You might have seen VisualGPS already, a free PocketPC and Windows package covered in other posts. Beeline GPS adds waypoint management features with Geocaching in mind. You can try all the features available in BeelineGPS free for 30 days.
With Beeline you get extra tabs for Trip, Analog Gauges (Panel) and Map. Not the moving kind, but a blank map where you can place icons associated to waypoints from more than a hundred available, including quite a few geared towards Geocaching. It also adds a whole set of waypoint management features where you can create, modify and annotate them. You can search nearby waypoints based in your current position within a range you determine. Notes and detailed info can be added to a given position including status for caches.
A GoTo option let you set a target and from that you will get all the necessary data at the Trip tab, including visual displays with bearings and range in the Map tab. Waypoints can be opened/saved as .GPX and .XML files and imported also from .LOC and .CSV files.
Like VisualGPS you have a tab showing the current position of the satellites in the sky, including their trails and another tab showing their signal strength and corresponding PRN's (Pseudo Random Number). BeelineGPS shows when WAAS is in use and also during a loss of a fix that 'dead reckoning' is being estimated. If you are curious about this one, Wikipedia defines Dead Reckoning as:
"the process of estimating a global position of a vehicle by advancing a known position using course, speed, time and distance to be traveled. That is, in other words, figuring out where you momentarily are or where you will be at a certain time if you hold the speed, time and course you plan to travel."Install
Before using Beeline GPS, make sure you run its Automatic Setup under Tools | GPS | Autodetect GPS... With that you will know for sure if your card sends all the required NMEA sentences used by BeelineGPS. Somehow I only got the Holux GM 270 Ultra (XTrac 2.0 firmware) which supports the RMC sentence to provide one after a factory reset with Winfast Navigator from Leadtek (Tools | Command...).
The $GPRMC sentence gives GPS status, position, speed over ground and course plus UTC value and even magnetic variation if implemented by the chipset (see below). Beeline GPS uses these values to calculate average speed, estimate arrival times and other data. You can configure a Sirf based receiver to send RMC sentences by selecting Tools | GPS | Manufacture Specific | Setup SiRF NMEA output.
Other packages instead of counting on the presence of the RMC sentence, calculate distance and speed based on point to point intervals from the GPGGA sentence. I was also able to get speed information from the corresponding RMC sentences with the GlobalSat BC 307 which runs Sirf firmware GSW2.
A RMC sentence looks like this
$GPRMC,171004.031,A,3658.4246,N,12201.3362,W,which translates to
171004.031 = UTC of position fix (hours, mins, secs, decimal secs)In this case the magnetic declination, the missing value after the comma is not being implemented by this Sirf chipset. The last value if a checksum.
A = GPS Status, Valid (V = invalid)
3658.4246,N = Latitude
12201.3362,W = Longitude
23.44 = Speed over ground in knots
255.42 = Course over ground, degrees, true
060206 = Day, Month, Year
By default a track is saved while you move around and it can be seen at the map tab, you can also record NMEA logs. With Beeline you lose the status tab, but you gain an altitude profile that can be displayed in the map tab and a waypoint averaging with DOP (Dillution of Position) threshold control for better accuracy.
You can set visual and audible alarms or even sound files to be activated when you approach a waypoint. The visual displays can use analog or digital modes for any of the available metrics displayed in the Trip tab, like your current speed for example.
From one to twelve displays can be arranged in several combinations in the Trip tab and up to four analog gauges (altimeter, compass, speed and vertical speed) can cycle in the Panel tab. Finally, the developer also makes available a paper on a NMEA Parser and the corresponding source code in C++ using MFC.
VisualGPS and BeelineGps offer great accuracy and position information, Differential GPS status,and in Beeline's case, dead reckoning and waypoint average. This is the kind of tool you would want to use to make precise measurements. There are similar packages offering moving maps in the market for equivalent cost and the free version already includes a lot of functionality. If you are into Geocaching or want to start getting into it check the free trial. A full license costs US$30 with all future updates made available for free.