DANEOPS Home Page


DLR-Archenhold Near Earth Objects Precovery Survey (DANEOPS)

The DANEOPS project has been initiated to systematically search existing photographic plate archives for precovery images of known NEOs.

It is organized as a cooperation between Gerhard Hahn, DLR Institute of Space Sensor Technology and Planetary Exploration and Andreas Doppler and Arno Gnädig, from an amateur working group at the Archenhold Observatory. Since November 1999 Matthias Busch and Reiner Stoss from the amateur group at the Starkenburg Observatory are participating with recovery observations.

Through a cooperation with the Uppsala Astronomical Observatory, in course of U.D.A.S., the Uppsala-DLR-Asteroid-Survey Project, recovery observations are made with the 1m Schmidt telescope in Kvistaberg, in response to DANEOPS predictions.

The available digitized sky survey archive logs are searched for plates which could contain images of known NEOs. At the moment digitized images from the Palomar Observatory Sky Survey (POSS) - 1.2m Oschin Schmidt, and from the Anglo-Australian Observatory - 1.2m UK-Schmidt are used, i.e. we use DSS 1 and 2 from the STScI Digitized Sky Survey These data are copyrighted material. See their proper acknowledgements.

Through the webinterface of Skymorph we can access the digital archive of the JPL/NEAT programme after searching their image logfile to make predictions. All successful precoveries found in this way are presented as animations on the corresponding asteroids page (see below).

Similarily, we search the archive of the Canada-France-Hawaii Telescope (CFHT) to identify predicted NEO trail on the images of the CFH12k Camera.

Recently we got access to part of the ESO Schmidt plate archive, in digitized form, from archive tapes kindly provided by the former Astronomical Institute of the University of Münster.

We routinely use the excellent website of the USNO Flagstaff Station Integrated Image and Catalogue Archive Service and acknowledge these services thankfully.


Since it is not possible for us to identify the names of the observers who took the original Schmidt plates we would like to acknowledge anonymously all of them here, and explicitly stress that we only do have access to the digitized frames, which do not contain the relevant information.

Fully perturbed n-body ephemeris calculations based on the current osculating orbital elements are generated over a period of 50 years and checked for presumptive images. Specially developed software by Andreas Doppler and Arno Gnädig performs this task.

The retrieved images are checked and compared with the predicted trails in both length and orientation. The successfully identified images are then measured astrometrically, again with special software developed by Arno Gnädig. The USNO SA2.0 catalogue is used as reference.

As a rule, the obtained positions will be checked with an orbit improvement routine prior to its submission to the MPC.

This procedure will be used for all known, and continously applied to newly discovered NEOs, on a routine basis, allowing a rapid check for precovery images.


This is an attempt to actively contribute to the Spaceguard Survey, and it is hoped to get access to additional plate archives in the future. Furthermore we plan to perform recovery observations based on predictions from improved ephemerides in order to verify uncertain archive identifications.


Other groups working on a similar program:

ANEOPP the Arcetri Near Earth Object Precovery Program


DANEOPS Team

at DLR Berlin-Adlershof

  • Gerhard Hahn
  • Anders Erikson
  • Stefano Mottola
  • Martin Hoffmann

    at Archenhold Observatory

  • Andreas Doppler
  • Arno Gnädig

    at Starkenburg Observatory

  • Matthias Busch
  • Reiner Stoss

    at Uppsala Observatory

  • Claes-Ingvar Lagerkvist
  • Tarmo Oja
  • Johan Warell
  • Ola Karlsson

    Through a cooperation with Rob McNaught at Siding Spring Observatory we get direct access to the locally available UK Schmidt plates. Rob is checking predicted plates on our request and performs the necessary measurements at the spot.


    Observing campaigns:

    In June 2001, we got access to the 1.5m Spanish telescope at Calar Alto (through a cooperation with Thomas Müller and Rainer Kresken from ESA) which allowed us to perform dedicated recovery and follow-up observations of NEOs. A detailed report about this campaign and its results can be found here: Calar Alto campaign (recently updated and extensively illustrated and commented by Arno Gnädig)


    Successfully precovered/recovered asteroids:

    (in chronological order of their precovery)

    Atens, Apollos, Amors

    1999 LT7 , 1999 AN10 , 1999 GK4 , 1998 WQ5 , 1998 XM4 , 1998 MQ ,

    1999 LO28 , 1997 SE5 , 1999 NC5 , 1998 SO10 , 1998 MT24 , 1998 UO1 ,

    1997 GH28 , 1999 JD6 , 1999 JB , 1999 VL12 , 1999 WK13 , 2000 BD19 ,

    2000 BJ19 , 2000 DN8 , 2000 AF6 , 2000 DK79 , 2000 ES70 , 1998 XA5 ,

    1999 RH27 , 2000 DM8 , 2000 ET70 , 2000 GD2 , 2000 LC16 , 2000 NL10 ,

    2000 PJ6 , 1999 TX16 , 2000 PN9 , 2000 QL7 , 2000 LM , 1998 MR24 ,

    2000 QJ1 , 1999 FA , 1999 YN4 , 2000 HW23 , 2000 SQ43 , 1999 XP35 ,

    1999 HV1 , 2000 AE6 , 2000 YK29 , 2000 YL29 , 2000 XH44 , 2000 YJ66 ,

    1990 TG1 , 2001 AE2 , 2001 BW15 , 2000 OG , 2001 CB32 , 2000 SA10 ,

    2001 EB , 2001 DU8 , 2000 UR13 , 2001 FD7 , 2000 WK63 , 2001 GN2 ,

    2000 QU7 , 2000 YN29 , 2001 FM129 , 2001 LF , 2001 MZ7 , 2001 KZ66 ,

    2001 MK3 , 1998 HL1 , 1999 CV8 , 1999 GT3 , 1999 MM , 1999 YA ,

    2000 FL10 , 2000 OK8 , 1999 RL45 , 1999 TN12 , 2001 FA7 , 2001 QP153 ,

    2001 SL9 , 1999 XX262 , 2001 RY11 , 2001 SW169 , 2001 RM ,

    2001 SO73 , 2001 TE2 , 2001 TO103 , 2001 SN289 , 2001 RR17 , 2001 VG5 ,

    2001 UA5 , 2001 XR1 , 2001 XS30 , 2001 VS78 , 2001 MT18 , 2001 XN254 ,

    2001 VG75 , 2001 WG2 , 2001 SN263 , 2001 WC47 , 1999 GL4 , 2002 AG29 ,

    2002 AM31 , 2002 BK25 , 2002 AD9 , 2002 DP3 ,

    Mars-Crossers

    1998 RT4 , 1998 QD2 , 1996 TE11 , 1999 JT3 , 1994 JC , 1998 QP63 ,

    1999 RJ45 , 1999 RC2 , 1999 WY , 1998 VE32 , 1999 CW7 , 1998 XQ16 ,

    1998 AK8 , 1937 UD , 1998 KH17 , 1999 XG135 , 2000 BD1 , 2000 FO3 ,

    2000 GG2 , 2000 HT15 , 1999 XK141 , 2000 OG44 , 2000 JV60 , 1999 RL41 ,

    2000 SO277 , 2000 XR15 , 1988 RO1 , 1999 XS16 ,

    Other Unusual Objects

    1999 RG33 , 1996 TO66 , 1998 WH24 , 2000 ON , 2000 ST317 , 2000 EB173 ,

    2000 WR106 , 2000 WE147 , 2000 SO253 , 2000 WT168 , 1987 Q3 , 2001 KX76 ,


    For questions about this page, please contact Gerhard Hahn

    Updated on April 10, 2002 by Gerhard Hahn