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The XIXth International Congress of Photogrammetry and Remote Sensing was held at the Amsterdam RAI International Exhibition and Congress Centre, the Netherlands, from 16th to 23rd July 2000. Reports are given on the Congress as a whole, including the General Assembly, some Technical Commission activities and the Congress Exhibition. Papers from the Congress are published in the International Archives of Photogrammetry and Remote Sensing, 33.

To study how blood supply of the esophageal and gastric stumps influences the anastomotic healing after esophagogastrostomy in rabbits.Twenty-seven New Zealand rabbits were randomly divided into 3 groups to receive esophagogastrostomy, followed by different procedures. Except for those in group I, all the rabbits were subjected to procedures of reducing the blood supply either of the esophageal or the gastric stump (group II and group III, respectively), followed by single-layer esophagogastric anastomoses using interrupted 5-0 polypropylene sutures. Ten days after operation, all the rats were killed and the anastomotic sites excised for measurement of the inner diameter, tensile strength, and hydroxyproline concentration.Healing of the esophagograstric anastomosis was obtained in all the rabbits but one with anastomotic leakage in group I and one with perforation of the gastric fundus in group III. The anastomotic inner diameters were similar in all the three groups, whereas the tensile strength and hydroxyproline concentration at the anastomoses decreased in group III in comparison with the other two groups (P0.05) that had similar measurements (P0.05).Extended length of the free esophageal stump does not significantly affect anastomotic healing as decrease of blood supply in the gastric stump.

Photogrammetry is increasingly involved in production of 3D walk-throughs and fly-throughs. This production is costly due to the current standard technique used for rendering, which relies on detailed polygon modeling and huge amounts of computation. The emerging image based rendering techniques are superior alternatives in that they require no polygon models and that the rendering speed is independent of scene complexity. In order to adapt photogrammetry to become more visualization capable, a new strategy named visualization first modeling second is proposed in the paper. This strategy facilitates the production of 3D walk- throughs directly from captured images using image-based rendering techniques. It makes interactive photogrammetric modeling more efficient by using 3D walk-through as user- interface. It also provides for joint use of images based and polygon based rendering to perfection 3D walk-through. The paper presents the detail of this new strategy after reviewing both rendering techniques.

The principle of the "camera-on-theodolite" calibration method is reviewed; no control field is required. Standard procedures and algorithms are presented for routine use of the method. The relevant image processing algorithms are described in detail. A sub-pixel shift method is proposed for assessment of the accuracy of target image location. The calibration results are analysed and the issue of the usability of the calibrated parameters is discussed. Using motorised theodolites, the method is particularly useful for fully automated calibration.

Realizing long distance entanglement swapping with independent sources in the real-world condition is important for both future quantum network and fundamental study of quantum theory. Currently, demonstration over a few of tens kilometer underground optical fiber has been achieved. However, future applications demand entanglement swapping over longer distance with more complicated environment. We exploit two independent 1-GHz-clock sequential time-bin entangled photon-pair sources, develop several automatic stability controls, and successfully implement a field test of entanglement swapping over more than 100-km optical fiber link including coiled, underground and suspended optical fibers. Our result verifies the feasibility of such technologies for long distance quantum network and for many interesting quantum information experiments.