Web Mapping Market Outlook

The global web mapping market size was valued at approximately USD 3.5 billion in 2023 and is projected to reach USD 8.2 billion by 2032, growing at a compound annual growth rate (CAGR) of 9.8% during the forecast period. The robust growth of this market can be attributed to the increasing demand for geographic information system (GIS) technologies and the expanding applications of web mapping across various industries.

One of the primary growth factors driving the web mapping market is the proliferation of location-based services. With the rise of smartphones and IoT devices, the demand for real-time location data has skyrocketed, fueling the need for advanced web mapping solutions. Businesses are leveraging location-based services to enhance customer engagement, optimize logistics, and improve decision-making processes. Moreover, the integration of web mapping with emerging technologies such as AI and machine learning is further bolstering market growth, allowing for more sophisticated and predictive mapping capabilities.

Another critical factor contributing to the market's expansion is the growing adoption of web mapping solutions in government and public sector initiatives. Governments across the globe are increasingly utilizing web mapping technologies for urban planning, disaster management, and community services. These technologies provide invaluable insights and real-time data that aid in making informed decisions and improving public services. The push for smart city developments and the need for efficient infrastructure management are also significant drivers for the adoption of web mapping solutions in the public sector.

Furthermore, the transportation and logistics industry is witnessing a substantial uptake of web mapping technologies. With the rise of e-commerce and the need for efficient supply chain management, companies are relying on web mapping to optimize routes, monitor shipments, and ensure timely deliveries. The integration of GPS technology and real-time tracking systems with web mapping solutions is enhancing operational efficiencies and reducing costs. This trend is likely to continue as the demand for seamless logistics and transportation services grows.

The concept of an Electronic Map has become increasingly significant in the web mapping market. Electronic maps are digital representations of geographic areas and are pivotal in providing real-time data and location-based insights. They are extensively used in various applications, from navigation systems to urban planning and environmental monitoring. The integration of electronic maps with web mapping technologies allows for enhanced visualization and analysis of spatial data, offering users detailed and interactive geographic information. As the demand for digital mapping solutions continues to grow, electronic maps are playing a crucial role in transforming how geographic information is accessed and utilized across different sectors.

On the regional front, North America remains a dominant player in the web mapping market, primarily due to the early adoption of advanced technologies and the presence of major market players in the region. The Asia Pacific region is expected to exhibit the highest growth rate during the forecast period, driven by rapid urbanization, technological advancements, and increasing investments in smart city projects. Europe and Latin America are also anticipated to witness significant growth, supported by favorable government initiatives and the expanding use of web mapping across various industries.

Component Analysis

The web mapping market can be segmented by component into software and services. The software segment encompasses a wide range of GIS and mapping software that enable users to create, visualize, and analyze geographic data. This segment is witnessing significant growth due to the increasing need for sophisticated mapping tools that offer real-time data and advanced analytical capabilities. Companies are continuously enhancing their software offerings with features like AI integration, cloud compatibility, and user-friendly interfaces, driving the adoption of web mapping software across various industries.

On the other hand, the services segment includes a variety of professional services such as consulting, implementation, and maintenance. As organizations seek to leverage web mapping technologies, they often require expert guidance and support to ensu

The digital map market, currently valued at $25.55 billion in 2025, is experiencing robust growth, projected to expand at a compound annual growth rate (CAGR) of 13.39% from 2025 to 2033. This expansion is fueled by several key factors. The increasing adoption of location-based services (LBS) across various sectors, including transportation, logistics, and e-commerce, is a primary driver. Furthermore, the proliferation of smartphones and connected devices, coupled with advancements in GPS technology and mapping software, continues to fuel market growth. The rising demand for high-resolution, real-time mapping data for autonomous vehicles and smart city initiatives also significantly contributes to market expansion. Competition among established players like Google, TomTom, and ESRI, alongside emerging innovative companies, is fostering continuous improvement in map accuracy, functionality, and data accessibility. This competitive landscape drives innovation and lowers costs, making digital maps increasingly accessible to a broader range of users and applications. However, market growth is not without its challenges. Data security and privacy concerns surrounding the collection and use of location data represent a significant restraint. Ensuring data accuracy and maintaining up-to-date map information in rapidly changing environments also pose operational hurdles. Regulatory compliance with differing data privacy laws across various jurisdictions adds another layer of complexity. Despite these challenges, the long-term outlook for the digital map market remains positive, driven by the relentless integration of location intelligence into nearly every facet of modern life, from personal navigation to complex enterprise logistics solutions. The market's segmentation (although not explicitly provided) likely includes various map types (e.g., road maps, satellite imagery, 3D maps), pricing models (subscriptions, one-time purchases), and industry verticals served. This diversified market structure further underscores its resilience and potential for sustained growth. Recent developments include: December 2022 - The Linux Foundation has partnered with some of the biggest technology companies in the world to build interoperable and open map data in what is an apparent move t. The Overture Maps Foundation, as the new effort is called, is officially hosted by the Linux Foundation. The ultimate aim of the Overture Maps Foundation is to power new map products through openly available datasets that can be used and reused across applications and businesses, with each member throwing their data and resources into the mix., July 27, 2022 - Google declared the launch of its Street View experience in India in collaboration with Genesys International, an advanced mapping solutions company, and Tech Mahindra, a provider of digital transformation, consulting, and business re-engineering solutions and services. Google, Tech Mahindra, and Genesys International also plan to extend this to more than around 50 cities by the end of the year 2022.. Key drivers for this market are: Growth in Application for Advanced Navigation System in Automotive Industry, Surge in Demand for Geographic Information System (GIS); Increased Adoption of Connected Devices and Internet. Potential restraints include: Growth in Application for Advanced Navigation System in Automotive Industry, Surge in Demand for Geographic Information System (GIS); Increased Adoption of Connected Devices and Internet. Notable trends are: Surge in Demand for GIS and GNSS to Influence the Adoption of Digital Map Technology.

GPS Development Tool Market Outlook

The global GPS development tool market size is projected to expand from $XX billion in 2023 to $XX billion by 2032, growing at a CAGR of XX%. This growth is driven primarily by increasing demand for precision navigation systems across various sectors. The integration of GPS technology in everyday applications and the burgeoning dependency on location-based services have significantly contributed to the expansion of the GPS development tool market.

One of the key growth factors in the GPS development tool market is the widespread adoption of GPS technologies in the automotive industry. As autonomous vehicles and advanced driver-assistance systems (ADAS) gain traction, the need for precise and reliable navigation systems has surged. These systems rely heavily on GPS development tools for accurate positioning and navigation, ensuring safety and efficiency in transportation. Furthermore, the increasing focus on reducing traffic congestion and enhancing fleet management capabilities has augmented the demand for GPS-enabled solutions.

Another critical driver for market growth is the expanding application of GPS technologies in the agriculture sector. Precision agriculture, which utilizes GPS tools for activities such as field mapping, soil sampling, and crop monitoring, has revolutionized farming practices. By enabling farmers to optimize resource usage and improve crop yields, GPS development tools have become indispensable in modern agriculture. The ongoing advancements in GPS technology, such as real-time kinematic (RTK) and differential GPS (DGPS), have further propelled their adoption in this sector.

The aerospace and defense sectors also play a pivotal role in driving the GPS development tool market. Military operations, surveillance, and reconnaissance missions heavily depend on GPS for accurate navigation and timing. The growing investments in defense modernization programs and the rising demand for unmanned aerial vehicles (UAVs) have fueled the need for advanced GPS tools. Additionally, the increasing emphasis on enhancing national security and border control measures has further amplified the demand for robust GPS systems in these sectors.

Regionally, North America holds a significant share in the GPS development tool market, driven by technological advancements and early adoption of GPS technologies. The presence of major market players and a well-established infrastructure for research and development contribute to the region's dominance. Moreover, the increasing demand for smart transportation solutions and the rising adoption of GPS-enabled applications in industries such as automotive and agriculture further bolster the market growth in North America.

Product Type Analysis

In the GPS development tool market, the product type segment encompasses hardware, software, and services. Each sub-segment holds distinct importance and caters to diverse needs across various industries. The hardware segment includes GPS modules, receivers, antennas, and other related components essential for the functioning of GPS systems. These hardware components are integral to capturing and processing satellite signals, ensuring accurate positioning and navigation. The continuous advancements in hardware technologies have led to the development of more compact, efficient, and reliable GPS devices, thus boosting their adoption across different applications.

The software segment within the GPS development tool market comprises various applications and platforms that facilitate the analysis, visualization, and interpretation of GPS data. This includes mapping software, geographic information systems (GIS), and other specialized applications designed for specific industries. The increasing demand for real-time data analysis and the growing emphasis on enhancing user experience have significantly driven the growth of the software segment. Additionally, the integration of artificial intelligence (AI) and machine learning (ML) algorithms in GPS software solutions has enabled more accurate predictions and insights, further propelling their adoption.

Services constitute another crucial component of the GPS development tool market. This segment includes consulting, implementation, maintenance, and support services provided by various vendors. As organizations increasingly rely on GPS technologies for their operations, the need for expert guidance and support has become paramount. Service providers play a vital role in ensuring the seamless integration and efficient functioning of GPS systems. Moreover, the g

Services: This segment encompasses consulting, map development and customization, and data collection and processing services.Solutions: Includes ready-to-use mapping solutions for specific industries and applications, such as fleet management, navigation, and disaster response.Functionality: Categorized based on map capabilities, including scientific mapping for research and analysis, GPS navigation for vehicle navigation, and computerized mapping for computer-aided design.Application: Segmented by indoor and outdoor mapping, catering to different use cases and requirements.Technology: Includes Geographic Information Systems (GIS), Digital Orthophotography (DOP), Aerial Photography, and others, each offering unique capabilities for map creation and analysis. Recent developments include: July 2022: Google declared the launch of its Street View experience in India in collaboration with Genesys International, an advanced mapping solutions company, and Tech Mahindra, a provider of digital transformation, consulting, and business re-engineering solutions and services. Google, Tech Mahindra, and Genesys International also plan to extend this to more than around 50 cities by the end of the year 2022.. Potential restraints include: Lack of Skilled Expertise, High Deployment Cost.

GIS Data Collector Market Outlook

The global GIS Data Collector market size is anticipated to grow from USD 4.5 billion in 2023 to approximately USD 12.3 billion by 2032, at a compound annual growth rate (CAGR) of 11.6%. The growth of this market is largely driven by the increasing adoption of GIS technology across various industries, advances in technology, and the need for effective spatial data management.

An important factor contributing to the growth of the GIS Data Collector market is the rising demand for geospatial information across different sectors such as agriculture, construction, and transportation. The integration of advanced technologies like IoT and AI with GIS systems enables the collection and analysis of real-time data, which is crucial for effective decision-making. The increasing awareness about the benefits of GIS technology and the growing need for efficient land management are also fuelling market growth.

The government sector plays a significant role in the expansion of the GIS Data Collector market. Governments worldwide are investing heavily in GIS technology for urban planning, disaster management, and environmental monitoring. These investments are driven by the need for accurate and timely spatial data to address critical issues such as climate change, urbanization, and resource management. Moreover, regulatory policies mandating the use of GIS technology for infrastructure development and environmental conservation are further propelling market growth.

Another major growth factor in the GIS Data Collector market is the continuous technological advancements in GIS software and hardware. The development of user-friendly and cost-effective GIS solutions has made it easier for organizations to adopt and integrate GIS technology into their operations. Additionally, the proliferation of mobile GIS applications has enabled field data collection in remote areas, thus expanding the scope of GIS technology. The advent of cloud computing has further revolutionized the GIS market by offering scalable and flexible solutions for spatial data management.

Regionally, North America holds the largest share of the GIS Data Collector market, driven by the presence of key market players, advanced technological infrastructure, and high adoption rates of GIS technology across various industries. However, the Asia Pacific region is expected to witness the highest growth rate during the forecast period, primarily due to rapid urbanization, government initiatives promoting GIS adoption, and increasing investments in smart city projects. Other regions such as Europe, Latin America, and the Middle East & Africa are also experiencing significant growth in the GIS Data Collector market, thanks to increasing awareness and adoption of GIS technology.

The role of a GPS Field Controller is becoming increasingly pivotal in the GIS Data Collector market. These devices are essential for ensuring that data collected in the field is accurate and reliable. By providing real-time positioning data, GPS Field Controllers enable precise mapping and spatial analysis, which are critical for applications such as urban planning, agriculture, and transportation. The integration of GPS technology with GIS systems allows for seamless data synchronization and enhances the efficiency of data collection processes. As the demand for real-time spatial data continues to grow, the importance of GPS Field Controllers in the GIS ecosystem is expected to rise, driving further innovations and advancements in this segment.

Component Analysis

The GIS Data Collector market is segmented by component into hardware, software, and services. Each of these components plays a crucial role in the overall functionality and effectiveness of GIS systems. The hardware segment includes devices such as GPS units, laser rangefinders, and mobile GIS devices used for field data collection. The software segment encompasses various GIS applications and platforms used for data analysis, mapping, and visualization. The services segment includes consulting, training, maintenance, and support services provided by GIS vendors and solution providers.

In the hardware segment, the demand for advanced GPS units and mobile GIS devices is increasing, driven by the need for accurate and real-time spatial data collection. These devices are equipped with high-precision sensors and advanced features such as real-time kinematic (RTK) positioning, which enhance

The global HD map market for autonomous driving is projected to be valued at $2.3 billion in 2024, driven by factors such as increasing consumer awareness and the rising prevalence of industry-specific trends. The market is expected to grow at a CAGR of 16%, reaching approximately $9.8 billion by 2034.

Get key insights from Market Research Intellect's Automotive Gps Parts Market Report, valued at USD 12.5 billion in 2024, and forecast to grow to USD 20.8 billion by 2033, with a CAGR of 7.5% (2026-2033).

The Geospatial Analytics Market size was valued at USD 79.06 USD billion in 2023 and is projected to reach USD 202.74 USD billion by 2032, exhibiting a CAGR of 14.4 % during the forecast period. The growing adoption of location-based technologies and the increasing need for data-driven decision-making in various industries are key factors driving market growth. Geospatial analytics captures, produces and displays GIS (geographic information system)-maps and pictures that may be weather maps, GPS or satellite photos. The geospatial analysis as a tool works with state of art technology in every formats namely; the GPS, sensors that locates, social media, mobile devices, multi of the satellite imagery to produce data visualizations that are facilitating trend-finding in complex relations between people and places as well are the situations' understanding. Visualizations are depicted through the use of maps, graphs, figures, and cartograms that illustrate the entire historical picture as well as a current changing trend. This is why the forecast becomes more confident and the situation is anticipated better. Recent developments include: February 2024: Placer.ai and Esri, a Geographic Information System (GIS) technology provider, partnered to empower customers with enhanced analytics capabilities, integrating consumer behavior analysis. Additionally, the agreement will foster collaborations to unlock further features by synergizing our respective product offerings., December 2023: CKS and Esri India Technologies Pvt Ltd teamed up to introduce the 'MMGEIS' program, focusing on students from 8th grade to undergraduates, to position India as a global leader in geospatial technology through skill development and innovation., December 2023: In collaboration with Bayanat, the UAE Space Agency revealed the initiation of the operational phase of the Geospatial Analytics Platform during its participation in organizing the Space at COP28 initiatives., November 2023: USAID unveiled its inaugural Geospatial Strategy, designed to harness geospatial data and technology for more targeted international program delivery. The strategy foresees a future where geographic methods enhance the effectiveness of USAID's efforts by pinpointing development needs, monitoring program implementation, and evaluating outcomes based on location., May 2023: TomTom International BV, a geolocation technology specialist, expanded its partnership with Alteryx, Inc. Through this partnership, Alteryx will use TomTom’s Maps APIs and location data to integrate spatial data into Alteryx’s products and location insights packages, such as Alteryx Designer., May 2023: Oracle Corporation announced the launch of Oracle Spatial Studio 23.1, available in the Oracle Cloud Infrastructure (OCI) marketplace and for on-premises deployment. Users can browse, explore, and analyze geographic data stored in and managed by Oracle using a no-code mapping tool., May 2023: CAPE Analytics, a property intelligence company, announced an enhanced insurance offering by leveraging Google geospatial data. Google’s geospatial data can help CAPE create appropriate solutions for insurance carriers., February 2023: HERE Global B.V. announced a collaboration with Cognizant, an information technology, services, and consulting company, to offer digital customer experience using location data. In this partnership, Cognizant will utilize the HERE location platform’s real-time traffic data, weather, and road attribute data to develop spatial intelligent solutions for its customers., July 2022: Athenium Analytics, a climate risk analytics company, launched a comprehensive tornado data set on the Esri ArcGIS Marketplace. This offering, which included the last 25 years of tornado insights from Athenium Analytics, would extend its Bronze partner relationship with Esri. . Key drivers for this market are: Advancements in Technologies to Fuel Market Growth. Potential restraints include: Lack of Standardization Coupled with Shortage of Skilled Workforce to Limit Market Growth. Notable trends are: Rise of Web-based GIS Platforms Will Transform Market.

This file contains the flight trackline Global Positioning System (GPS) point data from the aerial surveys. Surveys were flown at 60 meters (200 feet) above sea level at 160 kilometers per hour (90 knots) ground speed. The surveys were flown in a high-winged, twin engine Partenavia PN 68 Observer aircraft following methods developed for seabirds by Briggs et al. (1987). GPS points were recorded every five seconds to allow adequate spatial coverage of the trackline (222 meters is traversed every five seconds at the survey speed of 160 kilometers per hour) and to limit the size of the resulting data files. Data was collected using a laptop computer running the program dLOG (R.G. Ford Consulting, Inc.) that allowed us to simultaneously collect coordinates (NAD27 map datum) and sea surface temperature (SST, degrees Celsius [°C]) determined via a belly-mounted, digital infrared radiation pyrometer (Heitronics™ KT19.85; measurement interval = 1 s, response time = 3 ms, emissivity = 0.99). SST values were appended to GPS flight data based on date and time. Observers sat on both sides of the aircraft and scanned the sea surface through bubble windows. Each of two observers counted and identified seabirds and marine mammals occurring within a 50-meter strip on their side of the aircraft for a total maximum strip-width of 100 meters when both observers were surveying simultaneously. At least one observer surveyed at all times, but individual effort was discontinued when glare obscured greater than 25% of an observer's field of view. To ensure that we maintained a strip width of 50 m, we estimated sighting angles from the aircraft to the water using clinometers. Observers rechecked sighting angles with a clinometer several times during each survey. These data are associated with the following publication: Mason, J.W., McChesney, G.J., McIver, W.R., Carter, H.R., Takekawa, J.Y., Golightly, R.T., Ackerman, J.T., Orthmeyer, D.L., Perry, W.M., Yee, J.L. and Pierson, M.O. 2007. At-sea distribution and abundance of seabirds off southern California: a 20-Year comparison. Cooper Ornithological Society, Studies in Avian Biology Vol. 33. References- Briggs, K.T., W.B. Tyler, D.B. Lewis, and D.R. Carlson. 1987. Bird communities at sea off California: 1975–1983. Studies in Avian Biology 11.

Discover the latest insights from Market Research Intellect's Location And HD-MAP Unit Market Report, valued at USD 2.5 billion in 2024, with significant growth projected to USD 7.8 billion by 2033 at a CAGR of 15.5% (2026-2033).

The US Location-based Services (LBS) market is experiencing robust growth, driven by the increasing adoption of smartphones, the proliferation of location-aware applications, and the expanding use of LBS across various sectors. The market, a significant segment of the global LBS landscape, benefits from a highly developed technological infrastructure and a large consumer base receptive to location-based technologies. While precise figures for the US market size in 2025 aren't provided, considering a global market size "XX million" and a CAGR of 14.24%, and assuming the US holds a significant portion (e.g., 30-40%) of the global market, a reasonable estimate for the US market size in 2025 would be in the range of $50-70 billion. This growth is propelled by several key drivers, including the increasing demand for improved navigation and mapping solutions, the rise of location-based advertising and marketing strategies, and the expanding use of LBS in logistics and supply chain management for enhanced efficiency and tracking capabilities. The integration of LBS with IoT devices and big data analytics further amplifies market potential, creating opportunities for advanced location intelligence and personalized services. However, challenges like data privacy concerns, security vulnerabilities, and the need for robust infrastructure development in certain areas could potentially hinder market growth. The market segmentation within the US reveals significant opportunities across diverse sectors. The hardware segment, encompassing GPS receivers, sensors, and other location tracking devices, is expected to witness considerable growth due to technological advancements. The software segment, which comprises location-based applications and platforms, is anticipated to be a major revenue generator, fueled by the increasing demand for user-friendly and feature-rich applications. The services segment, offering consulting, integration, and maintenance services, will also experience growth alongside the expanding market. In terms of application, mapping and navigation continue to dominate, with business intelligence and analytics showing rapid expansion as companies leverage location data for decision-making. The end-user segment is diverse, with transportation and logistics, IT and telecom, and healthcare among the key adopters of LBS technologies. North America, particularly the US, is projected to maintain its position as a dominant market due to its technological sophistication, strong digital infrastructure, and widespread smartphone penetration. Continued innovation in areas such as augmented reality (AR) and virtual reality (VR) integration with LBS is expected to open new avenues for growth in the years to come. Recent developments include: June 2023: The Air Force Research Laboratory (AFRL) formed a strategic partnership with Luminous Cyber Corp. to develop a highly resilient alternative to GPS. This initiative is aimed at addressing regions where GPS coverage is unreliable or susceptible to interference from malicious actors. Luminous Cyber Corp. specializes in the development of Alternative-Position Navigation and Timing (A-PNT) solutions for various applications, including crewed and uncrewed orbital, avionic, marine, and mounted land-based systems., September 2022: Hot Pepper Mobile, a mobile phone developer, and NextNav, a leading player in next-generation GPS technology, announced a groundbreaking agreement. This partnership is set to introduce NextNav's cutting-edge Pinnacle vertical location technology to Hot Pepper Mobile's upcoming feature phone, which will operate on a tier-one carrier's network. This collaboration will enable the integration of z-axis geolocation capabilities, which have become increasingly crucial for 911 emergency services, search and rescue operations, and lone employee safety.. Key drivers for this market are: Surge in demand for LBS (Location-Based Service) and RTLS (Real-Time Location Systems) for industry applications, Growing Demand for Geo-based Marketing. Potential restraints include: Surge in demand for LBS (Location-Based Service) and RTLS (Real-Time Location Systems) for industry applications, Growing Demand for Geo-based Marketing. Notable trends are: Indoor Location Segment is Expected to Hold Significant Share of the Market.

Global Digital Map market size is expected to reach $37.13 billion by 2029 at 15.8%, rise of location-based marketing fuels growth in the digital map market

Tile Download Link Ortho Imagery - As the prime contractor, Bradstreet Consultants, Inc. used the aerial photography flown in one session on April 23-26, 2007, by The Sanborn Map Compay, Inc. of Charlotte, NC who acquired approximately 4,000 photos @ a resolution of 0.5' pixel (similar to 1"=600') with airborne GPS using a Z/I Digital Mapping Aerial Camera. Bradstreet Consultants, Inc. painted and repainted ground targets for photo survey control points (~400) to support full analytical aerotriangulation. The aerotriangulation solution was used to set up each stereopair of photos for orthorectification and DTM compilation. The ortho imagery was rectified from the natural color digial imagery employing a digital terrain model (DTM) collected from the 2007 imagery and supplemented from updating some town's original DTM and some town's from scratch using the imagery in softcopy (digital) stereoplotter in the Kork KDMS and DAT/EM AutoCAD DWG format.

This Mat-Su Borough road centerlines dataset contains assigned official road names, address ranges, and cartographic classifications. This data is used to create the MSAG table for the Enhanced 9-1-1 program and is suitable for geo-coding purposes. Note: Cartographic classification of roads now includes a classification of "NOT CONST'D" which denotes roads that have been platted but not yet constructed. Original data was aggregated by a consultant (McLane Consulting of Soldotna, AK) as a part of the original addressing/911 project. Centerlines were interpolated from existing digital CAD drawings of property and ROW lines. Consultant (McClane) then did field work to append the centerline file to include additional road segments not represented as part of ROW within the property maps. Additional segments were input using GPS and "heads up" 85 digitizing methods. Each was adjusted to fit with the existing data. Data was originally stored in MapInfo (MIF) format and later converted to ESRI shapefile (SHP) format. Additional data related to the state highway system was collected using GPS technology between 1997 and 1999 by the Alaska Department of Transportation. This data was used to supplement the Borough data set for portions of the Parks Highway, Glenn Highway, Old Glenn Highway, Petersville Road, Denali Highway, and Lake Louise Road. Replacement of those street segments based upon property map interpolation but now available within the AK-DOT GPS collection is planned for Summer 2001. Data is maintained in an ongoing basis, primarily taken from subdivision plats, right-of-way plats, or other similar documentation of road existence. Data is input based on road centerlines as shown on subdivision plats and using "heads up" digitizing from aerial imagery.