Center for Space Debris Data Collection, Processing and Analysis
Keldysh Institute of Applied Mathematics (KIAM)
Russian Academy of Sciences
4 Miusskaya Sq., Moscow, 125047 Russia
High Geocentric Orbit Space Debris Circular No.3
Efraim L. Akim KIAM Deputy Director
Coverage period ends on Mar 31, 2007
© Keldysh Institute of Applied Mathematics
This circular opens a new series of publications devoted to periodically summarizing the worldwide scientific activities in observations of space debris objects on high geocentric orbits (GEO, HEO and high near-circular non-GEO). Objects considered to be included into this publication are fragments (operational by nature, created in fragmentation events or as a result of larger objects’ surface and construction deterioration due to environment conditions) having brightness fainter than 15th visual magnitude during most part of their observation time. This limit corresponds to approximately 1 m size object on geostationary orbit. It is possible that sometimes these objects can be brighter than 15th magnitude due to combination of their specific properties (surface reflectivity and attitude) and favorable observation conditions (good phase angle, high elevation etc.).
The goal of this publication is to give the world scientific community imagination about the status of high geocentric orbit space debris researches and to provide up to date data for each discovered object including orbital parameters, estimated standard magnitude and estimated area-to-mass ratio value. Those data can be included in existing space debris models as well as can be used for study of long-term orbital evolution and possible origin of the objects. The Circular will also serve as some reference document for scientists and amateurs involved in those objects observations and data analysis. Operators of spacecraft in high geocentric orbits (mainly in GEO) can use this publication in order to obtain a more realistic description of the situation around their orbital assets.
Observation planning, ephemeris support, processing and analysis of obtained data are made by researchers from Keldysh Institute of Applied Mathematics (KIAM) (Vladimir Agapov, Igor Molotov, Viktor Stepanyants, Vladimir Titenko) with invaluable help of Zakhariy Khutorovskiy (Vympel Corporation) and Vasiliy Yurasov (Institute for Precision Instrument Engineering, IPIE).
The presented results include discoveries stemming from surveys of the European Space Agency (ESA) utilizing the ESA Space Debris Telescope in Tenerife. Those surveys and all follow-up observations from the ZIMLAT telescope of the Astronomical Institute of the University of Bern in Switzerland (AIUB) are planned, run, processed, and analyzed by the AIUB.
All questions regarding cooperation in the joint research program for high geocentric orbit space debris studies should be sent to Prof. E. L. Akim, KIAM Deputy Director. All questions regarding observation schedule, required formats, ephemeris support, observations and orbital data processing, analysis and usage should be sent to Dr. V. M. Agapov. All questions regarding requirements for observation instruments, CCD frame processing software, possible help in the instrumentation upgrade in order to make possible participation in the research program should be sent to Dr. I. Ye. Molotov.
List of sensors
This list includes all sensors participating today in a joint program of observation and analysis of space debris objects on high geocentric orbits. Each sensor has its own identification number assigned in the KIAM space objects database. Most of the sensors are involved in minor planet observations as well, thus having the MPC-assigned identification code. But for the purpose of this research program it was decided to maintain a separate ID system permitting to describe all participating sensors regardless of their involvement in other research programs. Coordinates of sensors are given for reference purposes only and should not be used in real observation processing. In the column “Instrument”, the common name, aperture (d, mm) and focal length (f, mm) of each instrument are given.
The list will be updated each time a new sensor will send observations for objects studied.
Table 1. List of participating sensors
Note. The focal lengths value for ZIMLAT (Zimmerwald) and OGS (Teide) telescopes had been modified in this table in order to present "effective focal lengths" including the focal reducer optics as for the other telescopes. The original values published for these telescopes in the previous issues of the Circular were the focal lengths of the main telescope optics.
This section contains information on the objects newly discovered during the period Mar 1 – Mar 31, 2007.
There are two lists. The first one contains information on objects which have been successfully recovered in follow-up observations after initial detection and one-night tracking and for which orbital data and area-to-mass ratio (AMR) value have been determined with high level of confidence. The second one contains information on objects having only one-night track of observations. A complete set of orbital data cannot be determined for these objects. Only some orbital parameters (mainly inclination and RAAN) are determined relatively accurately. The AMR values cannot be determined for these objects at all.
It should be noted that all one-night tracks have been tested to identify them with all other one-night tracks and with all known objects in the KIAM database having well determined orbits (both bright and faint). It is possible that the identification failed not only due to the absence of other tracks of the same object, but also due to uncertainty caused by an unknown AMR value which can result in very significant orbital evolution that prevents proper correlation of one-night tracks.
Each object listed in this section has two identifiers. The first one (column ID2 in the table below) is assigned by the observer who discovered the object and the second one (ID1) is assigned in the KIAM space objects database. Since no commonly agreed space debris identification system exists yet all identifiers provided can be regarded as temporary ones. As soon as such a system will be agreed upon, all objects will be assigned with the new identifiers.
Orbital elements are referring to True Equator Mean Equinox (TEME) coordinate system. Area-to-mass ratios are calculated assuming reflectivity coefficient equal to 1.3. Orbital elements for short tracks (Table 3) are obtained in two steps. In the first step an attempt is made to determine an orbit with zero eccentricity. In case of large residuals (more than the expected 3- sigma) the second step is applied. At this step the eccentricity is also estimated.
Table 2. List of newly discovered and confirmed objects
Table 3. List of newly discovered objects having only single one-night track of observations
This section contains information on successful identification of newly and previously obtained single one-night tracks with each other as well as with objects having well determined orbits.
Table 4. New identifications
This section contains information on the latest orbital updates for objects discovered prior to Mar 1, 2007 and observed at least once in Mar 2007 or for which the latest orbital update was not published in the previous issues. 51 of previously discovered objects in total are observed in Mar 2007.
Table 5. Updated orbital parameters for objects observed in Mar 2007.
Master list of objects
The master list of objects includes all high altitude orbit faint objects discovered up today, with a description of the circumstances of the discovery and the last update of orbital information. Due to the large volume of the master list it will be distributed separately in electronic form only.
This section contains general statistics on obtained measurements. It should be noted that additional portions of measurements obtained in Jan-Feb had been processed in March so the overall number of measurements includes those ones.
Table 6. Distribution of measurements obtained by each facility by year of observation (as of Mar 31, 2007)
Table 7. Observation statistics for Mar 2007
We would like to express our appreciation to Rudiger Jehn (European Space Operations Center), Vladimir Kouprianov (Pulkovo Observatory), Vasiliy Rumyantsev (Crimean Astrophysical Observatory), Thomas Schildkneht (Astronomical Institute of the University of Bern) and Vasiliy Yurasov (Institute for Precision Instrument Engineering, IPIE) for their comments and suggestions aimed to the Circular improvement.
17 ìàÿ 2007.