WPLTN Technical Workshop
“One-way and two-way SLR for GNSS co-located with RF techniques”
(WPLTN-2012)

September 24 - 28, 2012
St.Petersburg, Russia.

RESOLUTION
of the International Scientific Technical Conference WPLTN-2012
  1. Considering:
    • * the necessity and importance of increasing the precision of satellite navigation systems worldwide and their integration, which includes matching coordinate systems and time scales to each other;
      * the fact that combining methods of one-way and two-way laser ranging allows the precision of GNSS geodetic and ephemeris time support to be increased substantially, the participants of the International Scientific Technical Conference WPLTN-2012 have come to the common opinion on the following
    :
      1.1 We think laser methods of time transmission to be potentially most accurate both for the purpose of solving a problem of matching time scales with each other in different navigation systems and in order to achieve the goal of transmitting time scales to remote points.
      1.2. We approve the principle of equipping all navigation space crafts both with laser retroreflector systems and receiving devices which register the time a laser pulse is received using the onboard time scale.
      1.3. We recommend deploying laser stations, which are modernized to operate in one-way and two-way laser ranging mode, nearby the national GNSS synchronizers and other holders of central time scale standards.
      1.4. We recommend WPLTN member-countries to give high priority status to observations of GNSS navigation spacecrafts which are equipped with retroreflector systems.
      1.5. We take note that nano-gradient optical coatings have a good future in laser-ranging systems.

  2. Having an opinion that the collocation of various space geodesy measurement technologies has a fundamental role in increasing the accuracy of fundamental and applied positioning, navigation and timing provision, the International Scientific Technical Conference WPLTN-2012 has come to the following conclusions:
      2.1. We find it necessary to expand the laser ranging system network (SLR), as well as other measurement technologies of space geodesy (VLBI, LLR GNSS and DORIS) on national and international sites, giving priority status to those of them which follow the principle of equal geographical distribution and collocation of measurement equipment and which support the proposition to consider installing Russian SLR and GNSS stations on the sites which are situated on WPLTN member-countries’ territories.
      2.2. We approve the concept of creating geodetic spacecrafts equipped with the means of various space geodesy measurement technologies, in particular, the concept of creating a precisely calibrated, multi-functional (for the VLBI, SLR, GNSS and DORIS technologies) specialized spacecraft GRASP, which will provide collocation measurements, and we call on all WPLTN members to take all possible opportunities to participate in its creation (for example, Russia can contribute the “Blits” technology).
      2.3 We acknowledge that the necessary condition for space geodesy development is the creation of new and the modernization of existing laser stations, as well as the methods of their calibration, metrological support and geodetic binding, which would ensure less than one millimeter error for both occasional and systematic cases of measurement.

  3. Considering space debris pollution to be a huge threat to space activities, and acknowledging that this problem requires international cooperation; and noting simultaneously that monitoring methods and active influence on space debris objects are among the perspective trends for activities in this area, the participants of the WPLTN-2012 Conference recommend the following:
      3.1. WPLTN should organize a space debris optical tracking trial campaign using 1 or 2 tracking stations from each member country. Laser tracking is not to be applied to active spacecraft. The main purpose of this campaign is to limit the growth of space debris by reducing the number of collisions between space debris objects and spacecraft by means of generating relevant information allowing such collisions to be avoided.
      3.2. A WPLTN Space collision center [SCC] is to be created in order to explore collision cases and coordinate the Trial campaign.
      3.3. The Trial campaign coordinator Ben Greene (Australia) to send a program and method of observations to all WPLTN members for approval as soon as possible.
      3.4. Laser methods of space debris monitoring are to be applied wherever it is possible in order to increase the precision of flow forecasting.
      3.5. It should be considered that laser based system to manage space debris movement is a technologically possible project, though expensive, would require international cooperation in order to create systems of joint application.

  4. Taking into consideration
      * the fact that the Global Geodetic Observing System GGOS is based on all main measurement technologies of space geodesy (VLBI, SLR, LLR, GNSS and DORIS) and therefore recognized as an important contribution of space geodesy to the global task of researching the Earth as a system;
      * the fact that the main trend of GGOS improvement is the worldwide network development of those stations which collocate various space geodesy measurement technologies, the participants of the International Scientific and Technical Conference WPLTN-2012 should include an item in their agendas to actively use all their facilities to support the IGGOS project.

  5. WPLTN recognizes the special importance of the SALRO station in The Kingdom of Saudi Arabia, and encourages all its members to provide whatever support is possible for SLR and GNSS operations on this site.

© 2012 IAA of RAS