Basic Tiling - Achieving the Desired Maplet Overlap

(compiled by DL)

Purpose: Basic tiling allows the user to generate a suite of maplets at a higher resolution which tile a region of interest. The overlap of the new maplets is controlled by the ratio of maplet ground sample distance (GSD) to bigmap scale. This 'How-To' explains how the user achieves the desired maplet overlap percentage.

Generating a Tiling Bigmap

The user must generate a bigmap which covers the region of interest and whose parameters are set up such that the new maplets will overlap by the desired amount.

Bigmap .in File

The user must adjust the bigmap pixel scale in the tiling .in file in order to achieve the desired maplet overlap ratio. This is done by applying a multiplicative factor to the maplet ground sample distance (GSD) as follows:

where F is the multiplicative overlap factor, such that:

For example:

• To achieve a 25% overlap:

  • maplet GSD = 10cm
    bigmap scale = 10cm * 1.5 = 15cm

Example set of multiplicative factors:

Example BGMAP1.in (for maplets with a GSD of 10cm and a 33% overlap):

m                                   <- To locate, reference to a map
START1                              <- Reference map name
   49 49                            <- Reference map pixel/line location
   0.00013  130  1.23400  1000      <- scale (km/pixel), Q size, integer random seed, maximum maplet scale
BGMAP1                              <- bigmap name
1                                   <- bigmap program commands
.005
.025
1
0
0
1
1
1
1
1
1
0
0