heliogram是什么意思

n.反光信号

1. The heliogram was used as a method of long-distance communication in the past.
过去，太阳信号被用作远距离通信的一种方法。
2. The heliogram depicted the shape of the sun in great detail.
太阳图详细描绘了太阳的形状。

太阳信号；太阳电报；太阳图