Up: Mission Peak main pageThe following table will give some idea of the accuracy of the elevations measurements made by the differentially corrected Garmin 12XL GPS. The "Map" numbers come from the "Ohlone Wilderness Regional Trail Permit," available from the East Bay Regional Park District at Sunol Regional Wilderness and Lake Del Valle. Of course it's possible that the GPS measurement is more accurate than the numbers on the map, whose method of determination is not specified. All numbers are in feet for ease of comparison to the map. From each GPS measurement, I subtracted 3 feet to account for the height of the GPS above the ground level during the measurement.
| Place | Map Elevation | GPS Elevation | ||
|---|---|---|---|---|
| Stanford Ave. staging area | 390 | 394 | ||
| Summit | 2517 | 2504 | ||
| Post 4, near privy | 2030 | 2008 | ||
| Post 7, Laurel Loop/Eagle Trail Junction | 2090 | 2087 | ||
| Post 8, Laurel Loop/Laurel Canyon Trail Junction West | 2010 | 1995 | ||
| Post 9, Laurel Loop/Laurel Canyon Trail Junction East | 1840 | 1828 | ||
| Post 11, near Calaveras Road | 770 | 771 | ||
| Post 12, Sunol Regional Wilderness sign-in board | 390 | 379 |
One likely source of discrepancy is that in some places (e.g. Stanford Staging Area), it's not clear where precisely the "Map" measurement was made. Another is that the zero reference for the map is not specified; there are various algorithms for determining what the local sealevel reference should be.
