I owned this one: https://web.archive.org/web/20231104153749/http://retro-gps.... (Lowrance GlobalNav Sport) 160 x 160 pixel display. It weighed 2 pounds with batteries.

It provided latitude, longitude, and heading.

Thought I would use it hiking but it was just too big to be anything but a toy. You inserted a cartridge, specific to your geographic area, if you wanted it to display names of towns/cities (data on the cartridges):

https://www.ebay.com/itm/314936082464

It did have "waypoints" (lat/long bookmarks, essentially) that allowed you to plot a line as you traveled. It could tell you how far you were to different waypoints you'd previously entered. IIRC, it had a serial connection for waypoint download to a PC. People tried sharing waypoint series -- "routes" -- but it just never really had much success as I recall. It was just too cumbersome.

It was mounted in a travel case where the lid removed exposed the control panel. I want to say it was about the size of a shoe box. Similar in length and height to one of those hinged metal ammunition cans, but wider if I remember correctly. It seemed hefty enough to have a lead-acid battery inside, but they did not give details.

You set it on the ground and waited minutes for a fix. Then it just displayed numeric grid coordinates of your location with segmented digit display cells somewhat like a 1970s calculator.

My first GPS receiver was an old Magellan. I can't recall the model, but mid 90s, very basic features. Eventually after turning it on it would get a fix, and give you coordinates / speed / bearing. No names of towns or anything like that though it did have support for some number of waypoints.

I typically used it for multi week hikes through the rockies where I was navigating primarily with topo maps & compass, and about once a day I'd turn on the GPSr to validate my location. It was too much of a pig on batteries to use it any more often, but, it was a reasonable size for hiking.

Totally different world vs the Garmin GPSMap 66i I currently use, but, I'd probably trust the old Magellan more than I do 66i on week/longer excursions.

    > about once a day I'd turn on the GPS to
    > validate my location.

The idea with many of these early devices was exactly what you're describing, experienced hikers who'd mainly use a map & compass to navigate might buy these. It was enough to have one GPS for the entire group, and on a typical trip with good visibility and orientation the GPS might never come out of the backpack.

But knowing where you are if you manage to completely lose orientation (e.g. with an onset of fog) is invaluable. The original use case for GPS devices for hikers was that sort of fallback safety.

Thanks for sharing this, I never had the chance to see one of these units. It's so weird now to imagine GPS with no map!

P.s. What does a six-channel GPS receiver even mean? Is more channels more better?

The operating principle of GPS is more complex than I can usefully summarise in a comment, but essentially the satellites are continuously broadcasting an extremely accurate time signal that the receiver uses to calculate the time-of-flight to each satellite. GPS receivers need signals from a minimum of four satellites to provide a location fix.

There are usually more than four satellites visible, so additional channels allow for more than the minimum number of signals to be received. this can provide improved accuracy, faster time-to-first-fix and better resilience to interference. If you're receiving five or six signals, you don't lose your positioning fix when one of the satellites moves below the horizon or is obstructed by terrain. Reflected signals can cause error, because the time-of-flight of the signal will be greater than the actual distance to the satellite; extra channels allow these errors to be compensated for.

For a long time, GPS receivers typically had no more than 12 channels, which was the maximum number that would actually be useful given the limited number of satellites in the original GPS constellation. Since then, many other navigation satellite constellations have launched, so between 40 and 60 navigation satellites are typically visible at any moment. Receivers have commensurately improved, with even basic receivers often having upwards of 48 channels.

https://www.ebay.com/itm/314936082464

The antenna flipped up and doubled as a screen protector:

http://retro-gps.info/photos/files/page2-1023-full.jpg

https://i.ebayimg.com/images/g/zxUAAOSwDspimA3F/s-l1600.jpg

Sorry, I don't remember what 6-channel means. I would guess it could receive data from up to 6 satellites? Don't know.

IIRC, this cost about $700 but cartridges were extra. Very expensive for the time. It worked without the cartridges, but I think it only displayed lat/long then, or in any case much more limited info. The carts added more info like town/city/state.

Unfortunately, I could not find any YouTube videos of early GPS receivers.

What a spiffy looking unit, it looks like belongs mounted in the dash of a 198x Mercedes, Porsche, Corvette, Bronco, or similar alongside one of those old school built-in car phones.

Archive links of the eBay resources:

1a. https://web.archive.org/web/20231104152903/https://www.ebay....

1b. https://archive.ph/QxwrN

2a. https://web.archive.org/web/20231104153359/https://i.ebayimg...

2b. https://archive.ph/crpGm

(Adding because of how many broken eBay links I've encountered on forums over the years.. it's always frustrating, haha.)

https://web.archive.org/web/20231104153749/http://retro-gps....

> The receiver has six channels that continuously track four primary GPS satellites and sequentially acquire and track all other visible and healthy satellites on the fifth and sixth channels.

So one the voltage may have been too low and two the usable loge might have been too short for these power hungry devices

Nickel metal hydride, and specifically Eneloops, were a game changer, as their self-discharge was only 10%/month, and had virtually no charge cycle memory.

While modern GPS can get a position fix pretty quick, a cold start on standalone units can still take a while before it discovers enough satellites.

The crazy thing to me is now days my little tiny watch can do Wifi, Several Bluetooth protocols, 5G, NFC, Wireless charging and probably some other stuff I'm forgetting about. Oh and it supports a variety of global navigation satellite systems. Don't forget the high-res OLED display too. And the fact it is fully watertight.

All that while having a fairly impressive battery life.

Just like now, the Soviet Union was under heavy sanctions, and they weren't allowed to receive the latest computer tech. The various companies had ways around this, though, and the saying was that they'd purposefully design their boards so that Russian engineers could "tamper" with them in order to achieve higher than allowed clock speeds.

Anyway this cute board just made me think of that, so thought I'd share it.

https://ciechanow.ski/gps/

Comes with a lot of animations and interactive elements. Admittedly, I haven't gone through all of it yet since it so detailed, but it is marvelous.

Earlier discussion:

https://news.ycombinator.com/item?id=36180316

I think it was called differential post correction but if you had a base station with a known location you could snap your incorrect points to the difference generated at that correction level and get the true location after the fact.

Source: GIS major in late 90s when this stuff was a lot more magical

Selective Availability?

This requires raw GNSS measurement data support which is not available in most consumer units and is an incredibly proprietary mess in the professional surveying equipment space. It was actually Google who improved the status quo by mandating pseudorange support in Android.

Neat history of GPS units

http://retro-gps.info/page33/index.html

But what's really interesting is the first GPS watch, the Forerunner 101 in 2003

https://www.garmin.com/en-US/p/231

https://en.wikipedia.org/wiki/Precision_Lightweight_GPS_Rece...

Was hoping there was an actual answer for that question. Or am I missing something? Otherwise reads like "good question, who fucking knows!? certainly not me the person making the assertion!"

https://www.ebay.com/itm/274506300217