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?????????????????CEGM02????????LRO_LTM02??????????????α?????????????ο??????棬??????????????棬??????λ??W0??=2 822 327.8±16.2 m² s^-2??????????????????????????????????1 737 462 m??????????1/2 579?????????1/6 863??????????-76.8 ″??????ο???????òο??????????????????????????????????????С?60×10^-5ms^-2??????????????25×10^-5ms^-2?????????????-325.9 ??389.1 m??

A NEW SELENOID MODEL AND REFERENCE TRIAXIAL LEVEL ELLIPSOID

??A new selenoid (lunar geoid) is derived using the lunar gravity model CEGM02 and topography model LRO_LTM02, which approximates the physical surface as closely as possible. The estimated gravity potential value of this selenoid is 2 822 327.8±16.2 m??²/s??², denoted as ??W??0?? in usual. A triaxial level ellipsoid whose surface gravity potential equals ??W₀?? above is calculated and used as a reference ellipsoid, and its semi??major axis, polar flattening, equator flattening and longitude of semi??major axis are 1 737 462 m, 1/2 579, 1/6 863 and -76.8 ″, respectively. Based on this reference ellipsoid, the gravity decreases about 60×10^-5ms^-2 from the equator to the poles, while the variation along the equator is about 25×10^-5ms^-2. The selenoid undulations are in the range of -325.9 m to 389.1 m.