
  • Occasionally only one or two satellite predictions have a large time bias. (Cunbo/Changchun)
  • Meteor-3M and GRACE-A/B give us tracking problems. (MLRO)
  • We do not have problems acquiring satellites except for GP-B. The process is working well that the CHAMP predictions are not good enough for us to track the satellite. (Piironen/Metsahovi)
  • Normally no problems except for sometimes on GRACE or CHAMP (Pierron/Grasse)

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Last modified date: Wednesday, December 01, 2004
Author: Carey Noll
Maintained by: Carey Noll

 
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