Volume 13, Number 2: April/May 2007

Page 2 – The Vice Provost for University Libraries reflects upon the strides made in the last year. Page 3 - Ornithologist David Sibley’s Edwin Way Teale lecture is featured. Page 5 - In a guest column on diversity issues, Professor Hedley Freake examines what UConn is doing to engender cultural understanding in students. Page 6 - Staff anniversaries and awards. Page 7 - Finding articles, images, and music easier with new database locator.

Position Errors Caused by GPS Height of Instrument Blunders

Height of instrument (HI) blunders in GPS measurements cause position errors. These errors can be pure vertical, pure horizontal, or a mixture of both. There are different error regimes depending on whether both the base and the rover both have HI blunders, if just the base has an HI blunder, or just the rover has an HI blunder. The resulting errors are on the order of 30 cm for receiver separations of 1000 km for an HI blunder of 2 m. Given the complicated nature of the errors, we believe it would be difficult, if not impossible, to detect such errors by visual inspection. This serves to underline the necessity to enter GPS HI's correctly.