# Remote Sensing for Land Administration
## 1 Introduction  
Land administration is the process of recording, securing, and disseminating information about land tenure, value, use, and development, within a jurisdiction [1]. As a study area, soft systems methodology, socio-technical systems, and geo-information science provide contemporary theoretical foundations [2]. Conventionally, the primary unit of concern is the land parcel-a multi-dimensional spatial extent, with associated rights, and a party who is said to hold those rights [3]. In practice, land administration aggregates all the land parcel information into a system, enabled through the mandate of prescribed administrative roles, processes, and supportive technologies [4]. The functioningsystem enables land dispute resolution, transaction controls, credit access, land transfer, land valuation, land taxation, changes in land use, and development decisions [5]. Modern land administration systems utilize information technology: existing paper records are digitized, manual recording and dissemination processes digitalized, with all aspects being constituted into a publicly accessible land information system [6]. In more developed contexts, land administration systems have generally developed, over the centuries, from narrowly purposed land registries and cadastres, into whole-of-jurisdiction multi-purpose systems, to support the contemporary policy objectives of good governance and sustainable development [7; 8]. In developing contexts, much effort is afforded in establishing or renewing systems. Challenges stemming from anachronous colonial-era systems; limited techniques for recording customary forms of tenure; the lack land rights records of women; the want of legal documentation for the legitmate rights of the poor and vulnerable; and scarce technical skills and capacity--all conspire to impede responsible land administration development [9; 10; 11]. Meanwhile, all systems, regardless of the country context, are challenged by the emergent demands of rapid urbanization, climate-change response, digital transformation (and e-services), gender equality, and demands for openness and transparency [12; 13]. In practical terms, this results in research, development and implementations relating to 3D (and 4D) cadastres [14; 15], domain standardization and interoperability [3; 16; 17] (e.g., ISO 19152 Land Administration Domain Model LADM and ISO TC211), land rights fractionalization and new database structures [18] (e.g., big data analytics, NoSQL, and blockchain), fit-for-purpose land administration [19], and novel land data collection approaches [20; 21; 22]. The abovementioned developments confirm spatial information is a central concern of land administration systems. Spatial information delineates the boundaries between lands parcels. These boundaries can be 'general' or 'fixed' in nature [1]. To be recognized, the boundaries require 'perception' of existence by a community; an explicitly defined 'purpose'; an actual or physical field 'presence', a defined 'period-in-time' of application, and a 'presentation' or documented representation (which may be digital) [23]. More recently, clarification of the interrelationship between the physical, documented, and digital aspects is provided [24; 25]. Conventionally, ground-based survey methods, often underpinned by local or national geodetic networks, support making observations, demarcating boundaries, and surveying boundary information. This in turn enables the derivation of boundary coordinates [24]. These coordinates enable a parcel to be recorded and represented on survey sketches, cadastral plans, cadastral maps, and in the contemporary era, cadastral databases. Over time, surveying tools and techniques have improved: rudimentary rope surveys, plane table usage, theodolite application, and electronic distance measurement (EDM), have given way to total stations and high-precision global navigation satellite systems (GNSS) (Note: whilst the survey and receiver are ground-based, the space segment (i.e. GNSS satellites) are not) [1; 8].