Chinese English

The time interval between the senso­ry perception of a PHENOMENON and the motor reaction thereto. Personal equation may be either positive or negative, as an observer may anticipate the occurrence of an event, or wait until he actually sees it occur before making a record. This is a SYSTE­MATIC ERROR, treated as of the constant type. It is a PERSONAL ERROR, for which the term personal equation is reser­ved. It is of special significance in OBSERVA­TI­ONS of TIME, made to determine CHRONOMETER CORREC­TION.

感知某一现象与对其作出反应之间的时间间隔。个人观测误差有正有负，因为观测者既可能预知事件的发生，又可能在实际看到事件发生后做记录。此误差被视为恒定系统误差。此术语因其为一种人为误差而被保留。它对时间观测格外重要，用于确定精确时计改正。

观测者不能准确感知尺寸值的结果。人差在观测中可能是随机的，也可能是规则的。亦见personal equation（个人观测误差）。

The point of origin or termination of bundles of PERSPEC­TIVE RAYS. The two such points usually associated with a survey photograph are the interior perspective centre and the exterior perspective centre. In a perfect lens-camera system, PERSPECTIVE RAYS from the interior perspective centre to the photographic IMAGES enclose the same angles as the corresponding RAYS from the exterior perspective centre to the objects photographed. In a LENS having DISTORTION this is true only for a particular zone of the PHOTOGRAPH. In a perfectly adjusted lens-camera system the exterior and interior perspective centres correspond, respectively, to the front and rear NODAL POINTS of the camera lens.

透视光束的起点或终点。通常与航摄像片相关，指内透视中心和外透视中心。在完善的透镜拍摄系统中，从内透视中心到像片影像的透视线与相应的从外透视中心到所摄物体的透视线所包含的角相同。在图像失真的透镜中，此情况仅在像片的特殊区域成立。在调好的透镜拍摄系统中，内外透视中心分别与该摄像机镜头的前后节点相对应。

在摄影测量学中，指绘制或加印在像片上的网线，用于表示地面或基准面上系统网线的透视图形。亦见grid method（格网转绘法）。

Any plane containing the PERSPECTI­VE CENTRE. The intersection of a perspective plane and the GROUND will always appear as a straight line on an AERIAL PHOTOGRAPH.

在平面或曲面上，通过可能位于无穷远处的某点发出的投影线，对某种形状进行的再现。亦称geometric projection（几何投影）。

A false BOTTOM indicated by an ECHO SOUNDER, some distance above the actual BOTTOM. Such an indication, quite common in the deeper parts of the OCEAN, is due to large quantities of small organisms. Also called deep scattering layer (DSL) or false bottom.

用回声测深仪测出的在实际海底之上的伪底。这种假象由大量微生物所致，在海洋较深部分普遍存在。亦称deep scattering layer（深海散射层）或false bottom（伪底）。

The visible aspect of an object. The amount by which a CYCLE has progressed from a specified origin. In ASTRONOMY, any of the stages of variation in the illumination of the MOON or a PLANET. See PHASE(S) OF THE MOON. In physics, the state of aggregation of a substance, for example, solid (ICE), liquid (water), or gas (va­pour).

物体的可见部分。 周期内从某特定起点开始所经历的量。 在天文学中，指月亮或行星亮度变化的各个阶段。参见phase of the moon（月相）。 在物理学中，指物质聚集的状态，如固体（冰）、液体（水）或气体（蒸气）。

The phase difference of two periodical­ly recurring PHENOMENA of the same FREQUENCY, expressed in angular measure. The angle at a CELESTIAL BODY between the SUN and EARTH.

Angular retarda­tion of the maximum of a constituent of the observed TIDE behind the correspon­ding maximum of the same con­stituent of the hypotheti­cal EQUILIBRIUM TIDE. Also called tidal epoch.

A visually discrete part of a light signal. It is bounded by changes between darkness and light (e.g. an occultation or flash), or between different colours, or between distinctly different luminous intensities, and it may be further discriminated by its duration.

The various appearances of the MOON during different parts of the SYNODICAL MONTH. The CYCLE begins with new moon or change of the MOON at CONJUNCTION. The visible part of the waxing moon increases in size during the first half of the CYCLE until full moon appears at OPPOSITION, after which the visible part of the waning moon decreases for the remainder of the CYCLE. First quarter occurs when the waxing moon is at east QUADRATURE,last quarter when the waning moon is at west QUADRATURE. From last quarter to new and from new to first quarter the MOON is crescent; from first quarter to full and from full to last quarter it is gibbous.

在朔望月不同阶段中月亮的各种外观。月相周期从新月或合时月亮的改变开始。在其前半周，盈月亮面逐渐增大，直至满月出现在太阳冲位，在其后的后半周，亏月亮面逐渐变小。上弦月发生在盈月位于东方照时，下弦月发生在亏月位于西方照时。从下弦到朔再到上弦时的月亮为蛾眉月；从上弦到望再到下弦时的月亮为凸月。