Delta-DOR（Delta-Differential One-Way Ranging）是一种甚长基线干涉测量（VLBI）技术，可与多普勒和测距数据结合使用，通过更有效地确定航天器在天空平面上的角度位置来改善航天器导航。它涉及使用可能属于不同机构的多个地面站同时采集航天器或类星体信号（见参考文献[D2]）。 本Delta DOR原始数据交换格式（RDEF）推荐标准规定了在空间机构之间交换Delta DOR原始数据时使用的标准格式。每次数据关联涉及至少一个不属于负责关联的机构的参与站时，都需要进行Delta DOR原始数据交换。ISO 20208:2015包括数据格式设计满足的参数字段规范。 对于这些规范不能满足参与机构需求的交易所，可以选择另一种机制。

Delta-DOR (Delta Differential One-Way Ranging) is a Very Long Baseline Interferometry (VLBI) technique that can be used in conjunction with Doppler and ranging data to improve spacecraft navigation by more efficiently determining spacecraft angular position in the plane of sky. It involves the use of multiple ground stations, possibly belonging to different agencies, for simultaneous acquisition of either spacecraft or quasar signals (see reference [D2]). This Delta-DOR Raw Data Exchange Format (RDEF) Recommended Standard specifies a standard format for use in exchanging Delta-DOR raw data among space agencies. Delta-DOR raw data exchange is required every time the data correlation involves at least one participating station not belonging to the agency responsible for the correlation. ISO 20208:2015 includes specifications on the parameter fields that the data format has been designed to meet. For exchanges where these specifications do not capture the needs of the participating agencies another mechanism may be selected.