A Procedure For Deriving Geo-Referenced Location For Digital Images

ABSTRACT Two systems of bilinear interpolation were studied in deriving a procedure for transforming geo-referenced grid locations to locations on maps defined by digital image column and line coordinates. Map data were from 1 : 50.000 Universal Transverse Mercator topographic charts. and digital data were from SPOT satellite dataprocessed to Level lb (CHES. 1979). corrected for Earth rotation and curvature and off-nadir viewing but without local control. Two independent data sets gave similar results: models with two independent variables gave prediccted errors of less than the dimensions of one pixel of the digital data. Models with one independent variable were inadequate for satisfactory transformations. Procedures for collecting and analyzing control data are presented. and trial models are shown and discussed. Kata Kunci.: deriving geo referenced - digital image

The clinical and hemodynamic results after axillary – to – popliteal vein valve transplantation

AbstractPurpose: To evaluate the results of axillary vein to popliteal vein valve transplantation (VVTX), we reviewed the clinical, phlebographic, and noninvasive hemodynamic results in 15 patients.Methods: All patients had postthrombotic destruction of deep venous valves as determined by ascending phlebography, whereas descending phlebography demonstrated grade III or IV reflux in all patients. A segment of valve-bearing axillary vein was transplanted to the popliteal vein in the affected limb. Postoperative evaluation was by clinical, noninvasive, and phlebographic means.Results: Over a mean follow-up period of 5.3 years (1.25 to 11 years), 13 of 14 patients (93%) had symptomatic improvement with relief of swelling, whereas all 14 patients who were admitted with pain had relief after operation. Thirteen of 15 patients (87%) returned to work or household duties. Physical findings of edema, skin pigmentation, and lipodermatosclerosis improved in most patients. Only three patients (21%) had development of recurrent ulcers, with an average postoperative ulcer-free interval of 4 years by life-table analysis. The cumulative ulcer-free survival rate for the group averaged 62% at late follow-up. All three patients with ulcer recurrence had a functioning valve by descending phlebography, but recurrent perforating veins were found in two patients, and deep venous thrombosis above a patent VVTX was observed in the third. Late assessment of reflux by venous filling index and valve closure times for the entire sample demonstrated mean values of 4.9 seconds in the latter and 6.8 ml/sec in the former. Residual volume fraction, which correlates with invasive ambulatory venous pressures, was reduced to a mean of 31%. No deterioration in late sequential noninvasive values could be detected.Conclusion: VVTX is a durable procedure for preventing recurrent venous ulcers. (J V ASC S URG 1995;21:110-9.