Table 1 Typology of active and passive sensing combinations informing urban transformation, featuring benefits and risks of the combinations for stakeholders.

Uncoupled passive and active sensing

Applies both passive and active sensing without interactions

Case 1: Zurich, Switzerland

Elements of the sensing systems: Geospatial statistical data, surveys, planning workshops, database of passive sensing data. Spheres of transformation: The uncoupled passive and active sensing processes did not allow an objectively informed land use planning. While the active sensing process enabled social learning among citizens, planners and authorities (personal sphere) and empowered the local community to engage in the political process and local activities (political sphere), it only weakly built on available knowledge. The resulting implementation of the legal binding plan (practical sphere) required afterwards several intensive pilot processes, as stakeholders did not agree on the concrete implementation measures in space.

General: Fast to set up and obtain results. Passive sensing alone can support fast elicitation processes, while active sensing alone can support public engagement. Spheres of transformation: Active sensing alone can foster learning among individuals (personal sphere) and strengthen social capital of wider societal groups (political sphere), resulting in community actions (practical sphere). Passive sensing alone can provide background knowledge for transformation in the various spheres, in particular for planners in the practical sphere and regulating bodies of the political sphere.

General: Difficult to anticipate how well or where outputs intersect to inform the solution space of transformation; difficult to separate causalities from confounding factors; potential issues of procedural and recognition justice; disregard of compatibility of active and sensing data e.g. different time scales of data collection; geographic scale mismatches; issues of representation of diverse knowledge systems. Spheres of transformation: Weak political moderation inhibits changes in planning interventions (practical sphere). Changes in individual worldviews, values and beliefs (personal sphere), and legal systems (political sphere) developed by governing bodies cannot be clearly linked to planners’ interventions (practical sphere). Risk of misuse of knowledge and misguided transformation in the practical sphere.

Dominant role of passive sensing

Integrates both sensing types with a focus on passive sensing systems.

Case 2: Singapore

Elements of the sensing systems: Geospatial statistical data, Earth Observation data and social media data, co-design and planning workshops. Spheres of transformation: The strong passive sensing component created a knowledge base about Singapore’s natural capital. The integration of this knowledge into a participatory 3D virtual platform actively engaged various agencies (political sphere), but the agencies did not want to directly use the open source software and the related ecosystem services data (practical sphere). Passive sensed data were communicated through several news channels, highlighting Singapore’s natural capital and strengthening the agencies to continue to include it into their decision-making (personal sphere).

General: Effective at describing actual situation; ample data; reproducible and transparent; useful for long-term assessments. Spheres of transformation: High potential for generating a knowledge basis for planners, businesses and facility managers to define urban plans and management strategies (practical sphere); high-quality passively sensed data from a trusted source can trigger awareness for sustainability challenges by regulating bodies in the political and even individuals in the personal spheres.

General: Datasets often incomplete, especially personal information (e.g. age, gender, education); poor utilization of passive datasets, as active sensing is weak in defining passive sensing (e.g. data access, temporal and spatial scales, data units). Spheres of transformation: Weak governing bodies in the political sphere impedes the delineation of conditions necessary for practical transformation and for defining priorities in actions. Major ethical challenges in individual data ownership and sharing (personal sphere). Neglect of solution space concerning individual and groups behavioural motivations and preferences (personal sphere).

Dominant role of active sensing

Integrates both sensing types with a focus on active sensing systems.

Case 3: Dar Es Salaam, Tanzania

Elements of the sensing systems: Earth Observation data, participatory mapping and modelling, citizen observation, co-design and planning workshops. Spheres of transformation: Integrating passive and active sensing has enabled creation of up-to-date spatial information of the city and thus substantially narrowed the previously existing data gap (practical sphere). Spatial up-to-date information has informed land use planning and action-oriented decisions of the government, international investors and global organizations (political sphere) and in the local communities (personal sphere).

General: Allows geospatial data production through local data collection and validation; creates community ownership to data; data production process is based on open source software and open access licensing of the datasets. Spheres of transformation: Facilitates planning, investment by government, investors and global organizations, and community actions based on digital data (practical and political spheres); creates substantially improved individual and local community ownership and capacities to react to flood risks on the basis of local knowledge (personal and practical spheres).

General: Production of digital urban planning data is challenging when rapid urban growth takes place and digital planning data production and utilization is not yet institutionalized. Spheres of transformation: Since the data production is integrating passive and active sensing, data utilization and updating by planners and businesses (practical sphere) is dependent on political commitment and institutionalization of data production (political sphere); detailed level open access data of the city (e.g. drone images) may also offer opportunities for misuse by governing bodies (political sphere); maintaining active sensing is critical for successful data production and utilization process at all action levels (practical, political and personal spheres).

Balanced sensing

Includes balanced used of passive and active sensing with weak interactions.

Case 4: LAHTI, Finland

Elements of the sensing systems: Geospatial statistical data, participatory mapping, co-design and planning workshops, joint database for active and passive sensing Spheres of transformation: Using passive and active sensing in a balanced way provides concrete planning support system for informing the transformation, especially in the practical sphere and also in personal and political spheres. The database combining active and passive sensing information supported the diagnosis and explanation actions in the sustainability transformation (practical and political spheres).

General: Supports understanding of reciprocal human-environment interactions (personal sphere); harnessing both active and passive sensing data across different sectors helps overcome the difficult trade-offs during the transformation processes. Spheres of transformation: Rapid and incremental transformation in the practical sphere, driven by planners and businesses; increased individual stewardship for transformation process (personal sphere); agile transformation of the political sphere, carried out by regulating bodies.

General: Established dialogical decision-making culture is needed; difficult to assess the direction and intensity of the transformation due to incremental changes (practical and political spheres); challenging to harness leverage points across the spheres, in particular personal sphere. Spheres of transformation: The amount of active sensing data can become excessive and choosing between the most usable datasets and possible expiry dates remain challenging for planners and businesses (practical sphere); exhaustion of participants can become a challenge (personal sphere) and offer opportunities for political misuse (political sphere).