For a system, a priori identifiability is a theoretical property depending only on the model and guarantees that its parameters can be uniquely determined from observations. This paper provides a survey of the various and numerous definitions of a priori identifiability given in the literature, for both deterministic continuous and discrete-time models. A classification is done by distinguishing analytical and algebraic definitions as well as local and global ones. Moreover, this paper provides an overview on the distinct methods to test the parameter identifiability. They are classified into the so-called output equality approaches, local state isomorphism approaches and differential algebra approaches. A few examples are detailed to illustrate the methods and complete this survey.

对于系统，先验可识别性是仅取决于模型的理论属性，并保证可以从观察中唯一确定其参数。本文针对确定性连续时间模型和离散时间模型，对文献中给出的先验可识别性的各种定义进行了调查。通过区分分析和代数定义以及局部和全局定义进行分类。此外，本文概述了测试参数可识别性的各种方法。它们被分为所谓的输出相等法，局部状态同构法和微分代数法。详细说明了一些示例，以说明方法并完成此调查。