通过撞击特定纬度带的概率与该纬度带内的人口（在轨道倾角覆盖的纬度范围内进行积分）的乘积获得Ec的公式

[中文适用范围]： 本文件提供了一个框架，用于评估、降低和控制航天器和运载火箭轨道级（以下简称“航天器”）在重返地球大气层并撞击地球表面时对人类和环境造成的潜在风险。本文件旨在应用于不可避免地需要受控或不受控重返大气层的航天器任务的规划、设计和审查。本文件适用于评估以下物体对地面的风险：a) 符合 ISO 24113 的从轨道重返大气层的物体；b) ISO 14620-2[1] 飞行安全活动中提到的运载火箭（包括有效载荷、上升阶段分离的其他物体等）；c) 返回地球的行星际航天器。本文件是对 ISO 14620-1 和 ISO 17666 的补充。本文件不适用于装有核动力源的航天器[2]。注 1 本文件不适用于带有用于目标着陆的机翼和控制功能的航天运输系统。注 2 本文件的有用背景信息可在 ISO 24113 中找到。 [外文原描述]： This document provides a framework with which to assess, reduce, and control the potential risks that spacecraft and launch vehicle orbital stages (referred to hereinafter as "space vehicles") pose to people and the environment when those space vehicles re-enter the Earth's atmosphere and impact the Earth's surface. It is intended to be applied to the planning, design, and review of space vehicle missions for which controlled or uncontrolled re-entry is inevitable. This document is applicable to following objects in assessing their risk to the ground: a) objects re-entering from orbit in conformance with ISO 24113; b) launch vehicles (including payloads, other objects separated during the ascent phase, etc.) that are mentioned in flight safety activities under ISO 14620‑2[1]; and c) interplanetary spacecraft returning to Earth. This document complements ISO 14620‑1 and ISO 17666. This document is not applicable to spacecraft containing nuclear power sources[2]. NOTE 1 This document does not apply to Space Transportation Systems with wings and control functions intended for targeted landing. NOTE 2 Useful background information for this document is available in ISO 24113.