Surveys

Rodger Logan Ski Chaste Lake USA Water Ski Technical Controller

    

The Water Ski Homologation program and files can be collectively downloaded and installed from: http://www.waterski-softwares.com/ . This program includes the Homologation Report software as well as the various survey files.

Note: If you use Google Chrome, it will report the program as “potentially malicious” as it does all executable files. We recommend the use of IE.

Once downloaded, the program is titled “Waterski Homologation” and will be listed along with your other installed programs. Executing it will allow you to create homologation reports and/or the various survey files.

This presentation is based, primarily, around the Topcon Total Station series. However the majority of information is applicable to all instruments.

Welcome Page

Activity Choice Menu

Element Choice Drop Down Menu

Choose “Ranking List” for Record capability “Polar” for single point measurement or “3 station” for 3 point angle only measurement

Mid Gate 1&2 to Mid Gate 3&4 Check Box for “Reflectorless Total Stations Buoy Diameter for “Reflectorless” sights

8 Buoy course example

The European way of numbering things is: St1, St2 and St3 are the cells for the theodolite stations. You only fill these in if you are doing a 2 or 3 station survey. It doesn't matter where these stations are but obviously the greater the baselines, the more accurate your survey will be. If you are doing Polar you ignore these because your instrument will give you angle and distance.

Slalom PG = Slalom pre-gates. 1,2 on the left (as you look at the course) and 3,4 on the right G = slalom gate buoys. again 1,2 on the left (as you look at the course) and 3,4 on the right S = slalom skier turn buoys. 1,3,5, closest to you and 2,4,6 on the far side B = boat lane buoys. 1,3,5,7,9,11 closest to you and 2,4,6, 8, 10, 12 on the far side Tr = tower for slalom gate cameras. 1 on the near shore and 2 on the far shore Jump you have 15 and 19 followed by , ST, MT, ET, & EC for start time, mid time, end time and end course. There is also NT but ignore these as they are no longer used.

R1 and R2 are the top corners of the ramp (you don't need to use R). R1 is always furthest away from the course Trick: G= start buoy. 1 on the left and 3 on the right PG = 50m buoy 1 on the left and 3 on the right Video jump element: This will just give you x and y co ordinates for any buoy you want. It doesn't matter which system you are using, Corson, Splasheye, Bottcher, Loreto. The smart thing is, before you survey, to make a little drawing for yourself of the set-up and write on it what you are going to call each buoy. Then you fill in the ones you need in the program. Generally, Corson people name their buoys ABCD et.c. and Bottcher use 20. 30,60 et.c. but it really doesn't matter what you call them as long as you know. If you are using a bottcher system you need to survey the camera positions. With Corson, no need.

I suggest you play around with both systems and find what you are comfortable with.

You should eventually be able to use any system in any configuration or even no pre-written software at all. You can use sketch-up if you want or Autocad or a slide rule. It is the answer that matters.

     Remember that the buoy numbering system for Slalom is different from Dave Clark’s. The Lion survey retains the same logic for the pregates, gates and boat guides as the skier buoys. That is: facing down course, all buoys to the right are odd numbered, all buoys to the left are even numbered.

The value entry schema for degrees/minutes/seconds is Deg.MinSec. For example 93°47’22” would be entered as 93.4722

Note that leading zeros are unnecessary.

It’s also important to understand that, in contrast to Dave Clark’s “Least Squares/Best Fit” approach, the Lion method complies with IWWF Rules which defines the Slalom centerline as a line extended from midway between the gate buoys. Therefore, a significant error in the position of those buoys can muck everything up. Likewise, the jump course is based along a line between the 15ST and 15MT buoys.

It’s therefore possible that a course could be in compliance with one method and not the other. In the dozen or so courses that I have surveyed and have occasionally plugged the numbers into Dave’s spreadsheet, I haven’t found one.

Colored buoys represent the sight result.

Crosses are the ideal location

The instrument must be in SD mode to transmit data. The program will only use the HD and H data

Use Topcon_GPT.theo for single point EDM sights.

Topcon_GPT_Angle .theo for 3 point angle only sight

Typical ASCII data string transmitted from a Topcon in “Slope Distance” mode Note If doing a 3 point angle only sight, the instrument must be in HR mode i.e.ANG

button

This is a sample “Element” printout.

Note the absence of min/max columns for space constraints.

Buoy Hat