of Compass Points 1

The journal of the BCRA Cave Surveying Group, September 1993

Welcome -Editorial

A welcome to the first Compass Points, and a news of what's going on in the surveying world.

Lighting Suuntos - Bob Buecher

First a short piece from Bob Buecher, first published on the Cavers' Forum email discussion list (see later). He details an effective way of lighting your Suunto instruments with surface mounted LEDs.

Survex Release - Wookey/Olly Betts

Next is a discussion of some of the issues facing surveying and surveyors in this country. Some words on how thinking about these started the SURVEX project which addresses some of these issues. Then a summary of SURVEX functionality is given.

Reading List - Wookey

We have a list of articles to complement Dave Irwin's list of required reading for those interested in surveying on computers.

What is Least Squares, and why use it? - Olly Betts.

The least squares system of error distribution is used by many survey programs. Olly Betts endeavours to remove the mystique about it and explain why it is the most appropriate way to deal with data containing the sort of random errors associated with normal survey data. There are those who think that loop closure in any form is not a good idea, because it merely hides errors in the data. They have a point, but dealing with gross errors is a separate issue from dealing with the normal errors generated by the survey process. Systems to deal best with this (gross error) problem remain a subject for further work.

Calibration Data Analysis - Wookey

By way of some non-computing matter, an analysis of calibration data, gained on 4 years of CUCC Austria expeditions is included. It arguably raises more questions than it answers.