# Horizontal reductions

Hello,

When I set up 100 meters for horizontal reduction , my project does not work.

Thank you very much.
Nguyen

## Horizontal reductions

Hello Nguyen,

When I set up 100 meters for horizontal reduction , my project does not work.

I take a look to your provided coordinate files. Here, the UTM zone number is missing and, thus, the simple check of your coordinates failed, i.e.,

if (yS >= 1100000 && yS <= 59800000 && yE >= 1100000 && yE <= 59800000) {
// do reduction
}

kind regards
Micha

--
applied-geodesy.org - OpenSource Least-Squares Adjustment Software for Geodetic Sciences

## Horizontal reductions

I don't know how JAG3D recognize the UTM or Gauss coordinates. I add 48 to the Y coordinate for the UTM and my project has just done.

Thank you very much.
Nguyen

## Horizontal reductions

One question: if my UTM coordinates in 3 zone width (0.9999 scale). How to reduce to this one?

In your programing, I see you use the reduction in 6 zone width (0.9996 scale).

## Horizontal reductions

Hi,

One question: if my UTM coordinates in 3 zone width (0.9999 scale). How to reduce to this one?

The zone width is defined to 6°, cf. UTM zone definition. If you have a special (local) projection, you have to reduce the distances by your own, defined by your special crs.

Please note, all projections are applied only to horizontal distances (but not to slope distances!).

/Micha

--
applied-geodesy.org - OpenSource Least-Squares Adjustment Software for Geodetic Sciences