GPS receivers: Difference between revisions

Revision as of 18:36, 30 April 2006

My interest is in learning how to do as much as possible for the least cost. I have a Garmin eMap and a Garmin GPS 25-LVC module, and Trimble Ace II and Trimble Lassen SQ modules. I recently got a Magnavox GPS reference station.

For hobbyists probably the best place to turn is [Spark Fun Electronics], they have a bunch of other modules that I don't list here yet.

Model	Accuracy	Channels	Price	Comments
eMap	15m/2m	12	$200 or so	Handheld, accepts RTCM for DGPS. Apparently a bad choice for Rinex software
GPS 10	15m/3m WAAS	12	$250	bluetooth module
GPS 15	15m	12		bare module
GPS 16 LVS, 16 HVS, 16A 3.3-6V / 6-40V / 8-40 V	15m / <3m WAAS / 3-5 USCG RTCM	12 channel		2 serial ports, deck mount
GPS 17			$200	basically the same as a GPS 16 but in a white, pole mount case
GPS 18	15m / 3m WAAS	12	$130	CMOS serial or RS232 or USB hockey puck
GPS 25-LVC (3.6-6V), -LVS(3.6-6V RS232), -HVS(6-40V RS232)	15m / 5m DGPS	?		bare module; capable of raw data output (pseudorange and phase) [1]
GPS 35 / 36	15m / 5m DGPS	?		35 = mouse style, 36 = pole mount

The GPS 17 is designed for marine applications but is often pressed into service in backpack style data collectors.

GPS modules

Model	Accuracy	Channels	Connectors		Price (est)	Comments
Pathfinder Pocket	10m/2m DGPS	8	2 RS232 via one DB9, SMB 3.3v, power		$500	includes an external antenna.
M-Loc	10m (no DGPS)	12		3.3v 35mW(68mW) 25 x 25 x 6.9 mm	$45	FirstGPS software runs on host processor
Lassen SQ	6-9m,no DGPS	8	8 pin header, H-FL-R-SMT	3.3v/100mW 26x26x6 mm, 5.7g	$45 (use IQ instead!)	Use w/RF transition cable
Lassen IQ	5-8m,no DGPS	12	8 pin header, H-FL-R-SMT	3.3v/85mW 26x26x6 mm, 5.7g	$50	Updated more accurate version of SQ. Purchase from SparkFun
Ace II	25m/2m DGPS	8	8 pin (2 CMOS TTL serial) SMB 5v/25mA	5v / 95mA / .47W 82.6 x 46.5 x 11.5 mm	cheap	Discontinued but I got one from eBay for $10
Ace III	25m/2m DGPS	8	8 pin (2 CMOS TTL serial) SMB 5v/25mA	5v / 95mA / .47W 82.6 x 46.5 x 11.5 mm	$80
Lassen SK-8	25m/2m DGPS	8	8 pin (2 CMOS TTL serial) SMB 5v/25mA		$	Discontinued; use SKII
Lassen SKII	25m/2m DGPS	8	8 pin (2 CMOS TTL serial) SMB 5v/25mA	5V / 95mA(120mA)/ .47W(.60W)	$80
Lassen LP	25m/2m DGPS	8	2 serial and power via 8 pin header, MCX/3.3v 12mA	3.3V / 55mA(67mA)/ .182W(.221W) 66.167 x 31.75 x 12	$55	Low power; can be programmed to power up/down on schedule

Style	Gain	Connector	Price
Micropatch	26dB	5m cable with MCX	$17
Hardmount micropatch	26dB	TNC	$
Bullet	35dB	22m cable with SMB adapter	$

ToppTec -- purveyors of Trimble OEM modules

Consumer grade; Earthmates are WAAS enabled but the older Tripmates are cheap on eBay if you just need a NMEA GPS source.

Model	Accuracy	Channels	Price	Comments
Tripmate	15m?	12	$20-30 on eBay	rs232 (discontinued)
Earthmate	WAAS	12	$100	USB
Blue logger	WAAS	12	$150	bluetooth enabled

People make boxes that simulate NMEA-capable devices to allow testing when the actual data stream is not available and to enable regression testing.

@@ Line 164: / Line 164: @@
 There is an
 [http://www.gfz-potsdam.de/pb1/staff/gbeyerle/opengps/ Open Source GPS Simulator]
-=== GPS mission planning software ===
-A GPS mission consists of three phases. planning, execution, and post-processing.
-Mission planning software packages run on a desktop system at your office and assist with planning and post-processing phases.
-The two commercial programs that I know of are tightly integrated with the field software so they are not all that useful unless you buy in to the whole enchilada -- data collector, proprietary data collector software, and "office" software.
-The two programs are [http://www.trimble.com Trimble] [[GPS Pathfinder Office]] for use with [[Trimble data collectors]] and [http://www.tdsway.com TDS] [[SoloOffice]] which works with TDS [[SoloField]].
-Planning for a GPS mission should include checking for suitable conditions.
-This includes knowing that the satellites will be positioned propitiously when you
-will be in the field.
-I use Trimble's free planning program for this.
-You can download it from [insert Trimbles download site].
-The bad part is that it is available only for Windows systems but it's handy enough
-that I use it anyway.