With the rapid development of new-generation information and communication technologies, such as artificial intelligence, big data, digital twins, and AR/VR, maps has exhibited a significant trend toward diversification, giving rise to a large number of pan-map forms that are distinct from traditional maps. The representational space of pan-maps has expanded from the “physical-social cultural” dual space to a ternary space encompassing the physical, social cultural, and information domains. To address the challenge that traditional two-dimensional static map symbol systems are inadequate for the multi-dimensional, multi-modal, and multi-scenario expressive needs of pan-maps in the ternary space, this study draws upon cartographic linguistics and the theory of visualization dimensions for pan-maps to construct a pan-map symbol system oriented toward objects in ternary space, and systematically elucidates its underlying expressive mechanisms. By integrating Saussure's dyadic semiotics and Peirce's triadic semiotics, we first clarify the essence of pan-map symbols as carriers of meaning construction and information transmission. We then extend the connotations of image, graphic, and textual symbols, revealing the continuous transition of pan-map symbols from precise geometry to realistic (concrete) and freehand (abstract) expression, and construct a continuous spectrum in which image symbols shift from “two-dimensional images” to “three-dimensional realistic representations”, while graphic symbols transition from “geographic geometry” to “conceptualized expression”. Finally, we systematically analyze the operational logic of the semantic, syntactic, and pragmatic dimensions of pan-map symbols. At the semantic level, they exhibit a tripartite signifying relationship of iconicity, indexicality, and symbolism, along with rhetorical heuristicness. At the syntactic level, visualization dimensions serve as the underlying grammatical units, establishing a hierarchical reconstruction rule of “basic morpheme—symbol word—symbol sentence” and distilling visual rhetorical rules encompassing visual enhancement, semantic transformation, and spatiotemporal narration. At the pragmatic level, we summarize four core modes—geometric convention, scene realism, cognitive reinforcement, and intertextual metaphor—that drive the spatial meaning construction of symbols across diverse scenarios. This study reveals the visualization logic of pan-maps in the information age and is expected to provide theoretical support for the expansion of the theoretical framework of pan-cartography.
