Which one of the following parameters is accurate for DGPS.

• Positional accuracies ~ 1 - 2 m if rover is less than 1-2 km from the reference station
• Positional accuracies ~ 2 - 5m if rover is less than 2-5 fm from the reference station
• Positional accuracies ~ 5 - 10 m if rover is less than 5-10 km from reference station
• Positional accuracies ~ 5 - 10 m if rover is less than 25 km