Another theoretical session with maps, grid systems and so forth. Last time I had to search for good resources online whereas now I am back home continue reading my beloved Ultimate Navigation Manual by Lyle Brotherton.
I went through what I learned last time came up with some distinct tips/facts for myself that I learned/refreshed:
- To remember that latitude is the horizontal lines I think of “my lats runs horizontally over my back, thus latitude is horizontal lines”.
- It is approximately 110 km between 1 degree of latitude.
- Latitude and longitude measurements in degrees, and 1 °= 60′ (minutes) = 60 ” (seconds)
I read up shortly on UTM and MGRS, both are grid systems. UTM divides the earth surface (2D) into 60 zones where each zone has 20 latitude bands. MGRS is the military grid reference system which NATO and the US military uses. The MGRS uses different notations but is based on UTM.
UTM describes a point on the map by using the name of the current zone, the easting location and northing location, e.g. 10S 707100E 4341200N. This means zone 10S, west-east line 707, north-south line 4341. The last 3 digits for easting and northing is (in meters and using 1000 m grids) how many meters from line 707 and 4341 to the east and north respectively the point is located, i.e. 100 m. east of the 707-line and 200 m north of the 4341-line.
I did some training in taking out coordinates in the UTM grid system using maps online.