Korea’s lunar exploration project includes the launching of an orbiter, a lander (including a rover), and an experimental orbiter (referred to as a lunar pathfinder). Laser altimeters have played an important scientific role in lunar, planetary, and asteroid exploration missions since their first use in 1971 onboard the Apollo 15 mission to the Moon. In this study, a laser altimeter was proposed as a scientific instrument for the Korean lunar orbiter, which will be launched by 2020, to study the global topography of the surface of the Moon and its gravitational field and to support other payloads such as a terrain mapping camera or spectral imager. This study presents the baseline design and performance model for the proposed laser altimeter. Additionally, the study discusses the expected performance based on numerical simulation results. The simulation results indicate that the design of system parameters satisfies performance requirements with respect to detection probability and range error even under unfavorable conditions.

1. INTRODUCTION
 2. BASELINE DESIGN OF LALE INSTRUMENT
 3. PERFORMANCE MODEL
  3.1 Signal and Noise
  3.2 APD Output Statistics
  3.3 Probabilities of Detection and False Alarm
  3.4 Signal-to-Noise Ratio and Range Error
  3.5 Echo Pulse Width
 4. SIMULATION RESULTS AND DISCUSSION
 5. CONCLUSIONS
 REFERENCES

• Hyung-Chul Lim(Korea Astronomy and Space Science Institute, Daejeon 34055, Korea) Corresponding Author
• Gregory A. Neumann(NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA)
• Myeong-Hwan Choi(Korea Astronomy and Space Science Institute, Daejeon 34055, Korea)
• Sung-Yeol Yu(Korea Astronomy and Space Science Institute, Daejeon 34055, Korea)
• Seong-Cheol Bang(Korea Astronomy and Space Science Institute, Daejeon 34055, Korea)
• Neung-Hyun Ka(Korea Astronomy and Space Science Institute, Daejeon 34055, Korea)
• Jong-Uk Park(Korea Astronomy and Space Science Institute, Daejeon 34055, Korea)
• Man-Soo Choi(Korea Astronomy and Space Science Institute, Daejeon 34055, Korea)
• Eunseo Park(Korea Astronomy and Space Science Institute, Daejeon 34055, Korea)