Skip to main content

Geodesy in the Year 2000 (1990) / Chapter Skim
Currently Skimming:

Lasers for Geodesy in the Year 2000
Pages 91-99

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.


From page 91...
... In 1983 NASA organized a meeting called the Airlie House Conference (Walter, 1984) to discuss the scientific requirements for future space geodetic systems, including laser ranging.
Read the entire page →
From page 92...
... At the present time flashlamps used in laser ranging systems have effective lifetimes on the order of 106 shots -- months of actual operation or days of continuous operation, while the potential for diode pumping is on the order-of 109 shots -- decades of actual operation or years of continuous operation. This development of long lifetime lasers makes spaceborne systems viable.
Read the entire page →
From page 93...
... This may cause pulse rates to increase from their present 5 to 10 pulses per second to the order of 1000 pulses per second, and for return pulses to be averaged to produce an accurate measurement. The design of the laser array and precise knowledge of the array's position with respect to the center of mass of the spacecraft could become a limiting factor in the development of increasingly accurate laser ranging systems.
Read the entire page →
From page 94...
... In the mapping mode, the system would obtain 300 meter spots that would be interpolated to provide a 1-2 kilometer global lunar topographic grid appropriate for geodetic and geophysical studies and regional characterization of all major terrain types. In the high resolution mode, LOLA would obtain 30 meter spots to be used for localscale geological profiling.
Read the entire page →
From page 95...
... from the EOS platform or a similar system; and (3) laser altimetry providing topographic information of the Earth and Moon, and possibly the planets, at the 30 cm vertical precision level with decameter horizontal resolution.
Read the entire page →
From page 96...
... L Bufton, Lunar Observer Laser Altimeter: Geoscience Applications, Lunar Planet.
Read the entire page →
From page 97...
... 97 Table 1: The Laser Transmitter 1987 1 color flash lamp pumping flash lamp efficiency 1% - 2% laser lifetimes: 106 shots pulse length: 100 x 10-~2 sees Table 2: Accuracy (best systems) Pulse rate Laser Energy Pulse length Data communication Automation 2000 2 colors diode pumping Ground-Based Laser System 1987 1 cm (excl.
Read the entire page →
From page 98...
... 0.1 milliradians 40 pps 18 cm Table 4: Characteristics of the EOS and lunar laser altimeters EOS Orbital altitude Frequency Pulsewidth Energy/pulse Receiver telescope diameter Spot size Lunar 800 km 1064 rim 100 ps 120 mj 50 cm 80, 160 m 100 km 1064 rim 3 us 2 mj 25 cm 30, 300 m Vertical precision 10- 50 cm 30 cm (excl. atmosph .
Read the entire page →
From page 99...
... Spaceborne laser ranging and altimetry concept.
Read the entire page →

Key Terms

  • spaceborne laser
  • laser altimeter
  • diode pumping
  • pulse lengths
  • horizontal resolution

  • eos spaceborne
  • laser altimetry
  • lunar observer
  • satellite laser
  • provide decimeter

  • lunar laser
  • horizontal resolutions
  • range measurements
  • lunar planet
  • flight center

  • short pulse
  • laser ranger
  • continuous operation
  • actual operation
  • observer laser

  • geodetic tool
  • nasa goddard
  • ieee trans
  • space flight
  • increased accuracy

  • pulse rates
  • goddard space
  • vertical precision
  • scientific requirements
  • laser array


    • This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
    More information on Chapter Skim is available.