Overview

No matter what your interests are or what field you work in, spatial data is always being considered whether you know it or not. Spatial data, also known as真命天子patial data, is a term used to describe any data related to or containing information about a specific location on the Earth’s surface.

See more:为什么你应该关心空间数据

The Basics

空间数据可以以各种格式存在,并且包含更多的位置特定信息。为了正确理解和了解有关空间数据的更多信息,有几个关键术语将帮助您更流利地掌握空间数据的语言。

Vector

Vector example

矢量数据最好被描述为现实世界的图形表示。有三种主要类型的矢量数据:点,线条和多边形。连接点创建线条,以及创建封闭区域的连接行创建多边形。载体最适合用来在地球表面上呈现对象或特征的概括。传染媒介数据和称为shapefiles(.shp)的文件格式有时可互换使用,因为矢量数据最常存储在.shp文件中。

Raster

Raster example栅格数据是在像素网格中呈现的数据。栅格内的每个像素具有值,无论是一种颜色还是测量单位,以传送有关所讨论的元素的信息。栅格通常是指图像。然而,在空间世界中,这可以具体地指的是从卫星或其他空中装置拍摄的照片。光栅数据质量根据分辨率和手头的任务而异。

属性

Spatial data contains more information than just a location on the surface of the Earth. Any additional information, or non-spatial data, that describes a feature is referred to as an attribute. Spatial data can have any amount of additional attributes accompanying information about the location. For example, you might have a map displaying buildings within a city’s downtown region. Each of the buildings, in addition to their location, may have additional attributes such as the type of use (housing, business, government, etc.), the year it was built, and how many stories it has.

地理坐标系

To identify exact locations on the surface of the Earth, a geographic坐标系用来。通常,x和y轴用于数学系统,但在地理中,轴被称为纬度(水平线运行的水平线)和经度(北方南北运行的垂直线)。每个轴表示该线相对于地球的中心定向的角度,因此单位以度(°)测量

*more on projections and coordinate systems below

Georeferencing and Geocoding

Georeferencing and geocoding are different but similar processes since both involve fitting data to the appropriate coordinates of the real world. Georeferencing is the process of assigning coordinates to vectors or rasters so they can be oriented accurately on a model of the Earth’s surface. The data used in geocoding are addresses and location descriptors (city, country, etc.). Each of these locations is given the exact coordinates of reference for that location on the surface of the Earth.

使用空间数据

什么是GIS?

The most common way that spatial data is processed and analyzed is using a GIS, or,geographic information system。这些是程序或与用户一起工作的程序组合,帮助用户了解其空间数据。这包括管理,操纵和自定义,分析和创建视觉显示。用户通常会一次使用多个空间数据集,并将它们与它们相互联系。每个空间数据集可以称为图层。

If you were using GIS for a municipality project, you might have vector data like street data (lines), neighbourhood boundary data (polygons), and high school locations (points). Each dataset would exist as its own layer in your GIS. Placement of layers is important for visual purposes as it will help you understand the various types of data and present your findings in an easily understandable way. In this case, you would want to make sure that high school points and street lines are layers above neighbourhood boundaries. Otherwise, you would not be able to see them.

GIS的领域和研究远远超过数字测绘和制图。它包括各种类别,包括空间分析, remote sensing, and geovisualization. In these GIS fields, the spatial data becomes much more complex and difficult to use.

除了栅格和矢量数据之外,还有LiDAR data(also known as point clouds) and 3D data. LiDAR data is data that is collected via satellites, drones, or other aerial devices. 3D data is data that extends the typical latitude and longitude 2-D coordinates and incorporates elevation and or depth into the data. While complex, this data is rich with information and can be used to solve a variety of problems pertaining to the Earth’s surface.

使用空间数据for Graphics

地图是一个常见的做法展示空间data as they can easily communicate complex topics. They can help validate or provide evidence for decision making, teach others about historical events in an area, or help provide an understanding of natural and human-made phenomena.

When creating visuals, graphics, or maps with spatial data, there are a variety of geographic elements to consider. One of the most important and coincidentally most problematic elements is projection. The projection of a map describes the way that the Earth’s surface, a three-dimensional shape, is flattened and presented on a two-dimensional surface. No projection is perfect and depending on your projection you may be sacrificing accuracy in shape, area, distance, or direction.

The City of Vancouver is presented in each of these different projection types. Image a. is using the projection UTM83-10 which is the standard projection used for displaying the City of Vancouver. Image b. is projected using CANBC-Poly resulting in a slightly rotated version of image a. Image c. is projected using LLWGS-84 and is distorted in shape.

Maps can also be used to present what are typically non-visual elements of society. For example, the occurrence of certain events, income level, any demographic descriptor, or relationships like the number of heat strokes in an area compared to temperature. A simple display method is a classification map, also known as a choropleth map.

Choropleth Maps跨空间轻松地传达差异,一致性或模式。Choropleth地图中的分类区域将具有不同的边界,而展示现象的浓度或密度的热图具有模糊界限。分类或热图可以用作汽车事故或犯罪等其他变量的底层,以突出某些趋势和潜在的相关性。

Image A. Shows the locations where graffiti has been identified by city custodians in the City of Vancouver 一种。
图像B.来自位置数据的Choropleth Map b.
图像C.来自位置数据的热图 c.
上面的图像演示了可以显示空间数据的几种不同方式。图像a。显示了在温哥华市的城市监护人识别涂鸦的地点。图片b。使用相同的点位置数据,但将信息显示为Choropleth Map。城市地区边界以不同的颜色突出显示,以描述这些社区内的涂鸦的密度或数量。图像c。使用原始点位置数据集创建热图。在这种情况下,城市地区并不兴趣,而是显示整个城市的涂鸦发生的传播或模式。

使用空间数据for Statistics

As it is with any data, to truly make sense of spatial data and understand what it is saying you must perform some level of statistical analysis. These processes will help you uncover answers and lead you to make better decisions for your organization. The major difference between spatial data and all other types of data when it comes to statistical analysis is the need to account for factors like elevation, distance, and area in your analytical process.

While needing to account for additional variables about a location may be intimidating, many spatial statistic processes are quite similar to basic statistical methods. For example, interpolation can help you estimate or predict the value of a sample, and spatial interpolation can help you estimate or predict the value of a variable in a sample location. Similarly, spatial autocorrelation measures the degree of similarity between sample locations just like typical autocorrelation is done.

其他类型的空间数据

While spatial data has long been used for analyzing and presenting the Earth’s surface, it is not limited to the outdoor environment. There are many architectural, engineering, and construction (AEC) companies that use CAD (computer-aided design) and BIM (building information model) data in their day-to-day activities. While CAD and BIM may not necessarily be thought of as traditional spatial data, they and other AEC formats also need to consider many spatial elements to understand their work.

Mapping is also no longer limited to the natural world. Indoor mapping and wayfinding are becoming much more popular especially in large buildings and institutions like malls, arenas, hospitals, and campuses. This field of study is new but shows no signs of stopping. Everyone has a smartphone these days and uses it to help them navigate the natural world, so why not help people navigate the indoors too?

FME and Spatial Data

FME用于空间数据集成

While there are many tools and software that can help you make use of spatial data, FME is the software of choice for those that need tointegrate their spatial data。Safe Software and FME came into existence because of this exact problem. Spatial data varies widely and is often stuck in formats that cannot be easily used by all applications, making it extremely difficult for GIS experts to make use of all the information they have. While it was possible to转变专有格式过去,大部分数据都将丢失conversion。Thus, FME was born.

What is FME?

FME is recognized as the data integration platform with the best support for spatial data worldwide. However, it can handle much more than just spatial data and can be easily used by IT and business professionals. FME supports 450+ formats which makes it a flexible data integration tool for those dealing with a large variety of data formats.

Safe Software, the makers of FME, are leaders in the technology world that strive to stay one step ahead of the data integration trends. FME is continuously upgraded to ensure it has been adapted to support new data formats, updated versions of data formats, and large amounts of data. Gone is the idea that individual departments must work in their data silos, with IT structures limiting the company’s potential to truly work as one. Data should be able to flow freely no matter where, when, or how it’s needed.

Related Resources

为什么你应该关心空间数据

What is Geospatial Data?

38 Common GIS Tasks in FME

地理数据库与地理空间数据库:有什么区别?

8+ Ways to Visualize Spatial Data in a Web Browser