Subject: [SLR-Mail] No. 866: Glonass CCR information update From: H.Kunimori > ******************************************************************************** SLR Electronic Mail 2001-12-22 10:46:00 UTC Message No. 866 ******************************************************************************** Author: H.Kunimori Subject: Glonass CCR information update Subject: Glonass CCR information update Subject: Glonass Subject: Glonass CCR information update Folks, Based on Vladimir Vasiliev input to Mission WG, Glonass CCR array information updated now on the WEB http://ilrs.gsfc.nasa.gov/glonass.html in which there are different type of array drawings including one of the most recent launch in December 2001. Please note that in the previous version of this page, there was old description of Center of Mass correction in: http://www.mcc.rsa.ru/IACKVO/igex98.htm where Center of Mass correction to panel of retroreflectors was Xbf : -1510 mm This value was outdated and should be updated as below, please refer to the following discussion among MWG members. With my apology of late upload of this. Best regards, Hiroo Kunimori, Mission Working Group ----- From: ”Vladimir Vasiliev” To: ”Hiroo Kunimori” Subject: Glonass Date: Wed, 12 Dec 2001 10:12:46 +0300 Dear Hiroo, As I reported in October 2000, the correct value for the maximum effective offset between the CoM and the effective reflection plane (taking into account the light propagation in glass) is 1.5416 m (in may be 1.5417 - this is within my estimation error). There is a dependence of the effective offset value on the observation angle, giving approximately 1.5000 to 1.5416 m for the full range of angles, which may be easily calculated for any particularly angle. The previous 1.510 m value from the web-site was a preliminary estimate and should be corrected. Let me remind you that we already had an e-mail discussion of the matter with MWG in mid-October 2000. Please find this enclosed. Best regards, Vladimir --- Dear Colleagues, The figure 1.5416 m is correct. There is of course a dependence of the effective offset value on the observation angle (approx. 1.5000 to 1.5416 for the full range of angles), which may be easily calculated. Best regards, V. Vasiliev ---------- > Dear Dr. V. Vassilyev, > > We participated to the IGEX-98 campaign with our Lunar Laser Ranging station > for tracking the GLONASS satellites. We have contributed to the validation of > radiotracking orbits by laser observations. > Recently, we had again some discussions about the corrections to be applied to > the laser range measurements to get the correct position of the center of mass of > the satellite. Indeed, we have an e-mail from you (Oct. 9, 99) to Dr. H. > Kunimori. This e-mail is clear, consistent and yields corrections of about 1.5416 > meters (1.5695 - the light travel inside the retroreflectors (0.0191x1.46)). > But, as you know, there is also an information on the web site: > http://ilrs.gsfc.nasa.gov/glonass.html referring to a Russian site which proposes a > global correction of 1.510 meter between the center of mass and the effective > reflection plane. It seems not consistent with your e-mail by about 3-4 > centimeters. Could you confirm the values you gave in your e-mail or make to > us some suggestions concerning this correction. > With many thanks. > > Best regards > > F. Barlier, Ch. Berger =============================================================== Hiroo Kunimori Coordinator, Mission Working Group, ILRS (International Laser Tracking Service) Keystone Project Group, Communications Research Laboratory 4-2-1 Nukui-Kita Koganei, Tokyo 184-8795 Japan Tel:81-423-27-7559,Fax:81-423-27-6077 E-mail:kuni@crl.go.jp From: Hiroo Kunimori From: ”Vladimir Vasiliev” ********************************************************************************