In the process of sunshine map interpretation, whether the partial map is converted to the overall map or the combined map is converted to the common map, the following two aspects should be paid attention to during the conversion:

1.绘制转换新图时，一定要明确图上点、线、面的空间关系。归纳起来主要有：

1. When drawing a new transformation diagram, be sure to clarify the spatial relationship of points, lines and surfaces on the diagram. To sum up, it mainly includes:

(1)地轴、直射点的太阳光线一定通过地球球心。

(1) The sun's rays at the earth's axis and direct point must pass through the earth's center.

(2)太阳光线所示的平面为黄道平面，黄道平面与赤道平面成23°26′的夹角。

(2) The plane shown by the sunlight is the ecliptic plane, which forms an included angle of 23 ° 26 'with the equatorial plane.

(3)各纬线圈与赤道平行、与各经线相互垂直。

(3) Each weft coil is parallel to the equator and perpendicular to each longitude.

(4)各经线都相交于南北两极点。

(4) Each meridian intersects the north and south poles.

(5)晨昏线与各纬线既可垂直，也可斜交;与极圈内的各纬线还可相切、相离(极圈上出现极昼或极夜);平分赤道(即赤道与晨昏线的两交点经度相差180°，即赤道昼夜平分);与各经线既可斜交，也可重合。

(5) The morning twilight line can be perpendicular or oblique to each weft line; It can also be tangent and separated from the weft lines in the polar circle (polar day or night appear on the polar circle); Bisector the equator (i.e. the longitude difference between the two intersections of the equator and the morning dusk line is 180 °, i.e. the equator bisects day and night); It can skew or coincide with each meridian.

(6)晨昏线把相交的各纬线圈分为昼弧和夜弧，根据昼弧和夜弧的长度(所跨经度)可确定该纬线的昼夜长短;如果与各纬线垂直，则晨昏线必定通过南北两个极点，且该日全球昼夜平分。

(6) The morning twilight line divides the intersecting weft coils into day arc and night arc, and the day and night length of the weft can be determined according to the length (longitude) of day arc and night arc; If it is perpendicular to each latitude line, the morning twilight line must pass through the north and south poles, and the global day and night equinox on that day.

2.把握好时间点的转换。转换时的注意事项主要有：

2. Grasp the conversion of time points. Precautions during conversion mainly include:

(1)赤道上昼夜始终平分，晨昏线与赤道的交点位置可以通过时间计算(6时、18时)或通过经度判读在新图中找到。

(1) Day and night are always equinox on the equator. The intersection position of the morning twilight line and the equator can be found in the new map through time calculation (6:00, 18:00) or longitude interpretation.

(2)晨昏线与纬线圈切点位置的确定，可以通过切点时间(12时、0时或24时)推算出经度，再通过直射点位置确定其纬度。

(2) For the determination of the tangent position of the morning twilight line and the latitude coil, the longitude can be calculated through the tangent time (12:00, 0:00 or 24:00), and then the latitude can be determined through the direct point position.

(3)晨昏线与赤道的交点、与纬线圈切点位置确定后，就可用平滑曲线连接起来，但要注意太阳光线与晨昏线始终垂直。

(3) After the intersection of the morning twilight line and the equator and the tangent point of the latitude coil are determined, it can be connected with a smooth curve, but it should be noted that the sun light is always perpendicular to the morning twilight line.

(4)太阳直射点永远位于南北回归线之间，晨昏线与纬线圈相切的点永远位于极圈上及其以内。

(4) The direct point of the sun is always between the Tropic of cancer, and the point tangent to the weft coil is always on and within the polar circle.