From 3cc0cfd478dbf94652ba37d85567d0ab93049e31 Mon Sep 17 00:00:00 2001 From: "U-ATSAUVS\\heath.raftery" Date: Tue, 9 Aug 2016 08:44:37 +1000 Subject: [PATCH] Corrected precision figure for lat/long values. Added derivation and an example. --- README.md | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/README.md b/README.md index f229a45..ae9f235 100644 --- a/README.md +++ b/README.md @@ -40,7 +40,9 @@ to either fixed-point or floating-point format: The compound type ``struct minmea_float`` uses ``int_least32_t`` internally. Therefore, the coordinate precision is guaranteed to be at least ``[+-]DDDMM.MMMMM`` (five decimal digits) -or ±20cm LSB at the equator. +or ±2cm LSB at the equator. Note that GPS modules commonly only provide four deciminal digits +(``[+-]DDDMM.MMMM``), which equates to ±20cm (0.0001 minute is 0.0001/60 degrees and one degree +is about 111km) at the equator. ## Coordinate format