Using the ISS tacking page, based in London UK Longitude of 000.000000. Question, on the pass details the Logitude is given as a positive number from 000.000000 to 359.999999 but it appears to be 'inverted' for example when ISS is west of the Greenwich meridian, somewhere over the Atlantic the longitude is given as 027.092977 but no W(est) indicator but on the same pass as ISS travels eastwards across mainland Europe the longitude is now given 330.695173 but no indicator. The convention when giving longitude without an E(ast) or W(est) indicator is that 001 is 1 degree East of Greenwich, 180 is over the Pacific and 359 is 1 degree west of Greewich. I think a line of code in your computer programme possibly needs 'correcting'. But other than that 'small' failing I find you tracking page must useful. Keep up the good work.. Kris G8AUU [ Professionally I operate a MES (Mobile Eatrh Station), 14 GHz uplink, for satellite news gathering. Both in the UK and the rest of the world. Monitoring ISS repeater round the world makes for a little stress relief from the location pressure of news gathering]