This site is actually a benchmark (C5LG) with an accurately determined position (enough for this purpose, anyway).
There was a film cannister cache to be found at this site but don't worry if it is not there - you can still log a find by providing the requested data. The real objective of this cache is to experiment with GPS error by comparing the readings of different GPS units, at different times, different conditions, etc. As a result, both cache finders and setters may get an appreciation for errors in placement or during the search.
Your web site log entry should contain the following, as well as any other comments. It MUST at least contain your lat/long reading to constitute a find. See the example entry in the logs.
| Lat/Long: |
Note your coordinates in decimal degrees format, as this gives more precision than decimal minutes. (decimal degrees = minutes / 60). You can also enter your coordinates explicitly by checking the 'Add a waypoint to the log' box when entering your log.
If you like, you can get more precision than your GPSr possibly displays by downloading your waypoints. |
| Altitude: |
Height above Mean Sea Level (MSL). You will need to put the GPSr on the ground for this. |
| GPSr Model: |
|
| GPSr software version: |
|
| Time: |
Particularly night or day |
| EPE: |
Estimated Position Error |
| Waypoint Time: |
How long did you let the GPSr sit at this position before taking the reading? |
| Satalite Configuration: |
For each satalite with a fix, indicate:
- Id number
- Quadrant [NE, SE, SW, NW]
- Altitude [Low (from the horizon to 45°), or High (from 45° to zenith directly above)]
- Reception%
and calculate the average reception.
Or take a picture of the GPS display if you can. |
| Battery Level%: |
Percentage of power supply remaining |
| Battery Mode: |
Power Save or Normal? Any Simulation entries will be deleted ;-) |
| Sky condition: |
Eg, clear, overcast, raining |
| Extras: |
An external antenna? |
Each log will be plotted on the graph below, showing their relative positions from the benchmark coordinates.
For those interested, see the Testing Accuracy thread that started this off.
Final Analysis:
| Statistic |
Coordinates |
Number Logged |
Distance from GZ |
Colour |
| 194 coords that are within range (less than 8m) of GZ. Only those within 6m are shown on the graph. 17 were outside the range (most probably due to logging the trig instead of the benchmark). |
|
194 |
|
Blue |
| The exact coords (GZ) as published by LINZ are very accurate and unlikely to be reproduced by standard hand held units |
S 36° 52' 40.65237"
E 174° 45' 53.97480" |
0 |
0 |
|
| Precise coordinates. Degrees logged to more than 5 decimal places |
|
7 |
|
Purple |
| Most logged |
S 36° 52.677
E 174° 45.900 |
26 |
117.6cm |
Teal |
| Published Geocache coordinates |
S 36° 52.678
E 174° 45.900 |
11 |
105.5cm |
Green |
| Closest coordinates (Tufty and JDHnz) |
-36.87796, 174.76499 |
2 |
28.9cm |
Fuchsia |
| Average coordinates |
-36.877960, 174.764996 |
|
28.4cm |
Red |