| Date: | 2009-04-10 10:30:00 | |
| Sender: | Nakamura Shinichi <slrmail@dgfi3.dgfi.badw-muenchen.de> | |
| Subject: | [SLR-Mail] No. 1764: ILRS / NEWG - OICETS Prediction Quality | |
| Author: | Nakamura Shinichi | |
| Content: | ******************************************************************************** SLR Electronic Mail 2009-04-10 10:30:00 UTC Message No. 1764 ******************************************************************************** Author: Nakamura Shinichi Subject: ILRS / NEWG - OICETS Prediction Quality Dear Colleagues, We apologize for the inconvenience this bad CPF may cause. JAXA calculated CPF based on RARR (range and range rate) by tracking stations, i.e., not SLR stations. Thus, CPF has big error. Please understand our circumstances. We will concern about accuracy of CPF. We will check accuracy and quality of CPF for OICETS. Best Regards, Shinichi Georg Kirchner wrote: > Dear colleagues, > > you are all listed as OICET contact points on the ILRS pages, and we > have a problem for the OICET predictions ... > > We have several complaints from SLR stations about a rather low quality > of OICET predictions (CPF for SLR); > Time Bias values are mostly big, reaching up to +- 200 ms; Range Bias > values are also 100 m or more. > > Such large offsets make it difficult for most stations to get any > returns, especially in daylight; > the consequence is in many cases that observers / stations stop tracking > OICET at all, preferring to track other targets etc., thus significantly > reducing the available OICET SLR data. > > I am sure you are aware that the prediction quality for nearly ALL > satellites has been improved significantly with the use of CPF data; in > almost all cases, time biases are only a few milliseconds, and range > biases are also close to zero. > > Could you please check the situation with OICET, and / or forward the > mail to the involved persons ! > > Thank you for any information / action ! > > Best regards, > > Georg > > who is aware that this week might be mainly a holiday week all over the > world :-) > -- *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* Shinichi Nakamura Japan Aerospace Exploration Agency(JAXA) Precise Orbit Determination Team tel +81-29-868-2625 fax +81-29-868-2990 JAXA SLR Homepage http://god.tksc.jaxa.jp From: slrmail@dgfi3.dgfi.badw-muenchen.de ******************************************************************************** |