通过上世纪八九十年代对数字摄影测量的研究、开发与推广，进入21世纪，我国数字摄影测量以世人难以想象的速度发展，数字摄影测量工作站在中国的摄影测量生产中获得了普遍的应用与推广，摄影测量的教学也由过去只有少数院校才能进行的“贵族”式的教学得到了极大的普及。目前，全国至少有40多所大专院校的测绘工程专业开设摄影测量课程，这极大地拓宽了摄影测量所需人才的培养渠道。
  由于摄影测量生产的转型，影像扫描仪已被大量应用，全国扫描仪数量已超过100台。同时航空摄影机也在加速引进。应用于航空摄影过程中的GPS／IMU系统也已引进，Z／I公司的数字航空摄影机也已
经开始在中国应用。
  与此同时，高分辨率的遥感影像、以及其定位参数文件的应用，只要极少量的外业控制点，就能迅速生成正射影像图，它已在城市、土地的变迁、规划中得到愈来愈广泛的应用。航空激光扫描雷达也愈
来愈成熟。所有这一切表明，新一代传感器、定位系统的迅速发展以及数字摄影测量工作站的大规模推广，都对摄影测量自身的发展提出一个非常严峻而现实的问题：摄影测量向何处去？
  数字摄影测量发展的新契机
  从20世纪初起，以纯精密、光机的模拟摄影测量仪器为特征的摄影测量一直持续了半个多世纪。在此期间，摄影测量的教学、极少量的科研，除所谓的变换光束理论研究以外，多数是围绕欧洲的几个著
名厂商生产的模拟摄影测量仪器进行。到50年代末计算机开始进入摄影测量，摄影测量的研究领域得到了很大的扩展：如解析法空中三角测量、在线空中三角测量、区域网平差、粗差检测理论、正射纠正、
数字测图等。90年代随着数字摄影测量时代的到来，相对于传统的模拟、解析摄影测量，其最大的特点是将计算机视觉、模式识别技术应用到摄影测量，实现了内定向、相对定向、空中三角测量、数字高程
模型（DEM）生成等的（半）自动化。数字摄影测量不仅仅将传统摄影测量仪器各种功能全部计算机，以提高工效、降低对作业员的要求，而且正在不断地扩充摄影测量的功能。
  但是我们必须清醒地认识到：一些数字摄影测量工作站只是解析测图仪的替代品；目前的数字摄影测量工作站主要只适合于航空、航天摄影测量，而近景、地面摄影测量与它有很大差异，将数字摄影测
量应用于近景摄影测量，摄影测量的理论必须进一步发展；即使是当前自动化程度较高的数字摄影测量工作站，摄影测量的主要研究还仅仅在“同名点”的影像匹配技术。因此，我们必须跳出传统摄影测量
的束缚，必须从计算机的特点考虑数字摄影测量的理论发展，这正是数字摄影测量为其理论与实践的发展提出了崭新的契机，例如：灭点理论与应用、广义点理论与应用和多基线立体理论与应用。

  数字摄影测量发展的重要方向
  当前数字影像、DEM、摄影机位置、姿态数据的直接获取等技术正在迅速发展，它们对于加快摄影测量成图周期、减少野外工作量将发挥愈来愈重要的作用。例如利用高分辨率的卫星影像与对应的有理
多项式系数（RPC）定位数据文件，再加以极少量的GPS点作控制，即能快速生产1：1万乃至1：5000的正射影像图。但是，与此相对应的摄影测量自身的发展与任务是什么？这是一个摄影测量工作者必须回答的问题。
  不管数据获取手段如何发展，航空（航天）摄影测量发展的中心任务之一是数据更新，实现建立国家基本地形图的由定期更新到动态更新机制。特别是对于处于经济快速发展的我国，GIS数据更新显得
尤为重要。
  但是，数据更新不是重测地形图，具体而言：

  数据更新的复杂性   利用航空摄影的影像进行测绘，纵然在模拟测图期间，其生产流程、各种规范已经成熟，到解析、特别是数字摄影测量时代，摄影测量的流程虽然有很大的改变，但是基本任务与规
范没有根本的变化。而数据更新则不同，其情况比“新测或重测”要复杂得多。它的复杂性来自如何利用已有数据，减少外业、内业的工作量，加速成图周期。由此就产生很多问题，必须予以考虑，例如：
已有的数据是什么？是正射影像图＋DEM，还是线划图＋DEM？数据更新的地区是什么？是城区、郊区、还是山区？更新的地形图比例尺，是大比例尺，还是小比例尺？等等。
  例如在郊区、山区、小比例尺地图数据更新时，可以利用“新影像”与已有的“正射影像图＋DEM”直接进行配准，进行无（或减少）控制点的空中三角测量。但是对于城区、大比例尺地形图更新，就很难利用已有的正射影像图，在更新城区、大比例尺地图时，利用已有的线划图将比影像图更为有利。
  数据更新涉及摄影测量理论的创新与技术的更新   数据更新问题是如何利用已有的“数据”，更确切而言是如何利用已有的“信息”。众所周知：欲利用新影像更新已有地图，将两者“叠合”是最重要的
一步。为此，确定影像的方位元素，将影像纠正为与地图一致的正射影像图，然后才能将“图”与像”套合。因此在数据更新中，除常用于传统的人工选取点作为控制点以外，能否利用地图上大量存在的
“线状地物要素”作为控制，对于实现数据更新自动化、提高工效至关重要。
  数据更新涉及变化检测，建立动态更新机制由于地物、地貌的变化带来数据更新的需求，以及随着测绘成果的应用愈来愈广泛，特别是地理信息产业的发展，测绘成果的应用已经超出了经济、国防建设
的范畴，而进入人们的生活。例如汽车导航的广泛使用，人们对道路更新的要求很高，因此“定期更新”已经不能满足要求，其提法也不科学，而应该按需要建立“动态更新”机制。
  要建立动态更新机制，其技术核心是“变化检测”，虽然当前国内外对于变化检测已有大量的研究，但多数是对部分要素的少量试验，距实用尚有很长的距离。对于国家测绘局基本地形图的动态更新机制，可以采用“从粗到细”的技术路线，例如在更新全国1：5万地形图的同时统计出地图的变化率，以确定1：1万地形图是否需要更新，从而建立一套比较合理、实用的全国基本地形图的动态更新机制。
     数据更新涉及观念的更新、规范的修改传统的摄影测量是由外业“控制点”、内业“加密点”与“碎部点”的等级之分，由外业“控制点”、进行空中三角测量获得“加密点”，最后是测绘“碎部点”，
精度的要求当然是“上一级高于下一级”、“上一级控制下一级”进行测绘。内业测图是在加密点的控制下进行测绘地形图的碎部点、或进行正射纠正，因此加密点的精度应该高于地形图上的碎部点与影像
图上的明显点。但是，在上述数据更新方法中，更多的是考虑应用地形图或影像图上的碎部点或明显点作为新一轮成图的控制（注意：被用作控制的碎部点的数量要比传统的控制点数量多出几十倍、甚至几
百倍），由此生产的新一轮地图，但是它能否到达成图要求，当然还需作大量的验证。同时，更新方案也应该而且必须考虑加入少量的外业控制点、使用上一轮成图时影像的外方位元素、加密点与对应的影
像，在可能的条件下应考虑应用定位定向系统（POS）数据等。但是，不管采用何种方案，多涉及传统观念的更新与相应规范的修改。

  摄影测量发展的崭新领域
  到目前为止数字摄影测量的发展，无论在理论上还是在实际上，主要是围绕着利用航空（航天）摄影测量测绘地形图，而对于数字近景（地面）摄影测量的研究甚少。同时随着数码相机的广泛应用、价
格愈来愈低廉，数码相机在测量的应用将是摄影测量发展的必然趋势。

  在此领域它与计算机视觉有着天然的密切联系，因为“计算机视觉的研究目标是使计算机具有通过二维图像认知三维环境信息的能力，这种能力将不仅使机器感知三维环境中物体的几何信息，包括它的形状、位置、姿态、运动等，而且能对它们进行描述、存储，识别与理解”，两者非常相似，但是又有明显的差异。同样，数字近景摄影测量与基于传统的基于单基线立体、测标的近景摄影测量也有很大的差别。
  数字摄影测量应该是一门相对年轻的学科，由于它利用计算机替代“人眼”，使得数字摄影测量无论在理论上还是其实践都将得到迅速发展。它将在三维可视化、地理信息数据更新、数字近景摄影测量
等方面得到广泛的应用与发展。它对国家基本图更新与其现势性将会显得愈来愈重要。

Through the eighties and nineties of the digital photogrammetry research, development and promotion of the 21st century, China's digital photogrammetry to the world unimaginable speed the development of digital photogrammetric workstations, photogrammetric production in China has gained widespread application of with the promotion of the teaching of photogrammetry is also only a small number of institutions from the past can be conducted in a "noble" type of teaching has been a great popularity. At present, there are at least more than 40 colleges and universities set up the mapping project of the professional photography course, which greatly expanded the photogrammetric the requisite human resources cultivation.
   Photogrammetric production due to the transformation, image scanner has been a large number of applications has exceeded the national scanners 100. At the same time the camera is also accelerating the introduction of air. Used in aerial photography in the process of GPS / IMU system has also been introduced, Z / I digital aerial camera company has also been
The application began in China.
   At the same time, high-resolution remote sensing images, as well as its position parameter file the application, as long as a very small amount of foreign trade control points, we can quickly generate orthophoto maps, it has been in the city, the land changes, planning to get more Getting more and more widely used. Airline laser scanning radar is also more
Getting more and more mature. All of this shows that a new generation of sensors, positioning systems, as well as the rapid development of digital photogrammetric workstations, large-scale promotion, are all self-development of photogrammetry to raise a very serious and real problem: Photogrammetry go?
   Digital photogrammetry new opportunities for the development of
   From the beginning of the 20th century, to pure precision, analog-ray machine is characterized by photographic measurement instruments for Photogrammetry continued for over half a century. During this period, the teaching of photogrammetry, a very small amount of scientific research, in addition to the so-called transformation of the beam theory, most of the few in Europe with around
Name manufacturers of analog photogrammetric instruments. To the late 50s entered the computer photogrammetry, photogrammetry research areas has been greatly extended: If the analytical method aerial triangulation, on-line aerial triangulation, local area network adjustment, gross error detection theory, orthographic correction
Digital mapping and so on. 90 years with the era of digital photogrammetry, compared with traditional analog, analytical photogrammetry, its biggest feature is the computer vision, pattern recognition techniques applied to photogrammetry, to achieve the inner orientation, relative orientation, aerial triangulation, DEM
Model (DEM) generation, etc. (semi-) automation. Digital Photogrammetry Photogrammetry is not only the traditional instruments features all of the computer in order to improve work efficiency, reduce operational staff requirements, and is constantly expanding photogrammetric functions.
   However, we must clearly understand: Some digital photogrammetric workstation is analytic mapping instrument alternatives; current digital photogrammetric workstations, primarily suitable only for aviation, space photogrammetry, while close-range, ground Photogrammetry and it has a very different , will measure digital photography
The amount applied to close-range photogrammetry, photogrammetry theory must be further developed; even higher degree of automation is the current digital photogrammetric workstations, photogrammetric the main study only in the "same name point" image matching techniques. Therefore, we must go beyond the traditional photogrammetric
Bondage, we must take into account the characteristics of the computer theory of the development of digital photogrammetry, which is digital photogrammetry for the development of the theory and practice put forward a new opportunity, for example: Vanishing Point Theory and Applications, broad and multi-point theory and application of baseline three-dimensional theory and application.

   Digital photogrammetry an important direction of development
   Current digital image, DEM, camera position, attitude data, direct access to such technology is advancing rapidly, they are accelerating the photogrammetric mapping cycle, reducing the workload of the field will play an increasingly important role. For example, using high-resolution satellite images and the corresponding rational
Polynomial coefficients (RPC) positioning data file, coupled with an extremely small number of GPS points for control, that can quickly produce a 1:1 million, as well as 1:5000 Orthophoto Map. However, with this corresponding photogrammetric own development with the task? This is a photogrammetric workers must answer.
   No matter how the data acquisition means to develop aviation (aerospace) Photogrammetry is one of the central tasks of the development of data update, to achieve the establishment of the state's basic topographic map by the periodic updates to the dynamic update mechanism. Especially for rapid economic development in our country, GIS data update appears to
Is particularly important.
   However, the data update is not a re-test topographic maps, in particular:

   The complexity of data update images using aerial photography for mapping, even in simulated mapping during the course of the production process, a variety of specifications has come to resolve, especially in the era of digital photogrammetry, photogrammetry process despite significant changes in , but the basic tasks and Regulation
Fan has not been fundamentally changed. The data update is different, their situation than the "new testing or re-test" is much more complex. Its complexity comes from how the use of existing data, and reduce foreign industry, the workload within the industry to accelerate into the map cycle. Arise from many problems, must be considered, such as:
What is the existing data? Yes Orthophoto Map + DEM, or a line graph + DEM? What are the areas of data updates? Is urban, suburban, or mountains? Updated topographic maps scale, large scale or small scale? And so on.
   For example, in rural areas, mountainous areas, small-scale map data updates, you can use the "new image" and has been the "Orthophoto Map + DEM" direct registration, carried out without (or less) control points, aerial triangulation. But for urban areas, large-scale topographic maps updated, it is difficult to use the existing orthophoto map, update the urban areas, large-scale maps, the use of existing DLG more favorable than the image map.
   Photogrammetric data update involved in the theory of innovation and technology update data update problem is how to use the existing "data", more precisely in terms of how to use the existing "information." As we all know: To use the new video update existing maps, the two "composite" is the most important
Step. To this end, determine the image orientation element to correct the image in line with the Maps Orthophoto Map, before the "Map" and as "nested. Therefore, data update, in addition to commonly used in the traditional manual selection as a control point point outside the possibility of using a large number of exist on the map
"Linear features and physical objects" as the control for the automation of data update and improve work efficiency is essential.
   Data update involved in change detection, create a dynamic update mechanism is due to surface features, topography data update brings changes in demand, as well as the increasingly wide range of surveying and mapping applications of the results, especially in geographic information industry development, surveying and mapping applications of the results have exceeded the economy, national defense construction
Areas, while access to people's lives. For example, the extensive use of car navigation, it is very demanding on the road updates, so "regular updates" has been unable to meet the requirements, its formulation is not scientific, but should be necessary to establish a "dynamic update" mechanism.
   To create a dynamic update mechanism, its technical core of which is "change detection", while the current home and abroad for change detection has been a lot of research, but most of the elements is part of a small number of tests, from the utility still a very long distance. For the National Mapping Bureau of the basic topographic maps of the dynamic update mechanism, can be used "from coarse to fine," the technical route, for example, updating the national topographic map 1:5 million map, while the statistics of the rate of change to determine the topography of 1:1 million, Figure it needs to be updated in order to establish a more reasonable and practical basic topographic maps nationwide dynamic update mechanism.
      Related to the concept of updating data update, standardize the changes of traditional photography industry, measurement is from the outside "control points" within the industry "encrypted point" and "broken the Ministry of points" graded on a scale from outside the industry, "control points" for air triangulation to obtain "encrypted point", and finally mapping "broken the Ministry of points"
Accuracy requirement of course, is "on the one above the next level" and "one under the control of a" mapping. Mapping within the industry is under the control of the encryption point mapping topographic map Department of broken points, or ortho-corrected, so encrypted point accuracy should be higher than the Ministry of topographic maps on a broken point and image
The obvious point of the map. However, in the above-mentioned data updating method, is to consider the application of more topographical map or image map of the broken point of the Ministry of points or obvious as a new one into a graph control (Note: is used as the control of the Ministry of points, the number of pieces to be the number of control points than the traditional a few more times, and even a few
A hundred times), resulting in production of a new round of maps, but its ability to reach a map requests, we need to make a lot of validation. At the same time, update the program also should and must take into account a small amount of foreign trade control points, the use of a mapping when the image exterior orientation elements, encryption points and the corresponding shadow
Like, if possible, should be considered under the conditions of application of location and orientation system (POS) data. However, whatever the program, more than the traditional concepts related to the update and the corresponding specification changes.

   The development of new areas of Photogrammetry
   So far, the development of digital photogrammetry, both in theory and in practice, mainly around the use of air (space) photogrammetric mapping topographic maps, and for digital close-range (ground) photogrammetry little studied. Meanwhile, along with the extensive application of digital camera, price
Grid more affordable, digital cameras, the application of the measurement will be the inevitable development trend of Photogrammetry.

   It is in this area has a natural and computer vision in close contact, because "computer vision research goal is to make the computer through the two-dimensional images with three-dimensional environment information of cognitive ability, this ability will not only make the machine perception of three-dimensional geometric objects in the environment information, including its shape, position, posture, exercise, etc., but can describe them, storage, identification and understanding "between the two are very similar, but there are significant differences. Similarly, digital close-range photogrammetry and based on the traditional single-baseline stereo based on measured object close-range photogrammetry have great difference.
   Digital photogrammetry should be a relatively young discipline, since it replaced the use of computers "human eye", making digital photogrammetry both in theory and its practice will be developed rapidly. It will in three-dimensional visualization of GIS data update, digital close-range photogrammetry
And so widely used and development. It updates the state's basic map will appear with the current trend of increasingly important.